Abstract Sediment provenance studies concern the origin, composition, transportation and deposition of detritus, and are therefore an important part of understanding the links between basinal sedimentation, and hinterland tectonics and unroofing. Such studies can add value at many stages of hydrocarbon exploitation, from identifying regional-scale crustal affinities and sediment-dispersal patterns during the earliest stages of exploration to detailed correlation in producing reservoirs and understanding the impact of mineralogy on reservoir diagenesis. This Special Publication records 20 of the papers given at the conference titled ‘Sediment Provenance Studies in Hydrocarbon Exploration and Production’ organized by the Petroleum Group of the Geological Society of London, and held in London from 5 to 7 December 2011. The observations drawn in this introductory section reflect the volume editors’ experience, presentations at the conference and papers within this volume.

Abstract Three distinct analytical approaches are embraced in mineral–chemical stratigraphy: mineralogy, whole-rock geochemistry and single-grain geochemical analysis. Mineralogical studies identify and quantify the clastic components of sandstone, even though any clast category may be geochemically diverse. Whole-rock geochemical studies (sometimes referred to as chemostratigraphy), by contrast, quantify the abundance of major and trace elements in sandstone, but provide no information on the distribution and location of the elements in minerals. These approaches are linked by single-grain geochemical analysis, which enables further characterization and subdivision of individual mineralogical components, and identifies sites where specific major and trace elements reside. In this paper, we consider the relationships between minerals, mineral chemistry and whole-rock composition, before exploring the value of mineral–chemical stratigraphy for lithostratigraphic correlation and evaluation of sediment provenance, using published examples from the North Sea region, where the great majority of such studies have been undertaken. We conclude by discussing the important role that alluvial basins play in controlling mineral–chemical signatures.

Abstract Deep-water turbidite sandstone reservoirs in the Gulf of Mexico have been sourced from a variety of provenance terrains. As a result, the framework composition of each reservoir in the basin varies widely, including volcanic-rich litharenite (Oligocene Vicksburg), feldspathic-rich lithic arkose (Oligocene Frio), metamorphic-rich feldspathic litharenite (Palaeogene Wilcox), lithic-poor quartzarenite (Miocene), quartz-rich sublitharenite (Cretaceous) and quartz- and feldspar-rich subarkose (Norphlet). Provenance-driven differences in composition have a complex but critical influence on how each of these reservoirs responds to burial-induced changes in depth, fluid pressure, effective stress and temperature. A combination of Petromod® and Touchstone™ modelling programs are used in this study to simulate the influence of provenance on compaction and cementation of the main reservoir types in the Gulf of Mexico. For example, modelling results predict that at higher levels of thermal exposure, some lithic-rich sands, although more ductile and highly compacted, will experience less quartz cementation than less ductile, quartz-rich sands, thereby preserving a higher range of porosity and permeability. Furthermore, modelling results predict that temperature/effective stress/depth windows for optimal reservoir quality preservation vary widely depending on sandstone provenance.

Abstract The Miocene Diligencia Formation of southern California was deposited in an alluvial/fluvial depositional system developed within the Diligencia basin. This basin formed as an extensional half-graben during latest Oligocene–Early Miocene crustal extension. This continental half-graben was superposed on an Eocene fault-controlled submarine canyon, in which the Maniobra Formation was deposited. The arkosic composition of the sandstone framework would predict a high-quality reservoir with preserved primary porosity or at least important intergranular volume (IGV). However, inspection of sandstone samples indicates that diagenesis was intense, as several diagenetic processes drastically reduced the reservoir quality. Dominant diagenetic processes were compaction and cementation. Mechanical compaction, expressed as intense deformation of ductile grains and chemical compaction in the form of pressure solution, reduced the IGV of sandstone at the bases of the Maniobra and Diligencia formations to low levels (10–20%). In the upper parts of both units, early diagenetic cements partially inhibited compaction, maintaining IGV values close to 35%. Several mineral phases constitute cements responsible for occlusion of primary porosity. Many of these phases also replaced framework components and early cements. The more important cements are: (1) quartz and K-feldspar, which appear mainly as grain overgrowths, although quartz mosaics have been observed at the base of the Maniobra Formation; (2) carbonates, such as ankerite, dolomite and calcite in diverse textures and with significant occluding character; (3) phyllosilicates, such as kaolin, that developed mainly in Diligencia sandstone as early pore fillings, and locally as illite coats around detrital grains; and (4) other mineral phases, such as Fe-oxides and fluorite, which occur exclusively at the base of the Maniobra Formation, exhibiting aggressive textures against framework grains and older cements. The chronology of diagenetic processes includes marine early diagenesis (eodiagenesis) for Maniobra sandstone, characterized by K-feldspar, ankerite and dolomite cements. Continental early diagenesis is identified in Diligencia sandstone, manifested by the presence of smectite (replaced by illite), kaolin and Fe-oxide cements. Mesodiagenetic processes are similar in both formations. In addition, hydrothermal phases (fluorite and quartz mosaics) are identified at the base of the Maniobra Formation. Diagenetic mineral associations suggest palaeotemperatures above 130 °C. The geotectonic scenario in which diagenesis occurred explains these post-depositional processes. During latest Oligocene–Early Miocene crustal extension, the Diligencia basin developed in an area of high heat flow, as expressed in the eruption of interbedded basaltic–andesitic lavas. High heat flow favoured compaction and cementation, accelerating these diagenetic processes during a relative short time interval. Hydrothermal fluxes produced mineral phases that contributed to the destruction of a potentially good reservoir by intense diagenesis. Supplementary material: Optical analysis: point count and recalculated parameters are available at http://www.geolsoc.org.uk/SUP18650 .

