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CORE ATLAS, APPENDIX B

B1 – Stratigraphic group boundaries

B2 – Formation and member boundaries

B3 – Vertical and lateral facies trends

B4 – Lithofacies

B5 – Diagenesis

B6 – Faults and fractures

Legend

Stratigraphic Group Boundaries

Figure B1a:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale is the black claystone interval between 2517.28 and 2517.58 m with a very sharp base. Below the Coppershale the Ten Boer Member is present comprising a series of interbedded claystones and fine to very fine sandstones. Note the bleaching of the sandstone bed directly underneath the Coppershale and the reduction spots around sandier patches at 2518.45 m. See Figure B5c for another example of bleached sandstone directly below the Coppershale.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B1a:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale is the black claystone interval between 2517.28 and 2517.58 m with a very sharp base. Below the Coppershale the Ten Boer Member is present comprising a series of interbedded claystones and fine to very fine sandstones. Note the bleaching of the sandstone bed directly underneath the Coppershale and the reduction spots around sandier patches at 2518.45 m. See Figure B5c for another example of bleached sandstone directly below the Coppershale.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B1b:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale in this well is the thin black claystone bed between 2663.76 and 2663.84 m. Below the Coppershale the Ten Boer Member is present in this well. The Ten Boer is characterized by interbedded claystones and fine to very fine sandstones which are structureless or have lenticular lamination and disturbed lamination and even show signs of rootlets. Note the color change from grey to reddish at the boundary of mudflat to wet sandflat sediments at 2664.75 m.

Well Slochteren-04 (SLO-04)

Figure B1b:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale in this well is the thin black claystone bed between 2663.76 and 2663.84 m. Below the Coppershale the Ten Boer Member is present in this well. The Ten Boer is characterized by interbedded claystones and fine to very fine sandstones which are structureless or have lenticular lamination and disturbed lamination and even show signs of rootlets. Note the color change from grey to reddish at the boundary of mudflat to wet sandflat sediments at 2664.75 m.

Well Slochteren-04 (SLO-04)

Figure B1c:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous sandstone. In this well the BPU was previously picked at 3579.26 m, at the base of a thick section of conglomerates and some sandstones. These overly a mature, red soil which is classified as Carboniferous. The conglomerate section is characterised by its red colour, mouldic porosity, absence of “sedimentary” clasts, and numerous erosional bed boundaries. It is overlain by a red claystone with typical Rotliegend Silverpit character. At the very base of this claystone on top of the sandstone of the conglomeratic section a thin conglomeratic bed of a few centimeters thickness is present, comprising sandstone clasts. Sandstone clasts are not observed in the conglomeratic section. In combination with palynological and geochemical analyses these observations point towards an updated position of the BPU picked at 3975.70 m.

Well K02-02

Figure B1c:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous sandstone. In this well the BPU was previously picked at 3579.26 m, at the base of a thick section of conglomerates and some sandstones. These overly a mature, red soil which is classified as Carboniferous. The conglomerate section is characterised by its red colour, mouldic porosity, absence of “sedimentary” clasts, and numerous erosional bed boundaries. It is overlain by a red claystone with typical Rotliegend Silverpit character. At the very base of this claystone on top of the sandstone of the conglomeratic section a thin conglomeratic bed of a few centimeters thickness is present, comprising sandstone clasts. Sandstone clasts are not observed in the conglomeratic section. In combination with palynological and geochemical analyses these observations point towards an updated position of the BPU picked at 3975.70 m.

Well K02-02

Figure B1d:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous claystone. The BPU in this well is picked at the change in lithology from Carboniferous (reddish) grey claystone to primarily coarse clastic deposits of the Rotliegend. The Carboniferous claystones are contorted to structureless with some rootlet traces. The conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Annen-Anlo-01 (ANL-01)

Figure B1d:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous claystone. The BPU in this well is picked at the change in lithology from Carboniferous (reddish) grey claystone to primarily coarse clastic deposits of the Rotliegend. The Carboniferous claystones are contorted to structureless with some rootlet traces. The conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Annen-Anlo-01 (ANL-01)

Figure B1e:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous sandstone. The BPU in this well is picked at the change in lithology from Carboniferous grey, fine-grained sandstone to the red conglomerate of the Rotliegend. The Carboniferous sandstone shows fine horizontal lamination to ripple lamination which is lightly contorted. The massive conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Slochteren-04 (SLO-04)

Figure B1e:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous sandstone. The BPU in this well is picked at the change in lithology from Carboniferous grey, fine-grained sandstone to the red conglomerate of the Rotliegend. The Carboniferous sandstone shows fine horizontal lamination to ripple lamination which is lightly contorted. The massive conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Slochteren-04 (SLO-04)

Figure B1f:

The Base Permian Unconformity (BPU): Rotliegend interbedded sandstone and claystone on Carboniferous claystone. The BPU in this well is picked at the change in lithology and colour from Carboniferous, grey claystone to red to light grey claystones and sandstones at 3466.03 m. The Carboniferous claystone is structureless to vaguely laminated and shows red oxidation spots and streaks. The Rotliegend claystones instead are typically brick red whereas the coarser-grained sandier intervals are whitish grey.

Well Norg-04 (NOR-04)

Figure B1f:

The Base Permian Unconformity (BPU): Rotliegend interbedded sandstone and claystone on Carboniferous claystone. The BPU in this well is picked at the change in lithology and colour from Carboniferous, grey claystone to red to light grey claystones and sandstones at 3466.03 m. The Carboniferous claystone is structureless to vaguely laminated and shows red oxidation spots and streaks. The Rotliegend claystones instead are typically brick red whereas the coarser-grained sandier intervals are whitish grey.

Well Norg-04 (NOR-04)

Figure B1g:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous claystone. In this well the BPU was picked at 3829 m LD = 3822.3 m DD at the base of a relatively thin sandstone interval which has just been cored (core to log shift approximately 6.5 m). However, inspecting the underlying red claystone interval more closely, a subtle change in texture and colour can be seen some 7 m below the sandstone. It grades downward from the typical brick red homogeneous to vaguely laminated Silverpit-like claystone to a slightly more purple distorted claystone. The former claystone can be attributed to the Rotliegend Hollum Member. Petrographical (Gokdag and van den Heuvel 1983 see well file G18-1 on www.nlog.nl) and preliminary results of biostratigraphical research suggest that this may well be the case. Therefore, an alternative BPU location is at approximately 3829.4 m.

Well G18-01

Figure B1g:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous claystone. In this well the BPU was picked at 3829 m LD = 3822.3 m DD at the base of a relatively thin sandstone interval which has just been cored (core to log shift approximately 6.5 m). However, inspecting the underlying red claystone interval more closely, a subtle change in texture and colour can be seen some 7 m below the sandstone. It grades downward from the typical brick red homogeneous to vaguely laminated Silverpit-like claystone to a slightly more purple distorted claystone. The former claystone can be attributed to the Rotliegend Hollum Member. Petrographical (Gokdag and van den Heuvel 1983 see well file G18-1 on www.nlog.nl) and preliminary results of biostratigraphical research suggest that this may well be the case. Therefore, an alternative BPU location is at approximately 3829.4 m.

Well G18-01

Figure B1h:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The issue here is the position of the BPU, which cannot be clearly resolved and is therefore questionable. On the operator′s composite log (ref. www.nlog.nl) the BPU is picked @ 3840.5 m (LD). An alternative location of the BPU based on core evaluation is @ 3828.2 m DD. After core to log-shift the BPU is set @ 3835.0 m LD. Arguments for assigning the interval 3835-3840 m LD to the Carboniferous are the combination of colour, sedimentary structures, hematite cementation, presence of mouldic porosity and the occurence of a thin, basal conglomeratic lag comprising clasts from the underlying sandstone.

Well K06-06

Figure B1h:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The issue here is the position of the BPU, which cannot be clearly resolved and is therefore questionable. On the operator′s composite log (ref. www.nlog.nl) the BPU is picked @ 3840.5 m (LD). An alternative location of the BPU based on core evaluation is @ 3828.2 m DD. After core to log-shift the BPU is set @ 3835.0 m LD. Arguments for assigning the interval 3835-3840 m LD to the Carboniferous are the combination of colour, sedimentary structures, hematite cementation, presence of mouldic porosity and the occurence of a thin, basal conglomeratic lag comprising clasts from the underlying sandstone.

Well K06-06

Figure B1i:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The BPU is picked within a sandstone unit at the base of a pebbly sandstone bed which ovelies a fractured sandstone. The fractures appear to be truncated by the pebbly sandstone.

Well J06-A-05

Figure B1i:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The BPU is picked within a sandstone unit at the base of a pebbly sandstone bed which ovelies a fractured sandstone. The fractures appear to be truncated by the pebbly sandstone.

Well J06-A-05

Formation and Member Boundaries

Figure B2a:

Sharp transition at 2708.5 m from grey fine-grained homogenised sandstones deposited as ephemeral, high-energy fluvial sediment of Upper Slochteren Member to overlying red-brown wavy-bedded claystones deposited in poorly drained mud and sandflat environments in the proximity of the perennial lake classified as the Ten Boer Member. This transition probably marks the onset of a regional rise of base level and expansion of the desert lake and can be confidently correlated to other wells in the area.

Well Slochteren-04 (SLO-04)

Figure B2a:

Sharp transition at 2708.5 m from grey fine-grained homogenised sandstones deposited as ephemeral, high-energy fluvial sediment of Upper Slochteren Member to overlying red-brown wavy-bedded claystones deposited in poorly drained mud and sandflat environments in the proximity of the perennial lake classified as the Ten Boer Member. This transition probably marks the onset of a regional rise of base level and expansion of the desert lake and can be confidently correlated to other wells in the area.

Well Slochteren-04 (SLO-04)

Figure B2b:

Gradually upwards-fining trend from medium-coarse-grained fluvial sandstones through a series of fine-grained, wavy-bedded muddy sandstones and finally to red to reddish brown horizontally laminated claystones deposited in a mudflat environment on the margin of a playa-lake. This is indicative of a more subtle expansion of the playa lake (Ten Boer Member) at the expense of gradually backstepping fluvial systems of the Upper Slochteren Member.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B2b:

Gradually upwards-fining trend from medium-coarse-grained fluvial sandstones through a series of fine-grained, wavy-bedded muddy sandstones and finally to red to reddish brown horizontally laminated claystones deposited in a mudflat environment on the margin of a playa-lake. This is indicative of a more subtle expansion of the playa lake (Ten Boer Member) at the expense of gradually backstepping fluvial systems of the Upper Slochteren Member.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B2c:

Center of basin during Silverpit Formation. Upper part of Silverpit Evaporite Member, basal section of a ca.10-m-thick halite-rich interval. Red claystone intermixed with halite crystal clusters in a brecciated fabric indicate an evaporite precipitation in a playa salt pan to evaporitic mudflat with frequent flooding and desiccation events. Brecciation is interpreted to be due to haloturbation and frequent changes of salt-ridge growth and partial dissolution of the interstitial evaporitic material. Layer of colourless to reddish compact halite has sharp and irregular boundaries to overlying and underlying brecciated halitic clay, which also contains nodules of anhydrite (subaerial pedogenic origin). Evidence for a perennial lacustrine standing water body such as laminated clay is absent.

Well E09-01

Figure B2c:

Center of basin during Silverpit Formation. Upper part of Silverpit Evaporite Member, basal section of a ca.10-m-thick halite-rich interval. Red claystone intermixed with halite crystal clusters in a brecciated fabric indicate an evaporite precipitation in a playa salt pan to evaporitic mudflat with frequent flooding and desiccation events. Brecciation is interpreted to be due to haloturbation and frequent changes of salt-ridge growth and partial dissolution of the interstitial evaporitic material. Layer of colourless to reddish compact halite has sharp and irregular boundaries to overlying and underlying brecciated halitic clay, which also contains nodules of anhydrite (subaerial pedogenic origin). Evidence for a perennial lacustrine standing water body such as laminated clay is absent.

Well E09-01

Figure B2d

Boundary between Slochteren Formation and the Silverpit Formation This is a relatively subjective lithostratigraphic boundary (reference Van Adrichem Boogaert et al 1993) because it is a gradual boundary from a sandstone-rich to a claystone-rich sediment series Here it is picked at , the top of the last definite sandstone bed occurring at 3954 m

Well K02-02

Figure B2d

Boundary between Slochteren Formation and the Silverpit Formation This is a relatively subjective lithostratigraphic boundary (reference Van Adrichem Boogaert et al 1993) because it is a gradual boundary from a sandstone-rich to a claystone-rich sediment series Here it is picked at , the top of the last definite sandstone bed occurring at 3954 m

Well K02-02

Figure B2e:

Boundary between the Hollum Member (Silverpit Formation) and the Lower Slochteren Member (Slochteren Formation). This is a quite sharp boundary picked at the base of the first prominent sandstone bed from the clay-prone Hollum Member at 3961.83 m. The Hollum Member predominantly comprises massive, red claystones but towards the top interbedded silt and fine-grained sandstone beds are more common.

Well K02-02

Figure B2e:

Boundary between the Hollum Member (Silverpit Formation) and the Lower Slochteren Member (Slochteren Formation). This is a quite sharp boundary picked at the base of the first prominent sandstone bed from the clay-prone Hollum Member at 3961.83 m. The Hollum Member predominantly comprises massive, red claystones but towards the top interbedded silt and fine-grained sandstone beds are more common.

Well K02-02

Vertical and Lateral Facies Trends

Figure B3a:

Example of lithofacies interpreted as being produced in desert environment as dune slipface deposits with coarser strata formed by avalanching of loose sand down the slipface, alternating with grain-fall laminae produced by deposition of fine-grained sand out of suspension. The predominance of normal grading, grain-fall strata, and compressional soft-sediment deformation structures suggest that only lower parts of dune foresets are preserved. The presence of multiple reactivation or bounding surfaces suggests changes in wind character. These sediments and their interpreted depositional environment are typical of the Slochteren Formation present at the Mid Netherlands High area representing an erg located on the lee side of a major fluvial trunk system in the East.

Well Westbeemster-01 (WBMS-01)

Figure B3a:

Example of lithofacies interpreted as being produced in desert environment as dune slipface deposits with coarser strata formed by avalanching of loose sand down the slipface, alternating with grain-fall laminae produced by deposition of fine-grained sand out of suspension. The predominance of normal grading, grain-fall strata, and compressional soft-sediment deformation structures suggest that only lower parts of dune foresets are preserved. The presence of multiple reactivation or bounding surfaces suggests changes in wind character. These sediments and their interpreted depositional environment are typical of the Slochteren Formation present at the Mid Netherlands High area representing an erg located on the lee side of a major fluvial trunk system in the East.

Well Westbeemster-01 (WBMS-01)

Figure B3b:

These sediments reflect deposition in a braided-stream and (upper) outwash-plain environment closely linked to the southern boundary of the Southern Permian Basin. This (repetitive) specific pattern of environments and their constituent sediments can be related to phases of hinterland uplift alternating with phases of basin fill. Uplift caused the spread of sheets of high-energy braided streams northwestwards passing laterally to thick blankets of sheetflood-deposited sandstones.

Well Slochteren-04 (SLO-04)

Figure B3b:

These sediments reflect deposition in a braided-stream and (upper) outwash-plain environment closely linked to the southern boundary of the Southern Permian Basin. This (repetitive) specific pattern of environments and their constituent sediments can be related to phases of hinterland uplift alternating with phases of basin fill. Uplift caused the spread of sheets of high-energy braided streams northwestwards passing laterally to thick blankets of sheetflood-deposited sandstones.

