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![First thumbnail for: Normalograptus kufraensis , a new species of grapt...]()
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![Chronostratigraphy of the studied succession on Jabal Eghei, where four stratigraphic units are recognized. These comprise, in ascending stratigraphic order, the Hawaz, Mamuniyat and Tanezzuft formations and the Mesozoic sandstone (‘Nubian Sandstone’). Age constraints on the Hawaz Formation and ‘Nubian Sandstone’ are limited, but lithostratigraphic comparisons coupled with fossil occurrences, including wood fragments in the latter unit, allow Middle Ordovician and Jurassic ages to be assigned respectively (e.g. Bellini et al. 1991). The Mamuniyat Formation similarly is ill constrained in Jabal Eghei, whereas the Tanezzuft Formation contains graptolites of Hirnantian–Rhuddanian affinity (Page et al. 2013).]()
![Model illustrating the envisaged environmental setting of Jabal Eghei during the deposition of the lower part of the Tanezzuft Formation. Of note is (1) the presence of tidewater ice sheets in a marine basin (accounting for both the striated surface and the occurrence of lonestones that are interpreted as ice-rafted debris) and (2) the formation of MnO2 concretions by influx of glacial meltwaters. The presence of tidewater ice sheets is argued to preclude the development of anoxia in this shallow marine setting, hence restricting the preservation potential of organic material on the sea floor. The lack of U enrichment in the Tanezzuft Formation, when used as a proxy for former TOC values in mudrocks, suggests that organically enriched sediments were not deposited at Jabal Eghei.]()
![Typical outcrop of the Mamuniyat Formation in Jabal Eghei, where the formation is exclusively dominated by sandstone. (a) Humpback dunes overlain by antidunes, suggesting a waning flow signature during a jökulhlaup glacial flood (Lang & Winsemann 2013). (b) Chute and pool structures, capped by antidunes, implying a waning flow signature. These sedimentary structures are very typical of deposits of the Hirnantian glacial maximum, with broadly comparable facies recognized from southern Algeria, western Libya (Girard et al. 2012) and the Libyan–Egyptain border (Le Heron et al. 2010).]()
![Figure 3.]()
![(a) Geographical relief map of the wider investigated central-southern Libya. (b) The sketch map showing the distribution of the four main volcanic provinces in Libya and principal faults delineating the celestine-bearing Sirt Basin and Jabal Nuqau Volcanic Province (modified after Elshaafi and Gudmundsson, 2016). The Al Haruj Volcanic Province (#3) is situated on the southwestern margin of the Sirt Basin, central Libya. To the south is the Jabal Eghei or Jabal Nuqau Volcanic Province (#4). Other provinces are (#1) Gharayan Volcanic Province, and (#2) As Sawda Volcanic Province. (c) Panoramic view on Jebel Eghei rhyolite volcanic complex (photo taken from Kovačević et al., 2013; modified). (d) Basalts from Jebel Eghei area (Abdusahmin, 2020, modified). (e) Basalts from Al Haruj area (photos taken from Vasić and Sheriff, 2007; modified).]()
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![Figure 6.]()
![Figure 4.]()
![Map of Libya, showing the location of the two main intracratonic basins in southern Libya, namely the petroliferous Murzuq Basin, and the frontier Al Kufrah Basin. The location of Jabal Eghei, the study area of this paper, is highlighted, together with the main outcrop belts of Cambrian–Ordovician and Silurian strata.]()
![Photomicrograph and camera lucida drawing of the late Hirnantian or rhuddanian graptolite Normalograptus kufraensisPage et al. (2013) preserved as a part-pyritised carbonaceous compresssion in the graptolite-bearing bed of the Tanezzuft Formation at Jabal Eghei, western Al Kufrah Basin. Specimen CAM SM X.50191.6a. Scale bar = 1 mm.]()
![Figure 5.]()
![—North-south cross section of Sirte embayment from Gulf of Sirte to Jabal Eghei, shovying writers’ concept of stratigraphic and lithologic relations. Thicknesses and differences in lithologic character differ greatly within short distances. Thus, many thousand feet of Oligocene and Miocene clastic strata are present within a few miles of this section. Basal quartzite is probably more widespread than suggested by this drawing. No attempt has been made to show faults and consequent highly irregular topograiihy of basement floor.]()