Abstract The intraplate Cameros Rift Basin in northern Spain, which has sediments some 6500 m thick, developed between the Late Jurassic and Early Albian. Its facies and their distribution in the sedimentary record suggest the basin may contain hydrocarbon systems. The arenite composition of the basin reveals two main petrofacies: (1) a quartzolithic petrofacies, the provenance of which is related to recycling processes that took place in the pre-rift sedimentary cover; and (2) a quartzofeldspathic petrofacies mainly related to the erosion of a plutonic and metamorphic source of arenite. The succession of these petrofacies reflects two main cycles representing the progressive erosion of their sources, one of 10 Ma, the other of 30 Ma. Such succession is typical of a non-volcanic rift basin. The quartzolithic petrofacies shows early carbonate cements that inhibited compaction and later quartz, feldspar and clay mineral diagenetic phases. The quartzofeldspathic petrofacies has a rigid framework that maintained the original pores of the arenite during burial diagenesis. Quartz and K-feldspar overgrowths are common, with secondary porosity occurring as a product of feldspar dissolution. The quartzofeldspathic petrofacies has a greater potential to act as a hydrocarbon reservoir. This study corroborates the close relationship between the provenance of arenite and its reservoir potential in continental rift basins.

Abstract The reservoir characterization and provenance of the Wolfville Formation were investigated using petrography, heavy minerals and microprobe analysis of tourmaline and garnet. Sandstone samples were taken from exposures at Rainy Cove and Cambridge Cove, and from the subsurface at Chinampas N-37 well beneath the Bay of Fundy. The surface and subsurface rocks have differences in their relative content and/or type of detritus, cement and heavy minerals (opaques, garnet, scheelite, tourmaline, rutile, apatite and others). These sandstones have continental block provenance in the subsurface rocks and recycled orogen provenance in the exposures. The main sources of the exposed Wolfville Formation sediments were the Palaeozoic rocks of the Meguma Supergroup, South Mountain Batholith, Horton and Windsor groups; meanwhile the subsurface sandstones might have been derived from the same sources or the Avalon Terrane and/or Gondwana. The sandstones were deposited during early stages of rifting post-dating earlier Palaeozoic collision orogenies that culminated with the Appalachian orogeny. The exposures of Wolfville Formation have low porosity ( c. 6%) that diminishes to negligible in the subsurface. The Wolfville Formation has a considerable thickness beneath the Bay of Fundy where it overlies the Horton Bluff Formation, Meguma and/or Avalon terranes. However, its reservoir potential is not encouraging.

Abstract Oligo-Miocene outcrops along the southern margin of the western Greater Caucasus preserve a record of sediments shed from the range into the northern and central parts of the Eastern Black Sea. Sandstones in the Russian western Caucasus are significantly more quartz-rich than those located farther SE in western Georgia. The latter contain appreciably more mudstone and volcanic rock fragments. Oligo-Miocene turbidite systems derived from the Russian western Caucasus in the Tuapse Trough and central Eastern Black Sea may therefore form better-quality reservoirs at shallow to moderate depths than sediments derived from west Georgian volcaniclastic sources in the easternmost part of the basin. Palynomorph analysis indicates sediment derivation predominantly from Jurassic and Cretaceous strata in the Russian western Caucasus and from Eocene strata, and an increasing proportion of Cretaceous strata upsection, in western Georgia. An Eocene volcaniclastic source is proposed for the increased rock fragment component in west Georgian sandstones. Eocene volcaniclastic rocks are no longer exposed in the Greater Caucasus, but similar rocks form the inverted fill of the Adjara–Trialet Basin farther south in the Lesser Caucasus. The former presence of a northern strand of this basin in the west Georgian Caucasus is supported by earlier thermochronological work. Supplementary material: A sample data table, petrographic data table, petrographic key, QFL sandstone compositional plot and palynomorph reworking Stratabugs™ charts are available at www.geolsoc.org.uk/SUP18662 .