Well Slochteren-04 (SLO-04)

Figure B3c:

The photo shows the quite abrupt upwards change from a cross-stratified, fine–medium grained sandstone (S3l,xh) to a fine–medium grained adhesion-ripple sandstone showing vague horizontal (S2u,l) to wavy lamination and with a low detrital clay content. The cross-stratified sandstone is interpreted as an aeolian dune deposit whereas the wavy-bedded sandstone is interpreted to be deposited on a dry aeolian sandflat.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B3c:

The photo shows the quite abrupt upwards change from a cross-stratified, fine–medium grained sandstone (S3l,xh) to a fine–medium grained adhesion-ripple sandstone showing vague horizontal (S2u,l) to wavy lamination and with a low detrital clay content. The cross-stratified sandstone is interpreted as an aeolian dune deposit whereas the wavy-bedded sandstone is interpreted to be deposited on a dry aeolian sandflat.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B3d:

Facies succession from the desert lake margin: the mud-rich intervals 1 and 2 are sandy-mudflat deposits, characterized by high GR values. They were laid down when the desert-lake transgressed the lake-margin sandflats. The succession in between reflects progradation and subsequent retreat of a marginal dune field.

Well J06-A-03

Figure B3d:

Facies succession from the desert lake margin: the mud-rich intervals 1 and 2 are sandy-mudflat deposits, characterized by high GR values. They were laid down when the desert-lake transgressed the lake-margin sandflats. The succession in between reflects progradation and subsequent retreat of a marginal dune field.

Well J06-A-03

Figure B3e:

Well transect from roughly south (left) to north (right) of deposits representative for an “Ameland” equivalent time slice: proximal coarse-grained deposits from alluvial fan (Dwingelo-02: DWI-02) - coarse-grained braided-stream deposits at upper outwash plain (Annerveen-01: ANN-01) - medium-coarse-grained sandstones from dry-sandflat environment (Slochteren-04: SLO-04) fine grained, wavy laminated to irregular laminated sandstones interbedded with laminated to structureless claystone beds typical for deposition in a damp to wet sandflat environment in proximity of the playa lake (Uithuizermeeden-01A: UHM-01A and Ameland-Noord-01: AMN-01) - very fine-grained sheetflood deposits and wavy-laminated claystones of playa lake (Ameland Noord-01: AMN-01) - mixed halite and mud deposits representing deposition in short-lived perennial lake systems.

Figure B3e:

Well transect from roughly south (left) to north (right) of deposits representative for an “Ameland” equivalent time slice: proximal coarse-grained deposits from alluvial fan (Dwingelo-02: DWI-02) - coarse-grained braided-stream deposits at upper outwash plain (Annerveen-01: ANN-01) - medium-coarse-grained sandstones from dry-sandflat environment (Slochteren-04: SLO-04) fine grained, wavy laminated to irregular laminated sandstones interbedded with laminated to structureless claystone beds typical for deposition in a damp to wet sandflat environment in proximity of the playa lake (Uithuizermeeden-01A: UHM-01A and Ameland-Noord-01: AMN-01) - very fine-grained sheetflood deposits and wavy-laminated claystones of playa lake (Ameland Noord-01: AMN-01) - mixed halite and mud deposits representing deposition in short-lived perennial lake systems.

Lithofacies

Figure B4a:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. A crude textural lamination is visible (the dip is an apparent dip). Note the subtle imbrication towards the left of the larger elongated pebbles. This lithofacies is typical of a high-energy fluvial channel deposit as, for example, a braided channel.

Well Norg-05 (NOR-05)

Figure B4a:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. A crude textural lamination is visible (the dip is an apparent dip). Note the subtle imbrication towards the left of the larger elongated pebbles. This lithofacies is typical of a high-energy fluvial channel deposit as, for example, a braided channel.

Well Norg-05 (NOR-05)

Figure B4b:

Pebbly, coarse-grained sandstone. The majority of the pebbles are intraclasts. Especially, in the lower part of the core photograph large claystone intraclasts are present. Stratification is vaguely present, marked by subtle textural differences. This lithofacies is typical of relatively high-energy fluvial channel deposits cutting into adjacent floodplain.

Well Norg-04 (NOR-04)

Figure B4b:

Pebbly, coarse-grained sandstone. The majority of the pebbles are intraclasts. Especially, in the lower part of the core photograph large claystone intraclasts are present. Stratification is vaguely present, marked by subtle textural differences. This lithofacies is typical of relatively high-energy fluvial channel deposits cutting into adjacent floodplain.

Well Norg-04 (NOR-04)

Figure B4c:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. Crude textural lamination is visible (the dip is an apparent dip) of laminae with smaller and more elongate pebbles and laminae with a predominance of larger, spheroidal pebbles. Note the sharp boundary between the conglomerate and the underlying sandstone and the higher occurence of clay intraclasts at the base of the conglomerate. This lithofacies is typical of high-energy fluvial channel deposits, as for example a braided channel locally eroding floodplain-type deposits.

Well Norg-04 (NOR-04)

Figure B4c:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. Crude textural lamination is visible (the dip is an apparent dip) of laminae with smaller and more elongate pebbles and laminae with a predominance of larger, spheroidal pebbles. Note the sharp boundary between the conglomerate and the underlying sandstone and the higher occurence of clay intraclasts at the base of the conglomerate. This lithofacies is typical of high-energy fluvial channel deposits, as for example a braided channel locally eroding floodplain-type deposits.

Well Norg-04 (NOR-04)

Figure B4d:

Medium- to coarse-grained pebbly sandstone. Here the pebbles are mainly intraclasts, with some extraclasts present as well. The pale orange brown and grey patches are clay intraclasts, the white rounded to angular clasts are extraclasts. Compositional variation (high and low concentration of intraclasts crudely defines the bedding. Note the bedding-parallel orientation of the clasts, almost creating pseudolamination. This lithofacies is typical of a relative high energy fluvial channel eroding floodplain deposits.

Well Norg-05 (NOR-05)

Figure B4d:

Medium- to coarse-grained pebbly sandstone. Here the pebbles are mainly intraclasts, with some extraclasts present as well. The pale orange brown and grey patches are clay intraclasts, the white rounded to angular clasts are extraclasts. Compositional variation (high and low concentration of intraclasts crudely defines the bedding. Note the bedding-parallel orientation of the clasts, almost creating pseudolamination. This lithofacies is typical of a relative high energy fluvial channel eroding floodplain deposits.

Well Norg-05 (NOR-05)

Figure B4e:

A typical example of an intraclast conglomerate. Clasts are the erosional products from a mudflat environment through which a high-energy, sand-laden flood passed, ripping up the substratum. Note that some clasts appear to be imbricated.

Well K15-09

Figure B4e:

A typical example of an intraclast conglomerate. Clasts are the erosional products from a mudflat environment through which a high-energy, sand-laden flood passed, ripping up the substratum. Note that some clasts appear to be imbricated.

Well K15-09

Figure B4f:

Interbedded sandstone and intraformational conglomerate. The sandstone beds are horizontally laminated. The sandstone bed between 3435.80 m and 3435.50 m displays a fining-upward trend. Bed boundaries are gradual or undulating. It is remarkable that the conglomerate at 3435.45 m contains both claystone (dark coloured) and sandstone (light coloured) intraclasts. These lithofacies are interpreted as sheetflood deposits.

Well L13-15

Figure B4f:

Interbedded sandstone and intraformational conglomerate. The sandstone beds are horizontally laminated. The sandstone bed between 3435.80 m and 3435.50 m displays a fining-upward trend. Bed boundaries are gradual or undulating. It is remarkable that the conglomerate at 3435.45 m contains both claystone (dark coloured) and sandstone (light coloured) intraclasts. These lithofacies are interpreted as sheetflood deposits.

Well L13-15

Figure B4g:

Fine- to medium-grained sandstone with horizontal to low-angle stratification or lack of stratification. Rare intraclasts are present (e.g., at 4007.82 m and 4008.45 m). Subtle fining-upward trends can be seen. These facies are waterlaid (relatively high-energy) deposits. They may be the result of either confined (channeled) or unconfined sheetfloods.

Well K15-15A

Figure B4g:

Fine- to medium-grained sandstone with horizontal to low-angle stratification or lack of stratification. Rare intraclasts are present (e.g., at 4007.82 m and 4008.45 m). Subtle fining-upward trends can be seen. These facies are waterlaid (relatively high-energy) deposits. They may be the result of either confined (channeled) or unconfined sheetfloods.

Well K15-15A

Figure B4h:

Series of lithofacies consisting of yellowish grey, bimodal, very fine- and fine-grained sandstones with no detrital clay content and well rounded, frosted grains. It shows decimetre-to metre-scale cross stratification with foresets displaying alternations of normally to inversely graded laminae. Foreset dips vary between 22° and 30° resting on erosional bases. These deposits are typically found in dune toesets, aprons, and plinths.

Well Westbeemster-01 (WBMS-01)

Figure B4h:

Series of lithofacies consisting of yellowish grey, bimodal, very fine- and fine-grained sandstones with no detrital clay content and well rounded, frosted grains. It shows decimetre-to metre-scale cross stratification with foresets displaying alternations of normally to inversely graded laminae. Foreset dips vary between 22° and 30° resting on erosional bases. These deposits are typically found in dune toesets, aprons, and plinths.

Well Westbeemster-01 (WBMS-01)

Figure B4i:

Series of horizontally laminated greyish, bimodal, fine- to medium-grained sandstones, with some laminae clearly visible due to bitumen staining (note: the dip in the photo is an apparent dip). Single grain pinstripe laminae can be observed indicative of grainflow at the toe of slope of dune sets by lee-side eddies. Foresets resting on strongly erosional bases cutting into underlying deposits.

Well Norg-5 (NOR-05)

Figure B4i:

Series of horizontally laminated greyish, bimodal, fine- to medium-grained sandstones, with some laminae clearly visible due to bitumen staining (note: the dip in the photo is an apparent dip). Single grain pinstripe laminae can be observed indicative of grainflow at the toe of slope of dune sets by lee-side eddies. Foresets resting on strongly erosional bases cutting into underlying deposits.

Well Norg-5 (NOR-05)

Figure B4j:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed high-angle cross stratification. Planar stratification dominates, with top sets truncated by overlying beds. They range from slightly friable to consolidated with rare carbonate cement particularly at bed boundaries. These lithofacies were deposited as migrating aeolian dunes. Associated laminated and low-angle cross-bedded sandstones are attributed to deposition as dune bottomset or dry interdune sandsheet sediments.

Well Sauwerd-01 (SAU-01)

Figure B4j:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed high-angle cross stratification. Planar stratification dominates, with top sets truncated by overlying beds. They range from slightly friable to consolidated with rare carbonate cement particularly at bed boundaries. These lithofacies were deposited as migrating aeolian dunes. Associated laminated and low-angle cross-bedded sandstones are attributed to deposition as dune bottomset or dry interdune sandsheet sediments.

Well Sauwerd-01 (SAU-01)

Figure B4k:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed low-angle cross-stratification with increasing dip towards the top. Presence of erosional base of overlying horizontally laminated sandstone interpreted to represent bounding surface. These lithofacies were deposited as dune bottom sets or dry interdune sandsheet sediments.

Well Grijpskerk-01A (GRK-01A)

Figure B4k:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed low-angle cross-stratification with increasing dip towards the top. Presence of erosional base of overlying horizontally laminated sandstone interpreted to represent bounding surface. These lithofacies were deposited as dune bottom sets or dry interdune sandsheet sediments.

Well Grijpskerk-01A (GRK-01A)

Figure B4l:

Alternation of high-angle cross-bedded sandstones with intervals of horizontally laminated medium-grained sandstones. Boundaries of intervals representing bounding surfaces between lithofacies representing deposition in migrating dune bottomsets.

Well Grijpskerk-01A (GRK-01A)

Figure B4l:

Alternation of high-angle cross-bedded sandstones with intervals of horizontally laminated medium-grained sandstones. Boundaries of intervals representing bounding surfaces between lithofacies representing deposition in migrating dune bottomsets.

Well Grijpskerk-01A (GRK-01A)

Figure B4m:

Series of deposits characterised by presence of cross-laminated and ripple cross-laminated medium-coarse-grained sandstones. Pebble-size intraclasts present in the base of the bed at 3066.40 m are indicative for water-laid deposition under higher-energy fluvial conditions.

Well Norg-5 (NOR-05)

Figure B4m:

Series of deposits characterised by presence of cross-laminated and ripple cross-laminated medium-coarse-grained sandstones. Pebble-size intraclasts present in the base of the bed at 3066.40 m are indicative for water-laid deposition under higher-energy fluvial conditions.

Well Norg-5 (NOR-05)

Figure B4n:

Interval with horizontally to faintly wavy-laminated fine to medium-grained sandstones with layer composed of muddy rip-up clasts indicative of deposition in fluvial conditions. Upward gradual transition into yellowish massive unstructured fine to medium-grained sandstones interpreted to represent fluidised aeolian (dune?) lithofacies.

Well K17-07A

Figure B4n:

Interval with horizontally to faintly wavy-laminated fine to medium-grained sandstones with layer composed of muddy rip-up clasts indicative of deposition in fluvial conditions. Upward gradual transition into yellowish massive unstructured fine to medium-grained sandstones interpreted to represent fluidised aeolian (dune?) lithofacies.

Well K17-07A

Figure B4o:

Dry aeolian sandflat (interdune) to toeset of an aeolian dune: Horizontally laminated very fine to medium sand overlain by low-angle cross-stratified sand. Note the rapid changes in grain size from lamina to lamina, light-coloured very thin fine sand laminae from grain-fall cover thicker, darker, and coarser sand laminae (pinstripe lamination). Base of photo O shows underlying damp aeolian sandflat. The core interval indicates an intercalation of damp (Psah) and dry (Psay) aeolian sandflat deposits with only minor preservation of thin aeolian dune (Ad) beds in the Slochteren Formation.

Well Grijpskerk-01A (GRK-01A)

Figure B4o:

Dry aeolian sandflat (interdune) to toeset of an aeolian dune: Horizontally laminated very fine to medium sand overlain by low-angle cross-stratified sand. Note the rapid changes in grain size from lamina to lamina, light-coloured very thin fine sand laminae from grain-fall cover thicker, darker, and coarser sand laminae (pinstripe lamination). Base of photo O shows underlying damp aeolian sandflat. The core interval indicates an intercalation of damp (Psah) and dry (Psay) aeolian sandflat deposits with only minor preservation of thin aeolian dune (Ad) beds in the Slochteren Formation.

Well Grijpskerk-01A (GRK-01A)

Figure B4p:

Dry aeolian sandflat (Psay) with horizontally laminated fine to medium sand (photo P1). In photo P2 the horizontal lamination is interrupted by thin layers of contorted (cloudy) sand with whitish anhydrite or carbonate cementation, which formed from thin evaporitic crusts close to the sediment surface in a damp to wet sandflat environment. Dark colors of coarser-grained laminae are accentuated by black bitumen staining. The top of the core section shows the transition to an aeolian mudflat.

Well Kollumerpomp-01 (KMP-01)

Figure B4p:

Dry aeolian sandflat (Psay) with horizontally laminated fine to medium sand (photo P1). In photo P2 the horizontal lamination is interrupted by thin layers of contorted (cloudy) sand with whitish anhydrite or carbonate cementation, which formed from thin evaporitic crusts close to the sediment surface in a damp to wet sandflat environment. Dark colors of coarser-grained laminae are accentuated by black bitumen staining. The top of the core section shows the transition to an aeolian mudflat.