![Newly recognized glacial features within the Tanezzuft Formation of Jabal Eghei. The stratigraphic position of these features is shown in Figure 4. (a) Soft-sediment striated surface, comprising streamlined ridges and grooves similar to those described elsewhere in Al Kufrah Basin within the Mamuniyat Formation (e.g. Le Heron & Howard 2010; Le Heron et al. 2010). (b) Circular concretions overgrowing and crosscutting the striations allow the hypothesis that the grooves are aeolian to readily be dismissed. (c) Further detail of striated surface, showing local evidence for crosscutting striations. (d) Micritic lonestone ‘floating’ within a siltstone bed, tentatively interpreted as a dropstone. Pencil 5 cm long.]()
![Basal sandy carbonate facies association. (a) Relationship between the topmost part of the Mamuniyat Formation and the Tanezzuft Formation in Jabal Eghei. The basal sandy carbonate facies association fills in hollows on the topmost surface of the Mamuniyat Formation sandstones beneath. This contact is clearly marked on the measured section in Figure 4, which encompasses all strata visible in this photograph. The Tanezzuft Formation forms the generally recessive topography in the middle distance to background, which is capped disconformably by the ‘Nubian Sandstone’ of probable Jurassic age (see Fig. 2 for chronostratigraphy). (b) Bioturbated, quartz-bearing grainstone. (c) Mottled grainstone to floatstone with clearly visible crinoid ossicles among the shell fragments. Pencil 5 cm long.]()
![Measured section straddling the Mamuniyat and Tanezzuft formations and the ‘Nubian Sandstone’ in Jabal Eghei. The curve to the right of the logged section shows gamma-ray values obtained using a GF-InstrumentsTM gamma-ray spectrometer on the outcrop, for 3 min count intervals. The U content is commonly taken as a direct and linear proxy for former total organic carbon enrichment (TOC) (e.g. Lüning & Kolonic 2003; Lüning et al. 2003). The curve does not illustrate that proxy TOC values were elevated at or near the base of the Tanezzuft Formation, as is observed elsewhere in North Africa, such as in the Ghat area of SW Libya (Lüning et al. 2003). A simple interpretation (high versus low) of relative sea level, ice and anoxia is also shown. This relative sea-level curve takes into account the progressive upsection loss of hummocky cross-stratification and increase in mud content, compatible with a deepening trend. Ice presence is interpreted on the basis of soft-sediment striae and/or lonestones and manganese oxide concretions. Anoxia is inferred on the basis of faunal preservation in the graptolite assemblage (Page et al. 2013), with more oxic conditions indicated by the presence of bioturbation and manganese nodules.]()
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Journal Article
Characterisation, axial anisotropy, and formation conditions of celestine minerals from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southeastern edge of the Sirt Basin, southern Libya: Constraints on the mineralogical geothermometer – ERRATUM Available to Purchase
Journal: Mineralogical Magazine
Published: 01 April 2024
Mineralogical Magazine (2024) 88 (2): 210.
... ‘the major celestines with the disregarded gypsum or anhydrite phases’ should be removed. The correct text is: celestine characterisation axial anisotropy formation conditions Jabal Eghei (Nuqay) volcanic province southern Libya erratum The publisher apologies for an error introduced...
Journal Article
Characterisation, axial anisotropy, and formation conditions of celestine minerals from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southeastern edge of the Sirt Basin, southern Libya: Constraints on the mineralogical geothermometer Available to Purchase
Journal: Mineralogical Magazine
Published: 28 November 2023
Mineralogical Magazine (2024) 88 (1): 1–18.
...Pavle Tančić; Maja Milošević; Darko Spahić; Bojan Kostić; Aleksandar Kremenović; Maja Poznanović-Spahić; Jovan Kovačević Abstract Five celestine crystals were sampled from the (palaeo)surface intervening between the late Miocene to Pleistocene basaltic sequences of the Jabal Eghei (Nuqay) volcanic...