Abstract Detrital garnet suites have been demonstrated to be reliable indicators of the mineralogical and lithological characteristics of sediment source areas. This study applies garnet analysis to the Paleocene to Eocene Sele Formation deep-water sandstone units of the central North Sea. These stratigraphic units are economically important as they represent one of the main hydrocarbon reservoir intervals in this mature basin. The routing of turbidity currents into the Central Graben has been demonstrated to be related to axial fans (ultimately sourced from Lewisian and Moine basement rocks and Triassic sandstones to the NW) and lateral fans (ultimately sourced from the Dalradian basement rocks to the west). Garnet analysis suggests the majority of samples can be attributed to the axial fan system and that the lateral system contributed little to sandstone deposition east of the Gannet Fields. This contradicts previous seismic mapping work, which suggested that the lateral fan system dominated sedimentation as far east as the Merganser Field. This reinterpretation is potentially important for our understanding of sediment routing and its impact on the distribution of reservoir quality, particularly as this is believed to relate directly to proximity to the shelf.

Abstract A heavy mineral, mineral chemical and detrital zircon study of Jurassic–Cretaceous (Bathonian–Valanginian) sandstones of the Andøya B borehole, Lofoten–Vesterålen, northern Norway, has revealed the existence of significant differences within the succession. These are related partly to changes in source and partly to variations in the extent of weathering during alluvial storage. Three mineralogical units have been identified. The main change takes place within the Bathonian, and is interpreted as marking a switch from eastern (West Troms) to western (Andøya–Lofoten High) sourcing, consistent with previously published sedimentological models. U–Pb age data indicate that most of the zircons were derived from Palaeoproterozoic rocks ( c. 1750–1860 Ma), with a subordinate Archaean group ( c. 2600–2800 Ma) and a small early Palaeozoic group (mostly in the 435–446 Ma range). These groups can all be tied back to lithological components of the Lofoten–Vesterålen and West Troms regions, including Palaeozoic rocks hosted in Caledonian allochthons. The provenance characteristics of the Andøya succession have no counterpart in Cretaceous and Paleocene sandstones of the Vøring Basin. This suggests that sediment fed into the basin from Lofoten–Vesterålen was of minor importance, and that prospective Cretaceous–Paleocene hydrocarbon reservoir sandstones in the Vøring Basin were mainly derived from either northern Nordland or northern East Greenland. Supplementary material: Zircon isotopic compositions and ages are available at http://www.geolsoc.org.uk/SUP18616 .

Abstract This paper uses an extensive dataset from more than 200 samples to provide a comprehensive source-to-sink analysis of the Amur River and its delta in the Russian Far East. The majority of sand-sized sediment in the Amur River and its former delta comes from upstream of the Lesser Khingan Ridge, shown by uniformity of sediment composition in the lower 1700 km of the river. Stable mineral ratios, U–Pb age spectra and garnet geochemistry show little stratigraphic provenance-specific variation in the Neogene delta. This renders Miocene–Pliocene drainage capture models unlikely. The onset of uplift in the delta is marked by a decrease in the apatite–tourmaline index (ATi) in Upper Pliocene offshore well samples, caused by dissolution of apatite as sediments were uplifted and eroded onshore Sakhalin. These wells also show variable ATi and garnet–zircon index (GZi) values in Lower Miocene samples, which could potentially be used for stratigraphic correlation. A positive correlation between GZi values and distance from the river mouth is attributed to hydrodynamic sorting across the delta system. This has negative implications for the use of this stable mineral index and others of a similar hydraulic equivalence as regional correlation tools on a basin scale (>100 km). Supplementary material: Heavy mineral data, petrographic data, geochronometric data, sample locations available at www.geolsoc.org.uk/SUP18643 .