Well Kollumerpomp-01 (KMP-01)

Figure B4q:

Core section with top of a wettening-upward cycle in the Upper Slochteren Member. Sand, silt and clay in a patchy fabric (lower part of photo Q) formed by aeolian clastic transport in a damp sandflat with transient salt efflorescences. Evaporite minerals dissolved during subsequent flushing with undersaturated waters, leaving contorted clusters of different grain sizes in close vicinity. Note the large scatter of grain sizes in lower part of photo Q, and the upward increase of fine clastic material, eventually passing into an aeolian mudflat (Pma) at the top of photo Q. Within the mudflat fine clastics, clouds of sand are visible, indicating contortion and disruption of desiccating clay, with introduction of wind-blown sand.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B4q:

Core section with top of a wettening-upward cycle in the Upper Slochteren Member. Sand, silt and clay in a patchy fabric (lower part of photo Q) formed by aeolian clastic transport in a damp sandflat with transient salt efflorescences. Evaporite minerals dissolved during subsequent flushing with undersaturated waters, leaving contorted clusters of different grain sizes in close vicinity. Note the large scatter of grain sizes in lower part of photo Q, and the upward increase of fine clastic material, eventually passing into an aeolian mudflat (Pma) at the top of photo Q. Within the mudflat fine clastics, clouds of sand are visible, indicating contortion and disruption of desiccating clay, with introduction of wind-blown sand.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B4r:

"Wavy bedding" in fine- to medium grained sands in a damp (Psah) to wet aeolian sand-flat. Primary deposition occurred from catchment of aeolian sand on top of salt efflorescenses, which only partly dissolved later. The pale-coloured stripes and patches are remnants of formerly more complete evaporitic cementation (anhydrite, calcite), tracing irregularities of depositional surfaces (abrupt changes in grain size). White speckles indicate anhydritic (concretionary) cementation. Some laminae resemble adhesion-ripple layers. This kind of depositional facies and diagenetic overprint generally results in small disconnected patchy clusters of good porosity but overall poor reservoir quality.

Well Grijpskerk-01A (GRK-01A)

Figure B4r:

"Wavy bedding" in fine- to medium grained sands in a damp (Psah) to wet aeolian sand-flat. Primary deposition occurred from catchment of aeolian sand on top of salt efflorescenses, which only partly dissolved later. The pale-coloured stripes and patches are remnants of formerly more complete evaporitic cementation (anhydrite, calcite), tracing irregularities of depositional surfaces (abrupt changes in grain size). White speckles indicate anhydritic (concretionary) cementation. Some laminae resemble adhesion-ripple layers. This kind of depositional facies and diagenetic overprint generally results in small disconnected patchy clusters of good porosity but overall poor reservoir quality.

Well Grijpskerk-01A (GRK-01A)

Figure B4s:

Transition from a sheetflood sandstone (Fh) into suspension deposits of a pond (Bp), which was possibly formed by the same flood event (photo S). A desiccation crack filled with pale-coloured sand cuts down through both mud and sand. The crack-filling sand later carried formation waters that bleached the adjacent red mud interval. The core interval displays a relatively wet intercalation in a dominantly dry aeolian setting.

Well Grijpskerk-01A (GRK-01A)

Figure B4s:

Transition from a sheetflood sandstone (Fh) into suspension deposits of a pond (Bp), which was possibly formed by the same flood event (photo S). A desiccation crack filled with pale-coloured sand cuts down through both mud and sand. The crack-filling sand later carried formation waters that bleached the adjacent red mud interval. The core interval displays a relatively wet intercalation in a dominantly dry aeolian setting.

Well Grijpskerk-01A (GRK-01A)

Figure B4t:

Core interval presents a damp hydrological environment during Slochteren deposition with damp to wet aeolian sandflat (Psah, Psaw), sheetflood (Fh), and preserved pond (Bp) deposits. The lower 10 cm of photo T shows ripple laminated argillaceous sandstone forming the upper part of this sheetflod deposit, which is overlain by 15 cm deposits of a damp to wet evaporitic sandflat with grey (bleached) sandstones with white spots and patches of concretionary anhydrite or calcite cementation. Haloturbation has extensively modified primary depositional structures. The more muddy sediment towards the top of photo T has also been haloturbated and was less affected by bleaching.

Well Grijpskerk-01A (GRK-01A)

Figure B4t:

Core interval presents a damp hydrological environment during Slochteren deposition with damp to wet aeolian sandflat (Psah, Psaw), sheetflood (Fh), and preserved pond (Bp) deposits. The lower 10 cm of photo T shows ripple laminated argillaceous sandstone forming the upper part of this sheetflod deposit, which is overlain by 15 cm deposits of a damp to wet evaporitic sandflat with grey (bleached) sandstones with white spots and patches of concretionary anhydrite or calcite cementation. Haloturbation has extensively modified primary depositional structures. The more muddy sediment towards the top of photo T has also been haloturbated and was less affected by bleaching.

Well Grijpskerk-01A (GRK-01A)

Figure B4u:

The Slochteren sandstones in the Ameland area are located in a relatively distal position in the playa-margin area, which is the sandy coastal belt of the playa lake. The core section depicts a typical succession of facies from damp to wet aeolian sandflat (Psah, Psaw) to mudflat deposition (Pma). Haloturbation has obliterated most of the primary sedimentary structures in damp aeolian sandflat facies (photo U), but only minor amounts of evaporite cements (white speckles) have been preserved. The formerly red sand layers were bleached to gray colours during early hydrocarbon migration.

Well Ameland Oost-106 (AME-106)

Figure B4u:

The Slochteren sandstones in the Ameland area are located in a relatively distal position in the playa-margin area, which is the sandy coastal belt of the playa lake. The core section depicts a typical succession of facies from damp to wet aeolian sandflat (Psah, Psaw) to mudflat deposition (Pma). Haloturbation has obliterated most of the primary sedimentary structures in damp aeolian sandflat facies (photo U), but only minor amounts of evaporite cements (white speckles) have been preserved. The formerly red sand layers were bleached to gray colours during early hydrocarbon migration.

Well Ameland Oost-106 (AME-106)

Figure B4v:

The Annerveen field is located in a relatively proximal position south of the Groningen field. The core section shows a typical stacking of sandy to conglomeratic fluvial facies (Cfb), sheetflood (Fh), and ephemeral-pond deposits (Bp). Photo V illustrates lithotypes on top of a fining- upward interval with basal laminated clay and siltstone, deposited from flood events in ephemeral ponds, which desiccated and were subsequently covered by sheetflood (or wind-blown?) sand. The contortion of the thin sand layers was due to haloturbation (evaporation of saline groundwaters, expansive growth of evaporite minerals); a desiccation crack in a thin sand layer close to the top of photo V indicates less presence of salt water during cracking (early evaporite cementation would prevent shrinkage). The complex mixing of clay chips and pellets of different grain size is evidence that parts of the mudstones were redeposited by wind or water action.

Well Annerveen-01 (ANN-01)

Figure B4v:

The Annerveen field is located in a relatively proximal position south of the Groningen field. The core section shows a typical stacking of sandy to conglomeratic fluvial facies (Cfb), sheetflood (Fh), and ephemeral-pond deposits (Bp). Photo V illustrates lithotypes on top of a fining- upward interval with basal laminated clay and siltstone, deposited from flood events in ephemeral ponds, which desiccated and were subsequently covered by sheetflood (or wind-blown?) sand. The contortion of the thin sand layers was due to haloturbation (evaporation of saline groundwaters, expansive growth of evaporite minerals); a desiccation crack in a thin sand layer close to the top of photo V indicates less presence of salt water during cracking (early evaporite cementation would prevent shrinkage). The complex mixing of clay chips and pellets of different grain size is evidence that parts of the mudstones were redeposited by wind or water action.

Well Annerveen-01 (ANN-01)

Figure B4w:

Gamma-ray profile of Lower Slochteren Member (ROSLL) in offshore well K06-06, with core position close to the base of Rotliegend, above the Carboniferous Hospital Ground Formation (DCDG) (see Figure B1h, page 291). Distal reaches of fluvial sand, supplied by ephemeral flooding events, characterise the Rotliegend succession. Fine clastics from suspension were deposited on top of the bed-load sands in ephemeral ponds. Desiccation of these ponds is evidenced by cracks. Sand was transported from the south by ephemeral fluvial systems with source areas at the London Brabant Massif and adjacent Variscan highs. Close to the base of core photo W2 and near the top of photo W3, a patchy fabric of the sand indicates minor wind reworking and redeposition in thin damp-aeolian-sandflat intervals.

Well K06-06

Figure B4w:

Gamma-ray profile of Lower Slochteren Member (ROSLL) in offshore well K06-06, with core position close to the base of Rotliegend, above the Carboniferous Hospital Ground Formation (DCDG) (see Figure B1h, page 291). Distal reaches of fluvial sand, supplied by ephemeral flooding events, characterise the Rotliegend succession. Fine clastics from suspension were deposited on top of the bed-load sands in ephemeral ponds. Desiccation of these ponds is evidenced by cracks. Sand was transported from the south by ephemeral fluvial systems with source areas at the London Brabant Massif and adjacent Variscan highs. Close to the base of core photo W2 and near the top of photo W3, a patchy fabric of the sand indicates minor wind reworking and redeposition in thin damp-aeolian-sandflat intervals.

Well K06-06

Figure B4x:

Fluvial channel deposits (Cf) in the mudstone-dominated Ten Boer Member (Silverpit Formation). In photo X, mud-dominated playa deposits (Pmk), typical of the Ten Boer Member, display rippled aquatic sand transport (current or wave-ripple formation, M.S,x and S1l,x) with the mudstones either structureless, homogenized, or indistinctly laminated. The basal part of photo X shows a mudstone with disrupted fabric possibly due to aquatic reworking, including sandy matrix.

Well Norg-5 (NOR-05)

Figure B4x:

Fluvial channel deposits (Cf) in the mudstone-dominated Ten Boer Member (Silverpit Formation). In photo X, mud-dominated playa deposits (Pmk), typical of the Ten Boer Member, display rippled aquatic sand transport (current or wave-ripple formation, M.S,x and S1l,x) with the mudstones either structureless, homogenized, or indistinctly laminated. The basal part of photo X shows a mudstone with disrupted fabric possibly due to aquatic reworking, including sandy matrix.

Well Norg-5 (NOR-05)

Figure B4y:

Core section from well Grijpskerk-01A (GRK-01A), Grijpskerk UGS west of Groningen field. The core section demonstrates typical distal intercalation of sheetflood sand deposition (Fh) in a setting dominated by mudflat and lacustrine deposition (ponds Bp, wet aeolian sandflats Psaw, playa wet and evaporitic mudflats). Sheetflood suspension became ponded and deposited fines above the sand layers, depicted in photo Y. Sedimentary structures in the sand were overprinted by diagenetic processes including evaporite cementation, bleaching, and bitumen impregnation.

Well Grijpskerk-01A (GRK-01A)

Figure B4y:

Core section from well Grijpskerk-01A (GRK-01A), Grijpskerk UGS west of Groningen field. The core section demonstrates typical distal intercalation of sheetflood sand deposition (Fh) in a setting dominated by mudflat and lacustrine deposition (ponds Bp, wet aeolian sandflats Psaw, playa wet and evaporitic mudflats). Sheetflood suspension became ponded and deposited fines above the sand layers, depicted in photo Y. Sedimentary structures in the sand were overprinted by diagenetic processes including evaporite cementation, bleaching, and bitumen impregnation.

Well Grijpskerk-01A (GRK-01A)

Figure B4z:

Continuation of Figure B4y with distal sheetfloods in a mudflat setting. Photo Z shows mud-clast reworking during sand transport in sheetflood events. Only thin sand layers were accreted; slight contortion of both thin sand and mud layers can have formed from desiccation. Bleaching in sandstone layers and adjacent red clays and muds and bitumen impregnation indicate that interconnectedness of these thin sands, interrupted by clay partings, has been sufficient to allow hydrocarbon migration.

Well Grijpskerk-01A (GRK-01A)

Figure B4z:

Continuation of Figure B4y with distal sheetfloods in a mudflat setting. Photo Z shows mud-clast reworking during sand transport in sheetflood events. Only thin sand layers were accreted; slight contortion of both thin sand and mud layers can have formed from desiccation. Bleaching in sandstone layers and adjacent red clays and muds and bitumen impregnation indicate that interconnectedness of these thin sands, interrupted by clay partings, has been sufficient to allow hydrocarbon migration.

Well Grijpskerk-01A (GRK-01A)

Figure B4aa:

Wet aeolian sandflat deposits (Psaw) with siltstones and very fine-grained to fine-grained sandstones. Patchy sand fabric is typical in these facies with discontinuous irregular domains of silt and sand, sometimes with clusters of small clay flakes or pellets. Good to very good sorting of individual sand clusters is evidence for aeolian transport; deposition possibly occurred by adhesion on wet sticky surfaces or in the wind shadow of salt efflorescences. It is interpreted that disruption and contortion of the aeolian patches are caused by the dissolution of halitic efflorescences. Small nodules of white anhydrite are preserved in fine-grained intervals of photo AA1.

Well Ameland Oost-106 (AME-106)

Figure B4aa:

Wet aeolian sandflat deposits (Psaw) with siltstones and very fine-grained to fine-grained sandstones. Patchy sand fabric is typical in these facies with discontinuous irregular domains of silt and sand, sometimes with clusters of small clay flakes or pellets. Good to very good sorting of individual sand clusters is evidence for aeolian transport; deposition possibly occurred by adhesion on wet sticky surfaces or in the wind shadow of salt efflorescences. It is interpreted that disruption and contortion of the aeolian patches are caused by the dissolution of halitic efflorescences. Small nodules of white anhydrite are preserved in fine-grained intervals of photo AA1.

Well Ameland Oost-106 (AME-106)

Figure B4ab:

Transition of sandy mudstone from a wet sandflat (Psaw) into mudstone facies of a muddy playa to lacustrine system (Bb). The playa mudstones are macroscopically structureless, but can show microscopic mud-pellet texture. Wind-blown sand-sized clay particles accumulated as aeolian dunes (clay lunettes). An alternative mechanism forming the structureless appearance is multiple wetting and desiccation cycles of playa mud deposits. Small white anhydrite nodules are present in the lower, sandy part of the photo.

Well Bierum-13B (BIR-13B)

Figure B4ab:

Transition of sandy mudstone from a wet sandflat (Psaw) into mudstone facies of a muddy playa to lacustrine system (Bb). The playa mudstones are macroscopically structureless, but can show microscopic mud-pellet texture. Wind-blown sand-sized clay particles accumulated as aeolian dunes (clay lunettes). An alternative mechanism forming the structureless appearance is multiple wetting and desiccation cycles of playa mud deposits. Small white anhydrite nodules are present in the lower, sandy part of the photo.

Well Bierum-13B (BIR-13B)

Figure B4ac:

Example of a succession of aeolian mudflat deposits (Pma) with intercalations of lacustrine intervals (Bb, desert lake) and distal sheetflood sandstones (Fh). Patchy irregular fabric is dominant in aeolian muddy deposits with rapid changes in fine grain sizes from clay to coarse silt. On top of sheetflood sands the dark red claystones deposited from a shallow standing water body still show indistinct lamination which becomes contorted upward by desiccation and crack fills. Sandstones have horizontal lamination, sometimes with rippled tops.