FIGURES
Journal Article
Normalograptus kufraensis , a new species of graptolite from the western margin of the Kufra Basin, Libya Available to Purchase
Journal: Geological Magazine
Publisher: Cambridge University Press
Published: 11 February 2013
Geological Magazine (2013) 150 (4): 743–755.
...ALEX PAGE; GUIDO MEINHOLD; DANIEL P. LE HERON; MOHAMED ELGADRY Abstract Normalograptus kufraensis sp. nov. occurs as monospecific assemblages in the Tanezzuft Formation at the western margin of the Kufra Basin (Jabal Eghei), southern Libya. These graptolites have parallel-sided rhabdosomes...
FIGURES
Image
Chronostratigraphy of the studied succession on Jabal Eghei, where four str... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 2. Chronostratigraphy of the studied succession on Jabal Eghei, where four stratigraphic units are recognized. These comprise, in ascending stratigraphic order, the Hawaz, Mamuniyat and Tanezzuft formations and the Mesozoic sandstone (‘Nubian Sandstone’). Age constraints on the Hawaz
Image
Model illustrating the envisaged environmental setting of Jabal Eghei durin... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 9. Model illustrating the envisaged environmental setting of Jabal Eghei during the deposition of the lower part of the Tanezzuft Formation. Of note is (1) the presence of tidewater ice sheets in a marine basin (accounting for both the striated surface and the occurrence of lonestones
Image
Typical outcrop of the Mamuniyat Formation in Jabal Eghei, where the format... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 3. Typical outcrop of the Mamuniyat Formation in Jabal Eghei, where the formation is exclusively dominated by sandstone. ( a ) Humpback dunes overlain by antidunes, suggesting a waning flow signature during a jökulhlaup glacial flood ( Lang & Winsemann 2013 ). ( b ) Chute and pool
Image
Shelly fossils from the Tanezzuft Formation in Jabal Eghei, western Kufra B... Available to Purchase
in Normalograptus kufraensis , a new species of graptolite from the western margin of the Kufra Basin, Libya
> Geological Magazine
Published: 11 February 2013
Figure 3. Shelly fossils from the Tanezzuft Formation in Jabal Eghei, western Kufra Basin. (a)
Brachiopod similar to ? Eocoelia X.50191.16. (b) Orthocone,
X.50191.17.
Image
(a) Geographical relief map of the wider investigated central-southern Liby... Available to Purchase
in Characterisation, axial anisotropy, and formation conditions of celestine minerals from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southeastern edge of the Sirt Basin, southern Libya: Constraints on the mineralogical geothermometer
> Mineralogical Magazine
Published: 28 November 2023
Elshaafi and Gudmundsson, 2016 ). The Al Haruj Volcanic Province (#3) is situated on the southwestern margin of the Sirt Basin, central Libya. To the south is the Jabal Eghei or Jabal Nuqau Volcanic Province (#4). Other provinces are (#1) Gharayan Volcanic Province, and (#2) As Sawda Volcanic Province. (c
Journal Article
Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya? Available to Purchase
Journal: Journal of the Geological Society
Publisher: Geological Society of London
Published: 01 March 2013
Journal of the Geological Society (2013) 170 (2): 327–339.
...Fig. 2. Chronostratigraphy of the studied succession on Jabal Eghei, where four stratigraphic units are recognized. These comprise, in ascending stratigraphic order, the Hawaz, Mamuniyat and Tanezzuft formations and the Mesozoic sandstone (‘Nubian Sandstone’). Age constraints on the Hawaz...
FIGURES
Image
Scatter plot of dorso-ventral widths (DVW) and two theca repeat distances (... Available to Purchase
in Normalograptus kufraensis , a new species of graptolite from the western margin of the Kufra Basin, Libya
> Geological Magazine
Published: 11 February 2013
Figure 6. Scatter plot of dorso-ventral widths (DVW) and two theca repeat distances (2TRD)
measured on Normalograptus kufraensis from the Lower Palaeozoic
succession of Jabal Eghei, western Kufra Basin.