Abstract The Indo-Burman Ranges (IBR) represent an accretionary wedge, which is the result of subduction of the Indian plate beneath the Asian plate. In the Rakhine Coastal Belt it comprises a thick stack of Cretaceous to Neogene turbiditic sediments and localized thrust sheets of oceanic plate mafics and pelagic sediments. We investigate Eocene–Miocene sandstones, aiming to reveal the provenance of the detrital material using modal framework grain, heavy mineral and detrital zircon analysis (U–Pb laser ablation ICP-MS dating, Hf isotope geochemistry and typology). The results show a predominant derivation of the clastic material from: (i) Late Cretaceous to Oligocene igneous rocks, which are often bimodal with a low number of zircons spanning the Cretaceous–Palaeogene boundary, and (ii) recycled orogenic terrane sources comprising ophiolitic rocks. Age corrected Hf isotope ratios confirm subduction-related mixed mantle-crust sources. We also observe minor reworking of older magmatic zircons. By comparing our obtained petrographic parameters and zircon characteristics with potential Himalayan, Indian continent and Burman margin sources we conclude a Burman margin and arc origin provenance. With regard to hydrocarbon exploration in the IBR, a forearc and trench basin system model linked with the Burman arc appears more appropriate for evaluating the petroleum system. Supplementary material: sandstone modal composition, heavy mineral contents, detrital zircon U–Pb LA-ICPMS dating and hafnium results are available at http://www.geolsoc.org.uk/SUP18651 .

Abstract The heavy mineral compositions of sandstones in Trinidad and Barbados record the onset of Andean-related erosion and a reduction of craton-derived sediments into NE South America. The changing provenance was deduced by comparing heavy mineral assemblages interpreted from ancient sandstones with associations recognized in modern sands that can be reasonably correlated to existing tectonic domains. The impact of the Andean orogeny across the margin was to introduce a suite of minerals characteristic of low-temperature metamorphism that today is prevalent adjacent to the Caribbean Mountain belt and differs from the zircon-rich assemblage produced within cratonic plains. Twenty-one Paleocene–Late Pliocene sandstone samples from Trinidad revealed systematic changes in mineral diversity and maturity that recorded this provenance transition, and suggests Andean erosion during deposition of the Late Oligocene Nariva Formation. Similar to Palaeogene sandstones of Trinidad, four Eocene Scotland Formation samples from Barbados support craton derivation, but with additional evidence of minor Andean input probably due to the proximity of the Scotland Formation delivery systems to an earlier uplift episode. By the Late Miocene, most of the sediments delivered into Trinidad basins were supplied from the Andean orogeny as suggested by the relative abundance of minerals of this affinity. The heavy mineral records of Trinidad and Barbados are similar to that described across northern South America from both modern and ancient environments that collectively mark the uplift of the Andean mountain belt, with its strong influence on drainage patterns and reservoir provenance along this sector of the continental margin. Supplementary material: Sample location coordinates, sample and outcrop photographs, and summary outcrop sections are available at http://www.geolsoc.org.uk/SUP18728 .

Abstract Zircon U–Pb and rutile trace element data are used to investigate the provenance of late Devonian to early Permian terrestrial sandstones in the Embla and Flora oil fields on the north flank of the Mid North Sea High, central North Sea. Two Old Red Sandstone samples (ORS 1) are dominated by 1.2–0.9 Ga Grenvillian zircons and low- to medium-grade rutile, with sparse Cambro-Ordovician Caledonian zircons (2–4%) and high-grade rutiles (0–5%). The samples are interpreted as recycled metasediments from the Scottish Caledonides. Two other Old Red Sandstone samples (ORS 2) contain a high proportion of Caledonian, mainly Silurian zircons (15–19%) and high-grade rutiles (15–18%); we propose that these components are traceable to the Krummedal sequence on East Greenland (and related sediments). We interpret the data to reflect a temporal evolution of the regional drainage system from northwestern to northeastern sources, with high-grade detritus reaching the Mid North Sea High in the Famennian–early Carboniferous. A late Carboniferous and an early Permian sandstone yielded zircon and rutile signatures compatible with recycling of Palaeozoic sediments north of southernmost Scotland, probably reflecting inversion tectonics. Recycling of Mesoproterozoic to Palaeozoic sediments is thus a prominent feature of the studied late Palaeozoic sandstones. Supplementary material: Electron microprobe data from rutile trace element analyses, additional rutile temperature plots and zircon LA-ICPMS U–Pb data are available at http://www.geolsoc.org.uk/SUP18617 .