Well K02-02

Figure B4ac:

Example of a succession of aeolian mudflat deposits (Pma) with intercalations of lacustrine intervals (Bb, desert lake) and distal sheetflood sandstones (Fh). Patchy irregular fabric is dominant in aeolian muddy deposits with rapid changes in fine grain sizes from clay to coarse silt. On top of sheetflood sands the dark red claystones deposited from a shallow standing water body still show indistinct lamination which becomes contorted upward by desiccation and crack fills. Sandstones have horizontal lamination, sometimes with rippled tops.

Well K02-02

Figure B4ad:

Mud-dominated halitic playa deposit (Pmk) above salt layer. The transition from discontinuous, more or less pure halite layers to mud can be gradual. Multiple phases of intrastratal halite dissolution and reprecipitation can lead to distinct boundaries between clays and muds and halite, giving it a brecciated appearance. Macroscopically no laminated clay is preserved from periods of aqueous clay deposition.

Well E09-01

Figure B4ad:

Mud-dominated halitic playa deposit (Pmk) above salt layer. The transition from discontinuous, more or less pure halite layers to mud can be gradual. Multiple phases of intrastratal halite dissolution and reprecipitation can lead to distinct boundaries between clays and muds and halite, giving it a brecciated appearance. Macroscopically no laminated clay is preserved from periods of aqueous clay deposition.

Well E09-01

Diagenesis

Figure B5a:

Partially bleached sandstone, Well Oosterwolde-01 (OWD-01). Thin section photo A: completely bleached white sandstone interval with high intergranular porosity; Thin section photo B: porous red sandstone interval with hematite coating on grain surfaces, ba = barite cement. Grey colours in the upper part of the core indicate bitumen impregnation after bleaching. Porosity in blue.

Well Oosterwolde-01 (OWD-01)

Figure B5a:

Partially bleached sandstone, Well Oosterwolde-01 (OWD-01). Thin section photo A: completely bleached white sandstone interval with high intergranular porosity; Thin section photo B: porous red sandstone interval with hematite coating on grain surfaces, ba = barite cement. Grey colours in the upper part of the core indicate bitumen impregnation after bleaching. Porosity in blue.

Well Oosterwolde-01 (OWD-01)

Figure B5b:

Wavy irregularly laminated sandstone of damp-aeolian-sand-flat facies (Psah). The sandstone is partially cemented with dolomite (whitel patches or laminae-like features), preserved as corroded rhombs (as in B1: dol) or blocky pore fills. After the grain-size (-layer) -selective dissolution of dolomite and precipitation of kaolinite booklets (k), bitumen impregnation resulted in the grey to dark grey color of the formerly red sandstone. Porosity in blue.

Well Grijpskerk-01A (GRK-01A)

Figure B5b:

Wavy irregularly laminated sandstone of damp-aeolian-sand-flat facies (Psah). The sandstone is partially cemented with dolomite (whitel patches or laminae-like features), preserved as corroded rhombs (as in B1: dol) or blocky pore fills. After the grain-size (-layer) -selective dissolution of dolomite and precipitation of kaolinite booklets (k), bitumen impregnation resulted in the grey to dark grey color of the formerly red sandstone. Porosity in blue.

Well Grijpskerk-01A (GRK-01A)

Figure B5c:

An example of partly homogenised and bleached aeolian sandstone (Weissliegend) below the black bituminous shales of the Coppershale Member (subenvironment Ba) in Well K15-15A. Thin section A1 with intergranular kaolinite (k) and siderite (s), A2 floating grains and domains of different intergranular volume, A3 leached anhydrite (an). Porosity in blue.

Well K15-15A

Figure B5c:

An example of partly homogenised and bleached aeolian sandstone (Weissliegend) below the black bituminous shales of the Coppershale Member (subenvironment Ba) in Well K15-15A. Thin section A1 with intergranular kaolinite (k) and siderite (s), A2 floating grains and domains of different intergranular volume, A3 leached anhydrite (an). Porosity in blue.

Well K15-15A

Figure B5d:

Whitish dolomite speckles in aeolian sandstone of Well Westbeemster-01 (WBMS-01). The pore space within the whitish speckles is completely occluded by (early) dolomite (thin section photomicrographs A1 and A2, cross-polarised light). The darker parts of the core show porosity created by the partial dissolution of dolomite.

Well Westbeemster-01 (WBMS-01)

Figure B5d:

Whitish dolomite speckles in aeolian sandstone of Well Westbeemster-01 (WBMS-01). The pore space within the whitish speckles is completely occluded by (early) dolomite (thin section photomicrographs A1 and A2, cross-polarised light). The darker parts of the core show porosity created by the partial dissolution of dolomite.

Well Westbeemster-01 (WBMS-01)

Figure B5e:

Bleached sandstone with dark streaks and patches due to the presence of bitumen, which appears as black pore-lining coats in thin-section photomicrographs A1, A2, and A3. Porosity in blue.

Well K15-09

Figure B5e:

Bleached sandstone with dark streaks and patches due to the presence of bitumen, which appears as black pore-lining coats in thin-section photomicrographs A1, A2, and A3. Porosity in blue.

Well K15-09

Figure B5f:

Extensive illite growth has reduced the reservoir quality (Phi = 15.1 %, Kh = 0.28 mD) of this bleached sandstone (photos A1 and A2, greenish-appearing meshwork illites on grain surfaces). The pore connectivity is severely reduced by delicate illite plates or fibers which span across pore throats (photo A2, arrows). Photo A3 shows the typical birefingence colour of illite cutans or coatings tangentially to grain surfaces under cross-polarised light. The minute and very thin illite plates in the meshworks are just visible under cross-polarised light here.

Well P02-09

Figure B5f:

Extensive illite growth has reduced the reservoir quality (Phi = 15.1 %, Kh = 0.28 mD) of this bleached sandstone (photos A1 and A2, greenish-appearing meshwork illites on grain surfaces). The pore connectivity is severely reduced by delicate illite plates or fibers which span across pore throats (photo A2, arrows). Photo A3 shows the typical birefingence colour of illite cutans or coatings tangentially to grain surfaces under cross-polarised light. The minute and very thin illite plates in the meshworks are just visible under cross-polarised light here.

Well P02-09

Figure B5g:

Partial bleaching of red reservoir sandstone along fracture in Well Hantum-01 (HTM-01). In photos A1 and A2 the relatively thick illite plates on grain surfaces show typical birefringence (arrows). In A2 kaolinite (k) (dickite?) booklets fill a pore after feldspar dissolution; kaolinite in adjacent pores is partly illitised. This extensive illitisation is typical of reservoirs close to major faults, here the Hantum fault, but also reservoirs adjacent to minor faults which are hydraulically linked to more prominent major faults can show intensive illitisation after dickite formation.

Well Hantum-01 (HTM-01)

Figure B5g:

Partial bleaching of red reservoir sandstone along fracture in Well Hantum-01 (HTM-01). In photos A1 and A2 the relatively thick illite plates on grain surfaces show typical birefringence (arrows). In A2 kaolinite (k) (dickite?) booklets fill a pore after feldspar dissolution; kaolinite in adjacent pores is partly illitised. This extensive illitisation is typical of reservoirs close to major faults, here the Hantum fault, but also reservoirs adjacent to minor faults which are hydraulically linked to more prominent major faults can show intensive illitisation after dickite formation.

Well Hantum-01 (HTM-01)

Figure B5h:

Red reservoir sandstone with hematite staining on grain surfaces. In photo A1 a large part of the intergranular volume is occupied by siderite (s) and kaolinite (k). The siderite is interpreted as a late diagenetic product that replaced earlier blocky cements (?dolomite) and detrital grains. Photo A2, which is a close-up of A1, shows kaolinite which probably replaced a grain or cement patch and which predates barite (ba). Photo A3 shows the same area as photo A1 under cross-polarised light. An orange tan on the core surface is the result of oxidation of abundant siderite (see base of core photo). Well K15-09, pores are blue in Photo A1 and A2.

Well K15-09

Figure B5h:

Red reservoir sandstone with hematite staining on grain surfaces. In photo A1 a large part of the intergranular volume is occupied by siderite (s) and kaolinite (k). The siderite is interpreted as a late diagenetic product that replaced earlier blocky cements (?dolomite) and detrital grains. Photo A2, which is a close-up of A1, shows kaolinite which probably replaced a grain or cement patch and which predates barite (ba). Photo A3 shows the same area as photo A1 under cross-polarised light. An orange tan on the core surface is the result of oxidation of abundant siderite (see base of core photo). Well K15-09, pores are blue in Photo A1 and A2.

Well K15-09

Faults and Fractures

Figure B6a:

Bleaching halo (arrows) around reactivated fracture. Dominant fracture fill is quartz, followed by clay forming dilational shears. Abundant clay content in the wallrock. Fractures are clustered and show both normal and reverse offsets (mm scale). Fractures are oblique and perpendicular to bedding.

Well K07-01

Figure B6a:

Bleaching halo (arrows) around reactivated fracture. Dominant fracture fill is quartz, followed by clay forming dilational shears. Abundant clay content in the wallrock. Fractures are clustered and show both normal and reverse offsets (mm scale). Fractures are oblique and perpendicular to bedding.

Well K07-01

Figure B6b:

Barite-cemented fracture (arrow). Extensive mineral growth occurred within and around the fracture.

Well K11-01

Figure B6b:

Barite-cemented fracture (arrow). Extensive mineral growth occurred within and around the fracture.

Well K11-01

Figure B6c:

Dilational shear fracture (cemented or partly cemented fracture with sliding and rolling of intact grains past each other by fracture dilation). A diagenetic halo is present resulting from hydrocarbon movement along the fracture. Microfaults with dominant reverse offsets (mm scale) are present. Bedding drag is visible below the plug position (arrow).

Well K11-01

Figure B6c:

Dilational shear fracture (cemented or partly cemented fracture with sliding and rolling of intact grains past each other by fracture dilation). A diagenetic halo is present resulting from hydrocarbon movement along the fracture. Microfaults with dominant reverse offsets (mm scale) are present. Bedding drag is visible below the plug position (arrow).

Well K11-01

Figure B6d:

An example of a complex fracture array (possibly cataclastic) with no visible offset. Fluid circulation (hydrocarbons?) caused a diagenetic (cement) halo around the fracture (arrow). Cataclastic processes and extensive mineral growth took place within and adjacent to the fracture during and soon after deformation.

Well K11-01

Figure B6d:

An example of a complex fracture array (possibly cataclastic) with no visible offset. Fluid circulation (hydrocarbons?) caused a diagenetic (cement) halo around the fracture (arrow). Cataclastic processes and extensive mineral growth took place within and adjacent to the fracture during and soon after deformation.

Well K11-01

Figure B6e:

Quartz-cemented fracture that terminates against thin shale streak (black arrow) and splays against harder cemented layer (blue arrow) at 3960.67 m.

Well K15-12

Figure B6e:

Quartz-cemented fracture that terminates against thin shale streak (black arrow) and splays against harder cemented layer (blue arrow) at 3960.67 m.

Well K15-12

Figure B6f:

Cataclastic fracture with some small offset visible (arrow).

Well K17-01

Figure B6f:

Cataclastic fracture with some small offset visible (arrow).

Well K17-01

Figure B6g:

Two phases of fractures. The first fracture phase is cataclastic (black arrow). The second phase of fracturing intersects the first cataclastic fractures and has resulted in partly open, partly cemented fractures. Iron staining is present near the intersection point (blue arrow). Clearly an example of differential cementation.

Well K17-01

Figure B6g:

Two phases of fractures. The first fracture phase is cataclastic (black arrow). The second phase of fracturing intersects the first cataclastic fractures and has resulted in partly open, partly cemented fractures. Iron staining is present near the intersection point (blue arrow). Clearly an example of differential cementation.

Well K17-01

Figure B6h:

An example of fracture arrestment. The cataclastic fracture is arrested by a thin cemented layer (arrow).

Well K17-01

Figure B6h:

An example of fracture arrestment. The cataclastic fracture is arrested by a thin cemented layer (arrow).

Well K17-01

Figure B6i:

A dilational, quartz-cemented fracture (black arrow) with offset of laminae (blue arrow).

Well K17-01

Figure B6i:

A dilational, quartz-cemented fracture (black arrow) with offset of laminae (blue arrow).

Well K17-01

Figure B6j:

An example of two generations of fractures which are intersecting and show complex fracture arrays.

Well K17-01

Figure B6j:

An example of two generations of fractures which are intersecting and show complex fracture arrays.

Well K17-01

Figure B6k:

An example of open and cemented fractures through conglomerates. Note that pebbles are split by the fractures (arrows). The tensile fractures are oriented subparallel to each other in an anastomosing pattern.

Well K17-01

Figure B6k:

An example of open and cemented fractures through conglomerates. Note that pebbles are split by the fractures (arrows). The tensile fractures are oriented subparallel to each other in an anastomosing pattern.

Well K17-01

Figure B6l:

An example of a cemented fracture with diagenetic halo (arrow).

Well K17-04

Figure B6l:

An example of a cemented fracture with diagenetic halo (arrow).

Well K17-04

Figure B6m:

Examples of cataclastic fractures.

Well K17-05

Figure B6m:

Examples of cataclastic fractures.

Well K17-05

Figure B6n:

A clay-filled and cemented fracture with a variable aperture and variable fill.

Well K17-05

Figure B6n:

A clay-filled and cemented fracture with a variable aperture and variable fill.

Well K17-05

Figure B6o:

Varying fracture densities due to geomechanical stratigraphy in a core in the overlying Zechstein 3 Carbonate (ZEZ3C) interval. Bed-constrained fracture growth is indicated by red arrows. Both open (black arrows) and closed, cemented (blue arrows) fractures are present. Fracture cements consist of anhydrite and dolomite.

Well K17-08

Figure B6o:

Varying fracture densities due to geomechanical stratigraphy in a core in the overlying Zechstein 3 Carbonate (ZEZ3C) interval. Bed-constrained fracture growth is indicated by red arrows. Both open (black arrows) and closed, cemented (blue arrows) fractures are present. Fracture cements consist of anhydrite and dolomite.

Well K17-08

Figure B6p:

A cemented fracture with offset of beds (arrow) and a small fault with a brecciated and cemented fill (B).

Well K17-08

Figure B6p:

A cemented fracture with offset of beds (arrow) and a small fault with a brecciated and cemented fill (B).

Well K17-08

Figure B6q:

An example from Triassic strata of an anhydrite-cemented fracture showing a step-over at a harder cemented layer (arrow).

Well L09-08

Figure B6q:

An example from Triassic strata of an anhydrite-cemented fracture showing a step-over at a harder cemented layer (arrow).

Well L09-08

Figure B6r:

The figure illustrates heterogeneity of fracture fill encountered in the Rotliegend. The example shows a clay and cement-filled fracture with very variable aperture (black arrow). Also open fractures, partially filled with anhydrite cement (blue arrow) are present.

Well L13-15

Figure B6r:

The figure illustrates heterogeneity of fracture fill encountered in the Rotliegend. The example shows a clay and cement-filled fracture with very variable aperture (black arrow). Also open fractures, partially filled with anhydrite cement (blue arrow) are present.

Well L13-15

Figure B6s:

The figure shows what is interpreted as a small fault, with clay pebbles and clay flakes in the fault gouge.