Image
Photomicrographs of Normalograptus kufraensis sp. nov. from the ... Available to Purchase
in Normalograptus kufraensis , a new species of graptolite from the western margin of the Kufra Basin, Libya
> Geological Magazine
Published: 11 February 2013
Figure 4. Photomicrographs of Normalograptus kufraensis sp. nov. from the
graptolite-bearing bed of the Tanezzuft Formation in Jabal Eghei, western Kufra Basin.
Specimen numbers: (a) X.50191.10, (b) X.50191.6b, (c) X.50191.6a, (d) X.50191.13.
Scale bar
Image
Map of Libya, showing the location of the two main intracratonic basins in ... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 1. Map of Libya, showing the location of the two main intracratonic basins in southern Libya, namely the petroliferous Murzuq Basin, and the frontier Al Kufrah Basin. The location of Jabal Eghei, the study area of this paper, is highlighted, together with the main outcrop belts of Cambrian
Image
Photomicrograph and camera lucida drawing of the late Hirnantian or rhuddan... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 8. Photomicrograph and camera lucida drawing of the late Hirnantian or rhuddanian graptolite Normalograptus kufraensis Page et al . (2013) preserved as a part-pyritised carbonaceous compresssion in the graptolite-bearing bed of the Tanezzuft Formation at Jabal Eghei, western Al Kufrah
Image
Camera lucida drawings of Normalograptus kufraensis sp. nov. from ... Available to Purchase
in Normalograptus kufraensis , a new species of graptolite from the western margin of the Kufra Basin, Libya
> Geological Magazine
Published: 11 February 2013
Figure 5. Camera lucida drawings of Normalograptus kufraensis sp. nov. from
the graptolite-bearing bed of the Tanezzuft Formation in Jabal Eghei, western Kufra
Basin. Specimen numbers: (a) X.50191.6a, (b) X.50191.3c, holotype, (c) X.50191.1, (d)
X
Image
—North-south cross section of Sirte embayment from Gulf of Sirte to Jabal E... Available to Purchase
Published: 01 May 1967
Fig. 5. —North-south cross section of Sirte embayment from Gulf of Sirte to Jabal Eghei, shovying writers’ concept of stratigraphic and lithologic relations. Thicknesses and differences in lithologic character differ greatly within short distances. Thus, many thousand feet of Oligocene
Image
Newly recognized glacial features within the Tanezzuft Formation of Jabal E... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 6. Newly recognized glacial features within the Tanezzuft Formation of Jabal Eghei. The stratigraphic position of these features is shown in Figure 4 . ( a ) Soft-sediment striated surface, comprising streamlined ridges and grooves similar to those described elsewhere in Al Kufrah Basin
Image
Basal sandy carbonate facies association. ( a ) Relationship between the to... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 5. Basal sandy carbonate facies association. ( a ) Relationship between the topmost part of the Mamuniyat Formation and the Tanezzuft Formation in Jabal Eghei. The basal sandy carbonate facies association fills in hollows on the topmost surface of the Mamuniyat Formation sandstones beneath
Image
Measured section straddling the Mamuniyat and Tanezzuft formations and the ... Available to Purchase
in Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya?
> Journal of the Geological Society
Published: 01 March 2013
Fig. 4. Measured section straddling the Mamuniyat and Tanezzuft formations and the ‘Nubian Sandstone’ in Jabal Eghei. The curve to the right of the logged section shows gamma-ray values obtained using a GF-Instruments TM gamma-ray spectrometer on the outcrop, for 3 min count intervals. The U
Journal Article
Mineralogical Society of the UK and Ireland Free
Journal: Elements
Publisher: Mineralogical Society of America
Published: 01 February 2024
Elements (2024) 20 (1): 48–49.
..., Marco Pasero, Stuart J. Mills Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer Pavle Tan i , Maja Milo evi , Darko Spahi , Bojan Kosti...
Journal Article
Mineralogical Society of the UK and Ireland Free
Journal: Elements
Publisher: Mineralogical Society of America
Published: 01 April 2024
Elements (2024) 20 (2): 126–127.
..., Marco Pasero, Stuart J. Mills Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene Pleistocene volcanic province, southern Libya: constraints on the mineralogical geothermometer Pavle Tan i , Maja Milo evi , Darko Spahi , Bojan Kosti...
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