Abstract Detrital zircon U–Pb laser ablation inductively coupled plasma mass spectrometry age data on sandstones from Mesozoic successions on Svalbard are used to investigate provenance changes over time, constrain potential source areas, and to test and refine previous interpretations of the Mesozoic filling of the Barents Sea. The zircon age data indicate a western Laurentian (North Greenland) source in the Early and Middle Triassic. The westerly derived sediments most likely include reworked older sediments with proto-sources in Canada and Greenland. Sediments reaching Svalbard in the Late Triassic display a distinct Uralide signature that demonstrates derivation from the east. Zircon age populations in Late Triassic–Early Jurassic sands suggest mixing of zircons from the Early and Middle Triassic and Late Triassic sediments; the data are interpreted to reflect reworking of older Mesozoic sands and possible renewed input of sediments from the west. The data thus demonstrate a shift from westerly to easterly sediment sources in the early Late Triassic. The Early and Middle Triassic zircon age signature in this study appears to resurface in published Early Cretaceous provenance data from Svalbard, suggesting that sediment input from the east ceased during the Jurassic, and shifted back to westerly sources. Supplementary material: A summary of U–Pb isotopic results, Concordia diagrams of U–Pb age data, K–S test results and cumulative probability plots for all samples are available at www.geolsoc.org.uk/SUP18652 .

Abstract Combined U–Pb, Lu–Hf and O isotope data of detrital zircons from the Devonian sandstone of southern Libya provide important new boundary parameters for reconstruction of palaeosource areas and sediment transport and may lead to novel approaches to test current plate tectonic models, with important implications for our understanding of the evolution of northern Gondwana (in present-day coordinates) during the Palaeozoic. Detrital zircon U–Pb ages from Devonian sandstone of the eastern margin of the Murzuq Basin show four main age populations: 2.7–2.5 Ga (13%), 2.1–1.9 Ga (10%), 1.1–0.9 Ga (25%) and 0.7–0.5 Ga (46%). The ubiquitous occurrence of c. 1.0 Ga detrital zircons is characteristic of the Saharan Metacraton sedimentary cover sequence and provides new insights into palaeogeographic reconstructions of Gondwana-derived terranes in the Eastern Mediterranean and SW Europe. The Lu–Hf isotope data suggest that zircons crystallized within a narrow time interval from magmas with heterogeneous Hf isotope compositions. These magmas were derived by melting of pre-existing rocks, rather than being juvenile. The calculated Hf model ages range from 3.7 Ga to 1.3 Ga, with a major population between 2.8 Ga and 1.9 Ga, indicating prominent recycling of Archaean and Palaeoproterozoic crust.

Abstract Monazite geochronology was applied to an east–west transect of latest Jurassic and Lower Cretaceous deltaic sandstones of the Scotian Basin, to assess sediment sources and dispersal pathways. More than 200 detrital monazite grains yielded 694 electron microprobe age determinations with 1σ errors <±20%. Based on age, external morphology, zoning, inclusions and major element chemistry (rare earth element [REE], Th, Y), monazite grains represent more than 20 discrete sources. Similar proportions of euhedral and subhedral compared with irregular and rounded monazite grains in most age classes, together with comparison with detrital muscovite and zircon geochronology, suggest that most monazite is first cycle. Six types of REE distribution are recognized (A–F). Many igneous monazites show chemical zoning, contain sparse euhedral inclusions, and have REE distributions of types A and E. Many metamorphic monazites contain inclusions, commonly aligned, are generally rounded–subhedral to rounded, and have REE distributions of types B, C and D. Monazite geochronology shows important supply to the Scotian Basin from the Labrador rift shoulder as early as Tithonian; from Avalonian sources in the Tithonian; from Ordovician sources in northern New Brunswick, apparently via the Chaswood River; and from the inner continental shelf, particularly in the Hauterivian–Barremian.

Abstract The bulk geochemistry of 435 near-surface sediment samples from the southern Po Plain was used to identify the major sources of sediment delivered through distinct tracts of the routing system, from the Apenninic catchments to the Po Delta and the Adriatic coast. Sediment composition from the downstream reaches of the Po River and 23 Apenninic channel-levee river systems is fingerprinted by distinctive heavy metal (chromium and nickel) concentrations, which vary primarily as a function of the local ultramafic rock contribution. For any constant provenance domain, fine-grained (floodplain) sediments are invariably enriched in trace metals relative to their coarser-sized, channel-related counterparts, thus reflecting hydraulic sorting by crevasse and overbank processes. Once the geochemical signatures of fluvial endmembers are established, the relative contribution of the individual detrital sources to the downstream segments of the system can be assessed. Using an example from a multisourced supplied system, we outline the reconstruction of source-rock lithology and sediment pathways by combined sedimentological and geochemical studies as the basis for reliable estimates of sediment budgets in a source-to-sink context.