Well L13-15

Figure B6s:

The figure shows what is interpreted as a small fault, with clay pebbles and clay flakes in the fault gouge.

Well L13-15

Figure B6t:

A cemented halo at dip fracture (blue box), a clay-filled cemented fracture (blue arrow) and a cemented fracture with small offset (black arrow).

Well L13-15

Figure B6t:

A cemented halo at dip fracture (blue box), a clay-filled cemented fracture (blue arrow) and a cemented fracture with small offset (black arrow).

Well L13-15

Figure B6u:

An example of a clay- and cement-filled fracture. The clay-filled fracture in the lower part of the image seems to splay towards the bottom (arrow).

Well L13-15

Figure B6u:

An example of a clay- and cement-filled fracture. The clay-filled fracture in the lower part of the image seems to splay towards the bottom (arrow).

Well L13-15

Figure B6v:

A partly open and partly closed fracture with diagenetic halo. Bleaching of the sediment is considered to have been caused by ingress of fluids (hydrocarbons and/or CO2) with tectonic activity.

Well L13-FC-101

Figure B6v:

A partly open and partly closed fracture with diagenetic halo. Bleaching of the sediment is considered to have been caused by ingress of fluids (hydrocarbons and/or CO2) with tectonic activity.

Well L13-FC-101

Figure B6w:

An example of multiple phases of fracturing.

Well Norg-4 (NOR-04)

Figure B6w:

An example of multiple phases of fracturing.

Well Norg-4 (NOR-04)

Figure B6x:

A fractured and brecciated zone.

Well Norg-4 (NOR-04)

Figure B6x:

A fractured and brecciated zone.

Well Norg-4 (NOR-04)

Figure B6y:

A fracture zone with intersecting partly open fractures.

Well Norg-4 (NOR-04)

Figure B6y:

A fracture zone with intersecting partly open fractures.

Well Norg-4 (NOR-04)

Figures & Tables

Figure B1a:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale is the black claystone interval between 2517.28 and 2517.58 m with a very sharp base. Below the Coppershale the Ten Boer Member is present comprising a series of interbedded claystones and fine to very fine sandstones. Note the bleaching of the sandstone bed directly underneath the Coppershale and the reduction spots around sandier patches at 2518.45 m. See Figure B5c for another example of bleached sandstone directly below the Coppershale.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B1a:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale is the black claystone interval between 2517.28 and 2517.58 m with a very sharp base. Below the Coppershale the Ten Boer Member is present comprising a series of interbedded claystones and fine to very fine sandstones. Note the bleaching of the sandstone bed directly underneath the Coppershale and the reduction spots around sandier patches at 2518.45 m. See Figure B5c for another example of bleached sandstone directly below the Coppershale.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B1b:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale in this well is the thin black claystone bed between 2663.76 and 2663.84 m. Below the Coppershale the Ten Boer Member is present in this well. The Ten Boer is characterized by interbedded claystones and fine to very fine sandstones which are structureless or have lenticular lamination and disturbed lamination and even show signs of rootlets. Note the color change from grey to reddish at the boundary of mudflat to wet sandflat sediments at 2664.75 m.

Well Slochteren-04 (SLO-04)

Figure B1b:

The top of the Upper Rotliegend Group is picked at the base of the Coppershale (Zechstein Group). The Coppershale in this well is the thin black claystone bed between 2663.76 and 2663.84 m. Below the Coppershale the Ten Boer Member is present in this well. The Ten Boer is characterized by interbedded claystones and fine to very fine sandstones which are structureless or have lenticular lamination and disturbed lamination and even show signs of rootlets. Note the color change from grey to reddish at the boundary of mudflat to wet sandflat sediments at 2664.75 m.

Well Slochteren-04 (SLO-04)

Figure B1c:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous sandstone. In this well the BPU was previously picked at 3579.26 m, at the base of a thick section of conglomerates and some sandstones. These overly a mature, red soil which is classified as Carboniferous. The conglomerate section is characterised by its red colour, mouldic porosity, absence of “sedimentary” clasts, and numerous erosional bed boundaries. It is overlain by a red claystone with typical Rotliegend Silverpit character. At the very base of this claystone on top of the sandstone of the conglomeratic section a thin conglomeratic bed of a few centimeters thickness is present, comprising sandstone clasts. Sandstone clasts are not observed in the conglomeratic section. In combination with palynological and geochemical analyses these observations point towards an updated position of the BPU picked at 3975.70 m.

Well K02-02

Figure B1c:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous sandstone. In this well the BPU was previously picked at 3579.26 m, at the base of a thick section of conglomerates and some sandstones. These overly a mature, red soil which is classified as Carboniferous. The conglomerate section is characterised by its red colour, mouldic porosity, absence of “sedimentary” clasts, and numerous erosional bed boundaries. It is overlain by a red claystone with typical Rotliegend Silverpit character. At the very base of this claystone on top of the sandstone of the conglomeratic section a thin conglomeratic bed of a few centimeters thickness is present, comprising sandstone clasts. Sandstone clasts are not observed in the conglomeratic section. In combination with palynological and geochemical analyses these observations point towards an updated position of the BPU picked at 3975.70 m.

Well K02-02

Figure B1d:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous claystone. The BPU in this well is picked at the change in lithology from Carboniferous (reddish) grey claystone to primarily coarse clastic deposits of the Rotliegend. The Carboniferous claystones are contorted to structureless with some rootlet traces. The conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Annen-Anlo-01 (ANL-01)

Figure B1d:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous claystone. The BPU in this well is picked at the change in lithology from Carboniferous (reddish) grey claystone to primarily coarse clastic deposits of the Rotliegend. The Carboniferous claystones are contorted to structureless with some rootlet traces. The conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Annen-Anlo-01 (ANL-01)

Figure B1e:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous sandstone. The BPU in this well is picked at the change in lithology from Carboniferous grey, fine-grained sandstone to the red conglomerate of the Rotliegend. The Carboniferous sandstone shows fine horizontal lamination to ripple lamination which is lightly contorted. The massive conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Slochteren-04 (SLO-04)

Figure B1e:

The Base Permian Unconformity (BPU): Rotliegend conglomerate on Carboniferous sandstone. The BPU in this well is picked at the change in lithology from Carboniferous grey, fine-grained sandstone to the red conglomerate of the Rotliegend. The Carboniferous sandstone shows fine horizontal lamination to ripple lamination which is lightly contorted. The massive conglomerate comprises predominantly well-rounded extraclasts and shows some crude lamination.

Well Slochteren-04 (SLO-04)

Figure B1f:

The Base Permian Unconformity (BPU): Rotliegend interbedded sandstone and claystone on Carboniferous claystone. The BPU in this well is picked at the change in lithology and colour from Carboniferous, grey claystone to red to light grey claystones and sandstones at 3466.03 m. The Carboniferous claystone is structureless to vaguely laminated and shows red oxidation spots and streaks. The Rotliegend claystones instead are typically brick red whereas the coarser-grained sandier intervals are whitish grey.

Well Norg-04 (NOR-04)

Figure B1f:

The Base Permian Unconformity (BPU): Rotliegend interbedded sandstone and claystone on Carboniferous claystone. The BPU in this well is picked at the change in lithology and colour from Carboniferous, grey claystone to red to light grey claystones and sandstones at 3466.03 m. The Carboniferous claystone is structureless to vaguely laminated and shows red oxidation spots and streaks. The Rotliegend claystones instead are typically brick red whereas the coarser-grained sandier intervals are whitish grey.

Well Norg-04 (NOR-04)

Figure B1g:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous claystone. In this well the BPU was picked at 3829 m LD = 3822.3 m DD at the base of a relatively thin sandstone interval which has just been cored (core to log shift approximately 6.5 m). However, inspecting the underlying red claystone interval more closely, a subtle change in texture and colour can be seen some 7 m below the sandstone. It grades downward from the typical brick red homogeneous to vaguely laminated Silverpit-like claystone to a slightly more purple distorted claystone. The former claystone can be attributed to the Rotliegend Hollum Member. Petrographical (Gokdag and van den Heuvel 1983 see well file G18-1 on www.nlog.nl) and preliminary results of biostratigraphical research suggest that this may well be the case. Therefore, an alternative BPU location is at approximately 3829.4 m.

Well G18-01

Figure B1g:

The Base Permian Unconformity (BPU): Rotliegend claystone on Carboniferous claystone. In this well the BPU was picked at 3829 m LD = 3822.3 m DD at the base of a relatively thin sandstone interval which has just been cored (core to log shift approximately 6.5 m). However, inspecting the underlying red claystone interval more closely, a subtle change in texture and colour can be seen some 7 m below the sandstone. It grades downward from the typical brick red homogeneous to vaguely laminated Silverpit-like claystone to a slightly more purple distorted claystone. The former claystone can be attributed to the Rotliegend Hollum Member. Petrographical (Gokdag and van den Heuvel 1983 see well file G18-1 on www.nlog.nl) and preliminary results of biostratigraphical research suggest that this may well be the case. Therefore, an alternative BPU location is at approximately 3829.4 m.

Well G18-01

Figure B1h:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The issue here is the position of the BPU, which cannot be clearly resolved and is therefore questionable. On the operator′s composite log (ref. www.nlog.nl) the BPU is picked @ 3840.5 m (LD). An alternative location of the BPU based on core evaluation is @ 3828.2 m DD. After core to log-shift the BPU is set @ 3835.0 m LD. Arguments for assigning the interval 3835-3840 m LD to the Carboniferous are the combination of colour, sedimentary structures, hematite cementation, presence of mouldic porosity and the occurence of a thin, basal conglomeratic lag comprising clasts from the underlying sandstone.

Well K06-06

Figure B1h:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The issue here is the position of the BPU, which cannot be clearly resolved and is therefore questionable. On the operator′s composite log (ref. www.nlog.nl) the BPU is picked @ 3840.5 m (LD). An alternative location of the BPU based on core evaluation is @ 3828.2 m DD. After core to log-shift the BPU is set @ 3835.0 m LD. Arguments for assigning the interval 3835-3840 m LD to the Carboniferous are the combination of colour, sedimentary structures, hematite cementation, presence of mouldic porosity and the occurence of a thin, basal conglomeratic lag comprising clasts from the underlying sandstone.

Well K06-06

Figure B1i:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The BPU is picked within a sandstone unit at the base of a pebbly sandstone bed which ovelies a fractured sandstone. The fractures appear to be truncated by the pebbly sandstone.

Well J06-A-05

Figure B1i:

The Base Permian Unconformity (BPU): Rotliegend sandstone on Carboniferous sandstone. The BPU is picked within a sandstone unit at the base of a pebbly sandstone bed which ovelies a fractured sandstone. The fractures appear to be truncated by the pebbly sandstone.

Well J06-A-05

Figure B2a:

Sharp transition at 2708.5 m from grey fine-grained homogenised sandstones deposited as ephemeral, high-energy fluvial sediment of Upper Slochteren Member to overlying red-brown wavy-bedded claystones deposited in poorly drained mud and sandflat environments in the proximity of the perennial lake classified as the Ten Boer Member. This transition probably marks the onset of a regional rise of base level and expansion of the desert lake and can be confidently correlated to other wells in the area.

Well Slochteren-04 (SLO-04)

Figure B2a:

Sharp transition at 2708.5 m from grey fine-grained homogenised sandstones deposited as ephemeral, high-energy fluvial sediment of Upper Slochteren Member to overlying red-brown wavy-bedded claystones deposited in poorly drained mud and sandflat environments in the proximity of the perennial lake classified as the Ten Boer Member. This transition probably marks the onset of a regional rise of base level and expansion of the desert lake and can be confidently correlated to other wells in the area.

Well Slochteren-04 (SLO-04)

Figure B2b:

Gradually upwards-fining trend from medium-coarse-grained fluvial sandstones through a series of fine-grained, wavy-bedded muddy sandstones and finally to red to reddish brown horizontally laminated claystones deposited in a mudflat environment on the margin of a playa-lake. This is indicative of a more subtle expansion of the playa lake (Ten Boer Member) at the expense of gradually backstepping fluvial systems of the Upper Slochteren Member.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B2b:

Gradually upwards-fining trend from medium-coarse-grained fluvial sandstones through a series of fine-grained, wavy-bedded muddy sandstones and finally to red to reddish brown horizontally laminated claystones deposited in a mudflat environment on the margin of a playa-lake. This is indicative of a more subtle expansion of the playa lake (Ten Boer Member) at the expense of gradually backstepping fluvial systems of the Upper Slochteren Member.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B2c:

Center of basin during Silverpit Formation. Upper part of Silverpit Evaporite Member, basal section of a ca.10-m-thick halite-rich interval. Red claystone intermixed with halite crystal clusters in a brecciated fabric indicate an evaporite precipitation in a playa salt pan to evaporitic mudflat with frequent flooding and desiccation events. Brecciation is interpreted to be due to haloturbation and frequent changes of salt-ridge growth and partial dissolution of the interstitial evaporitic material. Layer of colourless to reddish compact halite has sharp and irregular boundaries to overlying and underlying brecciated halitic clay, which also contains nodules of anhydrite (subaerial pedogenic origin). Evidence for a perennial lacustrine standing water body such as laminated clay is absent.

Well E09-01

Figure B2c:

Center of basin during Silverpit Formation. Upper part of Silverpit Evaporite Member, basal section of a ca.10-m-thick halite-rich interval. Red claystone intermixed with halite crystal clusters in a brecciated fabric indicate an evaporite precipitation in a playa salt pan to evaporitic mudflat with frequent flooding and desiccation events. Brecciation is interpreted to be due to haloturbation and frequent changes of salt-ridge growth and partial dissolution of the interstitial evaporitic material. Layer of colourless to reddish compact halite has sharp and irregular boundaries to overlying and underlying brecciated halitic clay, which also contains nodules of anhydrite (subaerial pedogenic origin). Evidence for a perennial lacustrine standing water body such as laminated clay is absent.

Well E09-01

Figure B2d

Boundary between Slochteren Formation and the Silverpit Formation This is a relatively subjective lithostratigraphic boundary (reference Van Adrichem Boogaert et al 1993) because it is a gradual boundary from a sandstone-rich to a claystone-rich sediment series Here it is picked at , the top of the last definite sandstone bed occurring at 3954 m

Well K02-02

Figure B2d

Boundary between Slochteren Formation and the Silverpit Formation This is a relatively subjective lithostratigraphic boundary (reference Van Adrichem Boogaert et al 1993) because it is a gradual boundary from a sandstone-rich to a claystone-rich sediment series Here it is picked at , the top of the last definite sandstone bed occurring at 3954 m

Well K02-02

Figure B2e:

Boundary between the Hollum Member (Silverpit Formation) and the Lower Slochteren Member (Slochteren Formation). This is a quite sharp boundary picked at the base of the first prominent sandstone bed from the clay-prone Hollum Member at 3961.83 m. The Hollum Member predominantly comprises massive, red claystones but towards the top interbedded silt and fine-grained sandstone beds are more common.

Well K02-02

Figure B2e:

Boundary between the Hollum Member (Silverpit Formation) and the Lower Slochteren Member (Slochteren Formation). This is a quite sharp boundary picked at the base of the first prominent sandstone bed from the clay-prone Hollum Member at 3961.83 m. The Hollum Member predominantly comprises massive, red claystones but towards the top interbedded silt and fine-grained sandstone beds are more common.

Well K02-02

Figure B3a:

Example of lithofacies interpreted as being produced in desert environment as dune slipface deposits with coarser strata formed by avalanching of loose sand down the slipface, alternating with grain-fall laminae produced by deposition of fine-grained sand out of suspension. The predominance of normal grading, grain-fall strata, and compressional soft-sediment deformation structures suggest that only lower parts of dune foresets are preserved. The presence of multiple reactivation or bounding surfaces suggests changes in wind character. These sediments and their interpreted depositional environment are typical of the Slochteren Formation present at the Mid Netherlands High area representing an erg located on the lee side of a major fluvial trunk system in the East.

Well Westbeemster-01 (WBMS-01)

Figure B3a:

Example of lithofacies interpreted as being produced in desert environment as dune slipface deposits with coarser strata formed by avalanching of loose sand down the slipface, alternating with grain-fall laminae produced by deposition of fine-grained sand out of suspension. The predominance of normal grading, grain-fall strata, and compressional soft-sediment deformation structures suggest that only lower parts of dune foresets are preserved. The presence of multiple reactivation or bounding surfaces suggests changes in wind character. These sediments and their interpreted depositional environment are typical of the Slochteren Formation present at the Mid Netherlands High area representing an erg located on the lee side of a major fluvial trunk system in the East.

Well Westbeemster-01 (WBMS-01)

Figure B3b:

These sediments reflect deposition in a braided-stream and (upper) outwash-plain environment closely linked to the southern boundary of the Southern Permian Basin. This (repetitive) specific pattern of environments and their constituent sediments can be related to phases of hinterland uplift alternating with phases of basin fill. Uplift caused the spread of sheets of high-energy braided streams northwestwards passing laterally to thick blankets of sheetflood-deposited sandstones.

Well Slochteren-04 (SLO-04)

Figure B3b:

These sediments reflect deposition in a braided-stream and (upper) outwash-plain environment closely linked to the southern boundary of the Southern Permian Basin. This (repetitive) specific pattern of environments and their constituent sediments can be related to phases of hinterland uplift alternating with phases of basin fill. Uplift caused the spread of sheets of high-energy braided streams northwestwards passing laterally to thick blankets of sheetflood-deposited sandstones.

Well Slochteren-04 (SLO-04)

Figure B3c:

The photo shows the quite abrupt upwards change from a cross-stratified, fine–medium grained sandstone (S3l,xh) to a fine–medium grained adhesion-ripple sandstone showing vague horizontal (S2u,l) to wavy lamination and with a low detrital clay content. The cross-stratified sandstone is interpreted as an aeolian dune deposit whereas the wavy-bedded sandstone is interpreted to be deposited on a dry aeolian sandflat.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B3c:

The photo shows the quite abrupt upwards change from a cross-stratified, fine–medium grained sandstone (S3l,xh) to a fine–medium grained adhesion-ripple sandstone showing vague horizontal (S2u,l) to wavy lamination and with a low detrital clay content. The cross-stratified sandstone is interpreted as an aeolian dune deposit whereas the wavy-bedded sandstone is interpreted to be deposited on a dry aeolian sandflat.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B3d:

Facies succession from the desert lake margin: the mud-rich intervals 1 and 2 are sandy-mudflat deposits, characterized by high GR values. They were laid down when the desert-lake transgressed the lake-margin sandflats. The succession in between reflects progradation and subsequent retreat of a marginal dune field.

Well J06-A-03

Figure B3d:

Facies succession from the desert lake margin: the mud-rich intervals 1 and 2 are sandy-mudflat deposits, characterized by high GR values. They were laid down when the desert-lake transgressed the lake-margin sandflats. The succession in between reflects progradation and subsequent retreat of a marginal dune field.

Well J06-A-03

Figure B3e:

Well transect from roughly south (left) to north (right) of deposits representative for an “Ameland” equivalent time slice: proximal coarse-grained deposits from alluvial fan (Dwingelo-02: DWI-02) - coarse-grained braided-stream deposits at upper outwash plain (Annerveen-01: ANN-01) - medium-coarse-grained sandstones from dry-sandflat environment (Slochteren-04: SLO-04) fine grained, wavy laminated to irregular laminated sandstones interbedded with laminated to structureless claystone beds typical for deposition in a damp to wet sandflat environment in proximity of the playa lake (Uithuizermeeden-01A: UHM-01A and Ameland-Noord-01: AMN-01) - very fine-grained sheetflood deposits and wavy-laminated claystones of playa lake (Ameland Noord-01: AMN-01) - mixed halite and mud deposits representing deposition in short-lived perennial lake systems.

Figure B3e:

Well transect from roughly south (left) to north (right) of deposits representative for an “Ameland” equivalent time slice: proximal coarse-grained deposits from alluvial fan (Dwingelo-02: DWI-02) - coarse-grained braided-stream deposits at upper outwash plain (Annerveen-01: ANN-01) - medium-coarse-grained sandstones from dry-sandflat environment (Slochteren-04: SLO-04) fine grained, wavy laminated to irregular laminated sandstones interbedded with laminated to structureless claystone beds typical for deposition in a damp to wet sandflat environment in proximity of the playa lake (Uithuizermeeden-01A: UHM-01A and Ameland-Noord-01: AMN-01) - very fine-grained sheetflood deposits and wavy-laminated claystones of playa lake (Ameland Noord-01: AMN-01) - mixed halite and mud deposits representing deposition in short-lived perennial lake systems.

Figure B4a:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. A crude textural lamination is visible (the dip is an apparent dip). Note the subtle imbrication towards the left of the larger elongated pebbles. This lithofacies is typical of a high-energy fluvial channel deposit as, for example, a braided channel.

Well Norg-05 (NOR-05)

Figure B4a:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. A crude textural lamination is visible (the dip is an apparent dip). Note the subtle imbrication towards the left of the larger elongated pebbles. This lithofacies is typical of a high-energy fluvial channel deposit as, for example, a braided channel.

Well Norg-05 (NOR-05)

Figure B4b:

Pebbly, coarse-grained sandstone. The majority of the pebbles are intraclasts. Especially, in the lower part of the core photograph large claystone intraclasts are present. Stratification is vaguely present, marked by subtle textural differences. This lithofacies is typical of relatively high-energy fluvial channel deposits cutting into adjacent floodplain.

Well Norg-04 (NOR-04)

Figure B4b:

Pebbly, coarse-grained sandstone. The majority of the pebbles are intraclasts. Especially, in the lower part of the core photograph large claystone intraclasts are present. Stratification is vaguely present, marked by subtle textural differences. This lithofacies is typical of relatively high-energy fluvial channel deposits cutting into adjacent floodplain.

Well Norg-04 (NOR-04)

Figure B4c:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. Crude textural lamination is visible (the dip is an apparent dip) of laminae with smaller and more elongate pebbles and laminae with a predominance of larger, spheroidal pebbles. Note the sharp boundary between the conglomerate and the underlying sandstone and the higher occurence of clay intraclasts at the base of the conglomerate. This lithofacies is typical of high-energy fluvial channel deposits, as for example a braided channel locally eroding floodplain-type deposits.

Well Norg-04 (NOR-04)

Figure B4c:

Typical pebble-size conglomerate of the Slochteren Formation. It comprises predominantly well-rounded extraclasts and subordinate intraclasts. Crude textural lamination is visible (the dip is an apparent dip) of laminae with smaller and more elongate pebbles and laminae with a predominance of larger, spheroidal pebbles. Note the sharp boundary between the conglomerate and the underlying sandstone and the higher occurence of clay intraclasts at the base of the conglomerate. This lithofacies is typical of high-energy fluvial channel deposits, as for example a braided channel locally eroding floodplain-type deposits.

Well Norg-04 (NOR-04)

Figure B4d:

Medium- to coarse-grained pebbly sandstone. Here the pebbles are mainly intraclasts, with some extraclasts present as well. The pale orange brown and grey patches are clay intraclasts, the white rounded to angular clasts are extraclasts. Compositional variation (high and low concentration of intraclasts crudely defines the bedding. Note the bedding-parallel orientation of the clasts, almost creating pseudolamination. This lithofacies is typical of a relative high energy fluvial channel eroding floodplain deposits.

Well Norg-05 (NOR-05)

Figure B4d:

Medium- to coarse-grained pebbly sandstone. Here the pebbles are mainly intraclasts, with some extraclasts present as well. The pale orange brown and grey patches are clay intraclasts, the white rounded to angular clasts are extraclasts. Compositional variation (high and low concentration of intraclasts crudely defines the bedding. Note the bedding-parallel orientation of the clasts, almost creating pseudolamination. This lithofacies is typical of a relative high energy fluvial channel eroding floodplain deposits.

Well Norg-05 (NOR-05)

Figure B4e:

A typical example of an intraclast conglomerate. Clasts are the erosional products from a mudflat environment through which a high-energy, sand-laden flood passed, ripping up the substratum. Note that some clasts appear to be imbricated.

Well K15-09

Figure B4e:

A typical example of an intraclast conglomerate. Clasts are the erosional products from a mudflat environment through which a high-energy, sand-laden flood passed, ripping up the substratum. Note that some clasts appear to be imbricated.

Well K15-09

Figure B4f:

Interbedded sandstone and intraformational conglomerate. The sandstone beds are horizontally laminated. The sandstone bed between 3435.80 m and 3435.50 m displays a fining-upward trend. Bed boundaries are gradual or undulating. It is remarkable that the conglomerate at 3435.45 m contains both claystone (dark coloured) and sandstone (light coloured) intraclasts. These lithofacies are interpreted as sheetflood deposits.

Well L13-15

Figure B4f:

Interbedded sandstone and intraformational conglomerate. The sandstone beds are horizontally laminated. The sandstone bed between 3435.80 m and 3435.50 m displays a fining-upward trend. Bed boundaries are gradual or undulating. It is remarkable that the conglomerate at 3435.45 m contains both claystone (dark coloured) and sandstone (light coloured) intraclasts. These lithofacies are interpreted as sheetflood deposits.

Well L13-15

Figure B4g:

Fine- to medium-grained sandstone with horizontal to low-angle stratification or lack of stratification. Rare intraclasts are present (e.g., at 4007.82 m and 4008.45 m). Subtle fining-upward trends can be seen. These facies are waterlaid (relatively high-energy) deposits. They may be the result of either confined (channeled) or unconfined sheetfloods.

Well K15-15A

Figure B4g:

Fine- to medium-grained sandstone with horizontal to low-angle stratification or lack of stratification. Rare intraclasts are present (e.g., at 4007.82 m and 4008.45 m). Subtle fining-upward trends can be seen. These facies are waterlaid (relatively high-energy) deposits. They may be the result of either confined (channeled) or unconfined sheetfloods.

Well K15-15A

Figure B4h:

Series of lithofacies consisting of yellowish grey, bimodal, very fine- and fine-grained sandstones with no detrital clay content and well rounded, frosted grains. It shows decimetre-to metre-scale cross stratification with foresets displaying alternations of normally to inversely graded laminae. Foreset dips vary between 22° and 30° resting on erosional bases. These deposits are typically found in dune toesets, aprons, and plinths.

Well Westbeemster-01 (WBMS-01)

Figure B4h:

Series of lithofacies consisting of yellowish grey, bimodal, very fine- and fine-grained sandstones with no detrital clay content and well rounded, frosted grains. It shows decimetre-to metre-scale cross stratification with foresets displaying alternations of normally to inversely graded laminae. Foreset dips vary between 22° and 30° resting on erosional bases. These deposits are typically found in dune toesets, aprons, and plinths.

Well Westbeemster-01 (WBMS-01)

Figure B4i:

Series of horizontally laminated greyish, bimodal, fine- to medium-grained sandstones, with some laminae clearly visible due to bitumen staining (note: the dip in the photo is an apparent dip). Single grain pinstripe laminae can be observed indicative of grainflow at the toe of slope of dune sets by lee-side eddies. Foresets resting on strongly erosional bases cutting into underlying deposits.

Well Norg-5 (NOR-05)

Figure B4i:

Series of horizontally laminated greyish, bimodal, fine- to medium-grained sandstones, with some laminae clearly visible due to bitumen staining (note: the dip in the photo is an apparent dip). Single grain pinstripe laminae can be observed indicative of grainflow at the toe of slope of dune sets by lee-side eddies. Foresets resting on strongly erosional bases cutting into underlying deposits.

Well Norg-5 (NOR-05)

Figure B4j:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed high-angle cross stratification. Planar stratification dominates, with top sets truncated by overlying beds. They range from slightly friable to consolidated with rare carbonate cement particularly at bed boundaries. These lithofacies were deposited as migrating aeolian dunes. Associated laminated and low-angle cross-bedded sandstones are attributed to deposition as dune bottomset or dry interdune sandsheet sediments.

Well Sauwerd-01 (SAU-01)

Figure B4j:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed high-angle cross stratification. Planar stratification dominates, with top sets truncated by overlying beds. They range from slightly friable to consolidated with rare carbonate cement particularly at bed boundaries. These lithofacies were deposited as migrating aeolian dunes. Associated laminated and low-angle cross-bedded sandstones are attributed to deposition as dune bottomset or dry interdune sandsheet sediments.

Well Sauwerd-01 (SAU-01)

Figure B4k:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed low-angle cross-stratification with increasing dip towards the top. Presence of erosional base of overlying horizontally laminated sandstone interpreted to represent bounding surface. These lithofacies were deposited as dune bottom sets or dry interdune sandsheet sediments.

Well Grijpskerk-01A (GRK-01A)

Figure B4k:

Bimodally sorted series of fine- to coarse-grained sandstones with predominantly well-developed low-angle cross-stratification with increasing dip towards the top. Presence of erosional base of overlying horizontally laminated sandstone interpreted to represent bounding surface. These lithofacies were deposited as dune bottom sets or dry interdune sandsheet sediments.

Well Grijpskerk-01A (GRK-01A)

Figure B4l:

Alternation of high-angle cross-bedded sandstones with intervals of horizontally laminated medium-grained sandstones. Boundaries of intervals representing bounding surfaces between lithofacies representing deposition in migrating dune bottomsets.

Well Grijpskerk-01A (GRK-01A)

Figure B4l:

Alternation of high-angle cross-bedded sandstones with intervals of horizontally laminated medium-grained sandstones. Boundaries of intervals representing bounding surfaces between lithofacies representing deposition in migrating dune bottomsets.

Well Grijpskerk-01A (GRK-01A)

Figure B4m:

Series of deposits characterised by presence of cross-laminated and ripple cross-laminated medium-coarse-grained sandstones. Pebble-size intraclasts present in the base of the bed at 3066.40 m are indicative for water-laid deposition under higher-energy fluvial conditions.

Well Norg-5 (NOR-05)

Figure B4m:

Series of deposits characterised by presence of cross-laminated and ripple cross-laminated medium-coarse-grained sandstones. Pebble-size intraclasts present in the base of the bed at 3066.40 m are indicative for water-laid deposition under higher-energy fluvial conditions.

Well Norg-5 (NOR-05)

Figure B4n:

Interval with horizontally to faintly wavy-laminated fine to medium-grained sandstones with layer composed of muddy rip-up clasts indicative of deposition in fluvial conditions. Upward gradual transition into yellowish massive unstructured fine to medium-grained sandstones interpreted to represent fluidised aeolian (dune?) lithofacies.

Well K17-07A

Figure B4n:

Interval with horizontally to faintly wavy-laminated fine to medium-grained sandstones with layer composed of muddy rip-up clasts indicative of deposition in fluvial conditions. Upward gradual transition into yellowish massive unstructured fine to medium-grained sandstones interpreted to represent fluidised aeolian (dune?) lithofacies.

Well K17-07A

Figure B4o:

Dry aeolian sandflat (interdune) to toeset of an aeolian dune: Horizontally laminated very fine to medium sand overlain by low-angle cross-stratified sand. Note the rapid changes in grain size from lamina to lamina, light-coloured very thin fine sand laminae from grain-fall cover thicker, darker, and coarser sand laminae (pinstripe lamination). Base of photo O shows underlying damp aeolian sandflat. The core interval indicates an intercalation of damp (Psah) and dry (Psay) aeolian sandflat deposits with only minor preservation of thin aeolian dune (Ad) beds in the Slochteren Formation.

Well Grijpskerk-01A (GRK-01A)

Figure B4o:

Dry aeolian sandflat (interdune) to toeset of an aeolian dune: Horizontally laminated very fine to medium sand overlain by low-angle cross-stratified sand. Note the rapid changes in grain size from lamina to lamina, light-coloured very thin fine sand laminae from grain-fall cover thicker, darker, and coarser sand laminae (pinstripe lamination). Base of photo O shows underlying damp aeolian sandflat. The core interval indicates an intercalation of damp (Psah) and dry (Psay) aeolian sandflat deposits with only minor preservation of thin aeolian dune (Ad) beds in the Slochteren Formation.

Well Grijpskerk-01A (GRK-01A)

Figure B4p:

Dry aeolian sandflat (Psay) with horizontally laminated fine to medium sand (photo P1). In photo P2 the horizontal lamination is interrupted by thin layers of contorted (cloudy) sand with whitish anhydrite or carbonate cementation, which formed from thin evaporitic crusts close to the sediment surface in a damp to wet sandflat environment. Dark colors of coarser-grained laminae are accentuated by black bitumen staining. The top of the core section shows the transition to an aeolian mudflat.

Well Kollumerpomp-01 (KMP-01)

Figure B4p:

Dry aeolian sandflat (Psay) with horizontally laminated fine to medium sand (photo P1). In photo P2 the horizontal lamination is interrupted by thin layers of contorted (cloudy) sand with whitish anhydrite or carbonate cementation, which formed from thin evaporitic crusts close to the sediment surface in a damp to wet sandflat environment. Dark colors of coarser-grained laminae are accentuated by black bitumen staining. The top of the core section shows the transition to an aeolian mudflat.

Well Kollumerpomp-01 (KMP-01)

Figure B4q:

Core section with top of a wettening-upward cycle in the Upper Slochteren Member. Sand, silt and clay in a patchy fabric (lower part of photo Q) formed by aeolian clastic transport in a damp sandflat with transient salt efflorescences. Evaporite minerals dissolved during subsequent flushing with undersaturated waters, leaving contorted clusters of different grain sizes in close vicinity. Note the large scatter of grain sizes in lower part of photo Q, and the upward increase of fine clastic material, eventually passing into an aeolian mudflat (Pma) at the top of photo Q. Within the mudflat fine clastics, clouds of sand are visible, indicating contortion and disruption of desiccating clay, with introduction of wind-blown sand.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B4q:

Core section with top of a wettening-upward cycle in the Upper Slochteren Member. Sand, silt and clay in a patchy fabric (lower part of photo Q) formed by aeolian clastic transport in a damp sandflat with transient salt efflorescences. Evaporite minerals dissolved during subsequent flushing with undersaturated waters, leaving contorted clusters of different grain sizes in close vicinity. Note the large scatter of grain sizes in lower part of photo Q, and the upward increase of fine clastic material, eventually passing into an aeolian mudflat (Pma) at the top of photo Q. Within the mudflat fine clastics, clouds of sand are visible, indicating contortion and disruption of desiccating clay, with introduction of wind-blown sand.

Well Blija Ferwerderadeel-101 (BLF-101)

Figure B4r:

"Wavy bedding" in fine- to medium grained sands in a damp (Psah) to wet aeolian sand-flat. Primary deposition occurred from catchment of aeolian sand on top of salt efflorescenses, which only partly dissolved later. The pale-coloured stripes and patches are remnants of formerly more complete evaporitic cementation (anhydrite, calcite), tracing irregularities of depositional surfaces (abrupt changes in grain size). White speckles indicate anhydritic (concretionary) cementation. Some laminae resemble adhesion-ripple layers. This kind of depositional facies and diagenetic overprint generally results in small disconnected patchy clusters of good porosity but overall poor reservoir quality.

Well Grijpskerk-01A (GRK-01A)

Figure B4r:

"Wavy bedding" in fine- to medium grained sands in a damp (Psah) to wet aeolian sand-flat. Primary deposition occurred from catchment of aeolian sand on top of salt efflorescenses, which only partly dissolved later. The pale-coloured stripes and patches are remnants of formerly more complete evaporitic cementation (anhydrite, calcite), tracing irregularities of depositional surfaces (abrupt changes in grain size). White speckles indicate anhydritic (concretionary) cementation. Some laminae resemble adhesion-ripple layers. This kind of depositional facies and diagenetic overprint generally results in small disconnected patchy clusters of good porosity but overall poor reservoir quality.

Well Grijpskerk-01A (GRK-01A)

Figure B4s:

Transition from a sheetflood sandstone (Fh) into suspension deposits of a pond (Bp), which was possibly formed by the same flood event (photo S). A desiccation crack filled with pale-coloured sand cuts down through both mud and sand. The crack-filling sand later carried formation waters that bleached the adjacent red mud interval. The core interval displays a relatively wet intercalation in a dominantly dry aeolian setting.

Well Grijpskerk-01A (GRK-01A)

Figure B4s:

Transition from a sheetflood sandstone (Fh) into suspension deposits of a pond (Bp), which was possibly formed by the same flood event (photo S). A desiccation crack filled with pale-coloured sand cuts down through both mud and sand. The crack-filling sand later carried formation waters that bleached the adjacent red mud interval. The core interval displays a relatively wet intercalation in a dominantly dry aeolian setting.

Well Grijpskerk-01A (GRK-01A)

Figure B4t:

Core interval presents a damp hydrological environment during Slochteren deposition with damp to wet aeolian sandflat (Psah, Psaw), sheetflood (Fh), and preserved pond (Bp) deposits. The lower 10 cm of photo T shows ripple laminated argillaceous sandstone forming the upper part of this sheetflod deposit, which is overlain by 15 cm deposits of a damp to wet evaporitic sandflat with grey (bleached) sandstones with white spots and patches of concretionary anhydrite or calcite cementation. Haloturbation has extensively modified primary depositional structures. The more muddy sediment towards the top of photo T has also been haloturbated and was less affected by bleaching.

Well Grijpskerk-01A (GRK-01A)

Figure B4t:

Core interval presents a damp hydrological environment during Slochteren deposition with damp to wet aeolian sandflat (Psah, Psaw), sheetflood (Fh), and preserved pond (Bp) deposits. The lower 10 cm of photo T shows ripple laminated argillaceous sandstone forming the upper part of this sheetflod deposit, which is overlain by 15 cm deposits of a damp to wet evaporitic sandflat with grey (bleached) sandstones with white spots and patches of concretionary anhydrite or calcite cementation. Haloturbation has extensively modified primary depositional structures. The more muddy sediment towards the top of photo T has also been haloturbated and was less affected by bleaching.

Well Grijpskerk-01A (GRK-01A)

Figure B4u:

The Slochteren sandstones in the Ameland area are located in a relatively distal position in the playa-margin area, which is the sandy coastal belt of the playa lake. The core section depicts a typical succession of facies from damp to wet aeolian sandflat (Psah, Psaw) to mudflat deposition (Pma). Haloturbation has obliterated most of the primary sedimentary structures in damp aeolian sandflat facies (photo U), but only minor amounts of evaporite cements (white speckles) have been preserved. The formerly red sand layers were bleached to gray colours during early hydrocarbon migration.

Well Ameland Oost-106 (AME-106)

Figure B4u:

The Slochteren sandstones in the Ameland area are located in a relatively distal position in the playa-margin area, which is the sandy coastal belt of the playa lake. The core section depicts a typical succession of facies from damp to wet aeolian sandflat (Psah, Psaw) to mudflat deposition (Pma). Haloturbation has obliterated most of the primary sedimentary structures in damp aeolian sandflat facies (photo U), but only minor amounts of evaporite cements (white speckles) have been preserved. The formerly red sand layers were bleached to gray colours during early hydrocarbon migration.

Well Ameland Oost-106 (AME-106)

Figure B4v:

The Annerveen field is located in a relatively proximal position south of the Groningen field. The core section shows a typical stacking of sandy to conglomeratic fluvial facies (Cfb), sheetflood (Fh), and ephemeral-pond deposits (Bp). Photo V illustrates lithotypes on top of a fining- upward interval with basal laminated clay and siltstone, deposited from flood events in ephemeral ponds, which desiccated and were subsequently covered by sheetflood (or wind-blown?) sand. The contortion of the thin sand layers was due to haloturbation (evaporation of saline groundwaters, expansive growth of evaporite minerals); a desiccation crack in a thin sand layer close to the top of photo V indicates less presence of salt water during cracking (early evaporite cementation would prevent shrinkage). The complex mixing of clay chips and pellets of different grain size is evidence that parts of the mudstones were redeposited by wind or water action.

Well Annerveen-01 (ANN-01)

Figure B4v:

The Annerveen field is located in a relatively proximal position south of the Groningen field. The core section shows a typical stacking of sandy to conglomeratic fluvial facies (Cfb), sheetflood (Fh), and ephemeral-pond deposits (Bp). Photo V illustrates lithotypes on top of a fining- upward interval with basal laminated clay and siltstone, deposited from flood events in ephemeral ponds, which desiccated and were subsequently covered by sheetflood (or wind-blown?) sand. The contortion of the thin sand layers was due to haloturbation (evaporation of saline groundwaters, expansive growth of evaporite minerals); a desiccation crack in a thin sand layer close to the top of photo V indicates less presence of salt water during cracking (early evaporite cementation would prevent shrinkage). The complex mixing of clay chips and pellets of different grain size is evidence that parts of the mudstones were redeposited by wind or water action.

Well Annerveen-01 (ANN-01)

Figure B4w:

Gamma-ray profile of Lower Slochteren Member (ROSLL) in offshore well K06-06, with core position close to the base of Rotliegend, above the Carboniferous Hospital Ground Formation (DCDG) (see Figure B1h, page 291). Distal reaches of fluvial sand, supplied by ephemeral flooding events, characterise the Rotliegend succession. Fine clastics from suspension were deposited on top of the bed-load sands in ephemeral ponds. Desiccation of these ponds is evidenced by cracks. Sand was transported from the south by ephemeral fluvial systems with source areas at the London Brabant Massif and adjacent Variscan highs. Close to the base of core photo W2 and near the top of photo W3, a patchy fabric of the sand indicates minor wind reworking and redeposition in thin damp-aeolian-sandflat intervals.

Well K06-06

Figure B4w:

Gamma-ray profile of Lower Slochteren Member (ROSLL) in offshore well K06-06, with core position close to the base of Rotliegend, above the Carboniferous Hospital Ground Formation (DCDG) (see Figure B1h, page 291). Distal reaches of fluvial sand, supplied by ephemeral flooding events, characterise the Rotliegend succession. Fine clastics from suspension were deposited on top of the bed-load sands in ephemeral ponds. Desiccation of these ponds is evidenced by cracks. Sand was transported from the south by ephemeral fluvial systems with source areas at the London Brabant Massif and adjacent Variscan highs. Close to the base of core photo W2 and near the top of photo W3, a patchy fabric of the sand indicates minor wind reworking and redeposition in thin damp-aeolian-sandflat intervals.

Well K06-06

Figure B4x:

Fluvial channel deposits (Cf) in the mudstone-dominated Ten Boer Member (Silverpit Formation). In photo X, mud-dominated playa deposits (Pmk), typical of the Ten Boer Member, display rippled aquatic sand transport (current or wave-ripple formation, M.S,x and S1l,x) with the mudstones either structureless, homogenized, or indistinctly laminated. The basal part of photo X shows a mudstone with disrupted fabric possibly due to aquatic reworking, including sandy matrix.

Well Norg-5 (NOR-05)

Figure B4x:

Fluvial channel deposits (Cf) in the mudstone-dominated Ten Boer Member (Silverpit Formation). In photo X, mud-dominated playa deposits (Pmk), typical of the Ten Boer Member, display rippled aquatic sand transport (current or wave-ripple formation, M.S,x and S1l,x) with the mudstones either structureless, homogenized, or indistinctly laminated. The basal part of photo X shows a mudstone with disrupted fabric possibly due to aquatic reworking, including sandy matrix.

Well Norg-5 (NOR-05)

Figure B4y:

Core section from well Grijpskerk-01A (GRK-01A), Grijpskerk UGS west of Groningen field. The core section demonstrates typical distal intercalation of sheetflood sand deposition (Fh) in a setting dominated by mudflat and lacustrine deposition (ponds Bp, wet aeolian sandflats Psaw, playa wet and evaporitic mudflats). Sheetflood suspension became ponded and deposited fines above the sand layers, depicted in photo Y. Sedimentary structures in the sand were overprinted by diagenetic processes including evaporite cementation, bleaching, and bitumen impregnation.

Well Grijpskerk-01A (GRK-01A)

Figure B4y:

Core section from well Grijpskerk-01A (GRK-01A), Grijpskerk UGS west of Groningen field. The core section demonstrates typical distal intercalation of sheetflood sand deposition (Fh) in a setting dominated by mudflat and lacustrine deposition (ponds Bp, wet aeolian sandflats Psaw, playa wet and evaporitic mudflats). Sheetflood suspension became ponded and deposited fines above the sand layers, depicted in photo Y. Sedimentary structures in the sand were overprinted by diagenetic processes including evaporite cementation, bleaching, and bitumen impregnation.

Well Grijpskerk-01A (GRK-01A)

Figure B4z:

Continuation of Figure B4y with distal sheetfloods in a mudflat setting. Photo Z shows mud-clast reworking during sand transport in sheetflood events. Only thin sand layers were accreted; slight contortion of both thin sand and mud layers can have formed from desiccation. Bleaching in sandstone layers and adjacent red clays and muds and bitumen impregnation indicate that interconnectedness of these thin sands, interrupted by clay partings, has been sufficient to allow hydrocarbon migration.

Well Grijpskerk-01A (GRK-01A)

Figure B4z:

Continuation of Figure B4y with distal sheetfloods in a mudflat setting. Photo Z shows mud-clast reworking during sand transport in sheetflood events. Only thin sand layers were accreted; slight contortion of both thin sand and mud layers can have formed from desiccation. Bleaching in sandstone layers and adjacent red clays and muds and bitumen impregnation indicate that interconnectedness of these thin sands, interrupted by clay partings, has been sufficient to allow hydrocarbon migration.

Well Grijpskerk-01A (GRK-01A)

Figure B4aa:

Wet aeolian sandflat deposits (Psaw) with siltstones and very fine-grained to fine-grained sandstones. Patchy sand fabric is typical in these facies with discontinuous irregular domains of silt and sand, sometimes with clusters of small clay flakes or pellets. Good to very good sorting of individual sand clusters is evidence for aeolian transport; deposition possibly occurred by adhesion on wet sticky surfaces or in the wind shadow of salt efflorescences. It is interpreted that disruption and contortion of the aeolian patches are caused by the dissolution of halitic efflorescences. Small nodules of white anhydrite are preserved in fine-grained intervals of photo AA1.

Well Ameland Oost-106 (AME-106)

Figure B4aa:

Wet aeolian sandflat deposits (Psaw) with siltstones and very fine-grained to fine-grained sandstones. Patchy sand fabric is typical in these facies with discontinuous irregular domains of silt and sand, sometimes with clusters of small clay flakes or pellets. Good to very good sorting of individual sand clusters is evidence for aeolian transport; deposition possibly occurred by adhesion on wet sticky surfaces or in the wind shadow of salt efflorescences. It is interpreted that disruption and contortion of the aeolian patches are caused by the dissolution of halitic efflorescences. Small nodules of white anhydrite are preserved in fine-grained intervals of photo AA1.

Well Ameland Oost-106 (AME-106)

Figure B4ab:

Transition of sandy mudstone from a wet sandflat (Psaw) into mudstone facies of a muddy playa to lacustrine system (Bb). The playa mudstones are macroscopically structureless, but can show microscopic mud-pellet texture. Wind-blown sand-sized clay particles accumulated as aeolian dunes (clay lunettes). An alternative mechanism forming the structureless appearance is multiple wetting and desiccation cycles of playa mud deposits. Small white anhydrite nodules are present in the lower, sandy part of the photo.

Well Bierum-13B (BIR-13B)

Figure B4ab:

Transition of sandy mudstone from a wet sandflat (Psaw) into mudstone facies of a muddy playa to lacustrine system (Bb). The playa mudstones are macroscopically structureless, but can show microscopic mud-pellet texture. Wind-blown sand-sized clay particles accumulated as aeolian dunes (clay lunettes). An alternative mechanism forming the structureless appearance is multiple wetting and desiccation cycles of playa mud deposits. Small white anhydrite nodules are present in the lower, sandy part of the photo.

Well Bierum-13B (BIR-13B)

Figure B4ac:

Example of a succession of aeolian mudflat deposits (Pma) with intercalations of lacustrine intervals (Bb, desert lake) and distal sheetflood sandstones (Fh). Patchy irregular fabric is dominant in aeolian muddy deposits with rapid changes in fine grain sizes from clay to coarse silt. On top of sheetflood sands the dark red claystones deposited from a shallow standing water body still show indistinct lamination which becomes contorted upward by desiccation and crack fills. Sandstones have horizontal lamination, sometimes with rippled tops.

Well K02-02

Figure B4ac:

Example of a succession of aeolian mudflat deposits (Pma) with intercalations of lacustrine intervals (Bb, desert lake) and distal sheetflood sandstones (Fh). Patchy irregular fabric is dominant in aeolian muddy deposits with rapid changes in fine grain sizes from clay to coarse silt. On top of sheetflood sands the dark red claystones deposited from a shallow standing water body still show indistinct lamination which becomes contorted upward by desiccation and crack fills. Sandstones have horizontal lamination, sometimes with rippled tops.

Well K02-02

Figure B4ad:

Mud-dominated halitic playa deposit (Pmk) above salt layer. The transition from discontinuous, more or less pure halite layers to mud can be gradual. Multiple phases of intrastratal halite dissolution and reprecipitation can lead to distinct boundaries between clays and muds and halite, giving it a brecciated appearance. Macroscopically no laminated clay is preserved from periods of aqueous clay deposition.

Well E09-01

Figure B4ad:

Mud-dominated halitic playa deposit (Pmk) above salt layer. The transition from discontinuous, more or less pure halite layers to mud can be gradual. Multiple phases of intrastratal halite dissolution and reprecipitation can lead to distinct boundaries between clays and muds and halite, giving it a brecciated appearance. Macroscopically no laminated clay is preserved from periods of aqueous clay deposition.

Well E09-01

Figure B5a:

Partially bleached sandstone, Well Oosterwolde-01 (OWD-01). Thin section photo A: completely bleached white sandstone interval with high intergranular porosity; Thin section photo B: porous red sandstone interval with hematite coating on grain surfaces, ba = barite cement. Grey colours in the upper part of the core indicate bitumen impregnation after bleaching. Porosity in blue.

Well Oosterwolde-01 (OWD-01)

Figure B5a:

Partially bleached sandstone, Well Oosterwolde-01 (OWD-01). Thin section photo A: completely bleached white sandstone interval with high intergranular porosity; Thin section photo B: porous red sandstone interval with hematite coating on grain surfaces, ba = barite cement. Grey colours in the upper part of the core indicate bitumen impregnation after bleaching. Porosity in blue.

Well Oosterwolde-01 (OWD-01)

Figure B5b:

Wavy irregularly laminated sandstone of damp-aeolian-sand-flat facies (Psah). The sandstone is partially cemented with dolomite (whitel patches or laminae-like features), preserved as corroded rhombs (as in B1: dol) or blocky pore fills. After the grain-size (-layer) -selective dissolution of dolomite and precipitation of kaolinite booklets (k), bitumen impregnation resulted in the grey to dark grey color of the formerly red sandstone. Porosity in blue.

Well Grijpskerk-01A (GRK-01A)

Figure B5b:

Wavy irregularly laminated sandstone of damp-aeolian-sand-flat facies (Psah). The sandstone is partially cemented with dolomite (whitel patches or laminae-like features), preserved as corroded rhombs (as in B1: dol) or blocky pore fills. After the grain-size (-layer) -selective dissolution of dolomite and precipitation of kaolinite booklets (k), bitumen impregnation resulted in the grey to dark grey color of the formerly red sandstone. Porosity in blue.

Well Grijpskerk-01A (GRK-01A)

Figure B5c:

An example of partly homogenised and bleached aeolian sandstone (Weissliegend) below the black bituminous shales of the Coppershale Member (subenvironment Ba) in Well K15-15A. Thin section A1 with intergranular kaolinite (k) and siderite (s), A2 floating grains and domains of different intergranular volume, A3 leached anhydrite (an). Porosity in blue.

Well K15-15A

Figure B5c:

An example of partly homogenised and bleached aeolian sandstone (Weissliegend) below the black bituminous shales of the Coppershale Member (subenvironment Ba) in Well K15-15A. Thin section A1 with intergranular kaolinite (k) and siderite (s), A2 floating grains and domains of different intergranular volume, A3 leached anhydrite (an). Porosity in blue.

Well K15-15A

Figure B5d:

Whitish dolomite speckles in aeolian sandstone of Well Westbeemster-01 (WBMS-01). The pore space within the whitish speckles is completely occluded by (early) dolomite (thin section photomicrographs A1 and A2, cross-polarised light). The darker parts of the core show porosity created by the partial dissolution of dolomite.

Well Westbeemster-01 (WBMS-01)

Figure B5d:

Whitish dolomite speckles in aeolian sandstone of Well Westbeemster-01 (WBMS-01). The pore space within the whitish speckles is completely occluded by (early) dolomite (thin section photomicrographs A1 and A2, cross-polarised light). The darker parts of the core show porosity created by the partial dissolution of dolomite.

Well Westbeemster-01 (WBMS-01)

Figure B5e:

Bleached sandstone with dark streaks and patches due to the presence of bitumen, which appears as black pore-lining coats in thin-section photomicrographs A1, A2, and A3. Porosity in blue.

Well K15-09

Figure B5e:

Bleached sandstone with dark streaks and patches due to the presence of bitumen, which appears as black pore-lining coats in thin-section photomicrographs A1, A2, and A3. Porosity in blue.

Well K15-09

Figure B5f:

Extensive illite growth has reduced the reservoir quality (Phi = 15.1 %, Kh = 0.28 mD) of this bleached sandstone (photos A1 and A2, greenish-appearing meshwork illites on grain surfaces). The pore connectivity is severely reduced by delicate illite plates or fibers which span across pore throats (photo A2, arrows). Photo A3 shows the typical birefingence colour of illite cutans or coatings tangentially to grain surfaces under cross-polarised light. The minute and very thin illite plates in the meshworks are just visible under cross-polarised light here.

Well P02-09

Figure B5f:

Extensive illite growth has reduced the reservoir quality (Phi = 15.1 %, Kh = 0.28 mD) of this bleached sandstone (photos A1 and A2, greenish-appearing meshwork illites on grain surfaces). The pore connectivity is severely reduced by delicate illite plates or fibers which span across pore throats (photo A2, arrows). Photo A3 shows the typical birefingence colour of illite cutans or coatings tangentially to grain surfaces under cross-polarised light. The minute and very thin illite plates in the meshworks are just visible under cross-polarised light here.

Well P02-09

Figure B5g:

Partial bleaching of red reservoir sandstone along fracture in Well Hantum-01 (HTM-01). In photos A1 and A2 the relatively thick illite plates on grain surfaces show typical birefringence (arrows). In A2 kaolinite (k) (dickite?) booklets fill a pore after feldspar dissolution; kaolinite in adjacent pores is partly illitised. This extensive illitisation is typical of reservoirs close to major faults, here the Hantum fault, but also reservoirs adjacent to minor faults which are hydraulically linked to more prominent major faults can show intensive illitisation after dickite formation.

Well Hantum-01 (HTM-01)

Figure B5g:

Partial bleaching of red reservoir sandstone along fracture in Well Hantum-01 (HTM-01). In photos A1 and A2 the relatively thick illite plates on grain surfaces show typical birefringence (arrows). In A2 kaolinite (k) (dickite?) booklets fill a pore after feldspar dissolution; kaolinite in adjacent pores is partly illitised. This extensive illitisation is typical of reservoirs close to major faults, here the Hantum fault, but also reservoirs adjacent to minor faults which are hydraulically linked to more prominent major faults can show intensive illitisation after dickite formation.

Well Hantum-01 (HTM-01)

Figure B5h:

Red reservoir sandstone with hematite staining on grain surfaces. In photo A1 a large part of the intergranular volume is occupied by siderite (s) and kaolinite (k). The siderite is interpreted as a late diagenetic product that replaced earlier blocky cements (?dolomite) and detrital grains. Photo A2, which is a close-up of A1, shows kaolinite which probably replaced a grain or cement patch and which predates barite (ba). Photo A3 shows the same area as photo A1 under cross-polarised light. An orange tan on the core surface is the result of oxidation of abundant siderite (see base of core photo). Well K15-09, pores are blue in Photo A1 and A2.

Well K15-09

Figure B5h:

Red reservoir sandstone with hematite staining on grain surfaces. In photo A1 a large part of the intergranular volume is occupied by siderite (s) and kaolinite (k). The siderite is interpreted as a late diagenetic product that replaced earlier blocky cements (?dolomite) and detrital grains. Photo A2, which is a close-up of A1, shows kaolinite which probably replaced a grain or cement patch and which predates barite (ba). Photo A3 shows the same area as photo A1 under cross-polarised light. An orange tan on the core surface is the result of oxidation of abundant siderite (see base of core photo). Well K15-09, pores are blue in Photo A1 and A2.

Well K15-09

Figure B6a:

Bleaching halo (arrows) around reactivated fracture. Dominant fracture fill is quartz, followed by clay forming dilational shears. Abundant clay content in the wallrock. Fractures are clustered and show both normal and reverse offsets (mm scale). Fractures are oblique and perpendicular to bedding.

Well K07-01

Figure B6a:

Bleaching halo (arrows) around reactivated fracture. Dominant fracture fill is quartz, followed by clay forming dilational shears. Abundant clay content in the wallrock. Fractures are clustered and show both normal and reverse offsets (mm scale). Fractures are oblique and perpendicular to bedding.

Well K07-01

Figure B6b:

Barite-cemented fracture (arrow). Extensive mineral growth occurred within and around the fracture.

Well K11-01

Figure B6b:

Barite-cemented fracture (arrow). Extensive mineral growth occurred within and around the fracture.

Well K11-01

Figure B6c:

Dilational shear fracture (cemented or partly cemented fracture with sliding and rolling of intact grains past each other by fracture dilation). A diagenetic halo is present resulting from hydrocarbon movement along the fracture. Microfaults with dominant reverse offsets (mm scale) are present. Bedding drag is visible below the plug position (arrow).

Well K11-01

Figure B6c:

Dilational shear fracture (cemented or partly cemented fracture with sliding and rolling of intact grains past each other by fracture dilation). A diagenetic halo is present resulting from hydrocarbon movement along the fracture. Microfaults with dominant reverse offsets (mm scale) are present. Bedding drag is visible below the plug position (arrow).

Well K11-01

Figure B6d:

An example of a complex fracture array (possibly cataclastic) with no visible offset. Fluid circulation (hydrocarbons?) caused a diagenetic (cement) halo around the fracture (arrow). Cataclastic processes and extensive mineral growth took place within and adjacent to the fracture during and soon after deformation.

Well K11-01

Figure B6d:

An example of a complex fracture array (possibly cataclastic) with no visible offset. Fluid circulation (hydrocarbons?) caused a diagenetic (cement) halo around the fracture (arrow). Cataclastic processes and extensive mineral growth took place within and adjacent to the fracture during and soon after deformation.

Well K11-01

Figure B6e:

Quartz-cemented fracture that terminates against thin shale streak (black arrow) and splays against harder cemented layer (blue arrow) at 3960.67 m.

Well K15-12

Figure B6e:

Quartz-cemented fracture that terminates against thin shale streak (black arrow) and splays against harder cemented layer (blue arrow) at 3960.67 m.

Well K15-12

Figure B6f:

Cataclastic fracture with some small offset visible (arrow).

Well K17-01

Figure B6f:

Cataclastic fracture with some small offset visible (arrow).

Well K17-01

Figure B6g:

Two phases of fractures. The first fracture phase is cataclastic (black arrow). The second phase of fracturing intersects the first cataclastic fractures and has resulted in partly open, partly cemented fractures. Iron staining is present near the intersection point (blue arrow). Clearly an example of differential cementation.

Well K17-01

Figure B6g:

Two phases of fractures. The first fracture phase is cataclastic (black arrow). The second phase of fracturing intersects the first cataclastic fractures and has resulted in partly open, partly cemented fractures. Iron staining is present near the intersection point (blue arrow). Clearly an example of differential cementation.

Well K17-01

Figure B6h:

An example of fracture arrestment. The cataclastic fracture is arrested by a thin cemented layer (arrow).

Well K17-01

Figure B6h:

An example of fracture arrestment. The cataclastic fracture is arrested by a thin cemented layer (arrow).

Well K17-01

Figure B6i:

A dilational, quartz-cemented fracture (black arrow) with offset of laminae (blue arrow).

Well K17-01

Figure B6i:

A dilational, quartz-cemented fracture (black arrow) with offset of laminae (blue arrow).

Well K17-01

Figure B6j:

An example of two generations of fractures which are intersecting and show complex fracture arrays.

Well K17-01

Figure B6j:

An example of two generations of fractures which are intersecting and show complex fracture arrays.

Well K17-01

Figure B6k:

An example of open and cemented fractures through conglomerates. Note that pebbles are split by the fractures (arrows). The tensile fractures are oriented subparallel to each other in an anastomosing pattern.

Well K17-01

Figure B6k:

An example of open and cemented fractures through conglomerates. Note that pebbles are split by the fractures (arrows). The tensile fractures are oriented subparallel to each other in an anastomosing pattern.

Well K17-01

Figure B6l:

An example of a cemented fracture with diagenetic halo (arrow).

Well K17-04

Figure B6l:

An example of a cemented fracture with diagenetic halo (arrow).

Well K17-04

Figure B6m:

Examples of cataclastic fractures.

Well K17-05

Figure B6m:

Examples of cataclastic fractures.

Well K17-05