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Sherif Farouk - One of the best experts on this subject based on the ideXlab platform.
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the selandian Thanetian transition of the naqb el rufuf section kharga oasis western desert egypt foraminiferal biostratigraphy and sequence stratigraphy implications
Journal of African Earth Sciences, 2019Co-Authors: Abdel Galil A Hewaidy, Sherif Farouk, Youssef S BazeenAbstract:Abstract The Selandian-Thanetian (S/Th) succession is extensively represented and well exposed along the eastern escarpments of the Kharga Oasis, Western Desert, encompasses the upper part of the Dakhla Formation, Tarawan Formation and the lower part of the Esna Formation. This study based on the qualitative and quantitative investigation of the planktonic and benthic foraminiferal assemblages aims to assess and specify the S/Th transition in terms of the biostratigraphic, paleoecologic and sequence stratigraphic analyses. The studied interval is subdivided into three 3rd order depositional sequences (Seq. 1, Seq. 2 and Seq. 3) separated by two sequence boundaries at the Dakhla/Tarawan (SB 1) and the Tarawan/Esna (SB 2) contacts, respectively. The S/Th boundary is placed at the Maximum Flooding Surface (MFS) of the second depositional sequence (Seq. 2) within the Tarawan Formation and lies at about 6 m above the base of a distinct thin layer related to the Mid-Paleocene Biotic Event (MPBE). The S/Th MFS is characterized by a relatively highest positive peak in the P/B ratio (90%) and the common occurrence of the bathyal benthic taxa. The reported MFS displays great correspondence with the eustatic sea-level related to the timing and extent that can be treated as a secondary criterion relevant for delineating and correlating the Selandian-Thanetian transition everywhere.
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The Selandian/Thanetian transition of the Naqb El-Rufuf section, Kharga Oasis, Western Desert, Egypt: Foraminiferal biostratigraphy and sequence stratigraphy implications
Journal of African Earth Sciences, 2019Co-Authors: Abdel Galil A Hewaidy, Sherif Farouk, Youssef S BazeenAbstract:Abstract The Selandian-Thanetian (S/Th) succession is extensively represented and well exposed along the eastern escarpments of the Kharga Oasis, Western Desert, encompasses the upper part of the Dakhla Formation, Tarawan Formation and the lower part of the Esna Formation. This study based on the qualitative and quantitative investigation of the planktonic and benthic foraminiferal assemblages aims to assess and specify the S/Th transition in terms of the biostratigraphic, paleoecologic and sequence stratigraphic analyses. The studied interval is subdivided into three 3rd order depositional sequences (Seq. 1, Seq. 2 and Seq. 3) separated by two sequence boundaries at the Dakhla/Tarawan (SB 1) and the Tarawan/Esna (SB 2) contacts, respectively. The S/Th boundary is placed at the Maximum Flooding Surface (MFS) of the second depositional sequence (Seq. 2) within the Tarawan Formation and lies at about 6 m above the base of a distinct thin layer related to the Mid-Paleocene Biotic Event (MPBE). The S/Th MFS is characterized by a relatively highest positive peak in the P/B ratio (90%) and the common occurrence of the bathyal benthic taxa. The reported MFS displays great correspondence with the eustatic sea-level related to the timing and extent that can be treated as a secondary criterion relevant for delineating and correlating the Selandian-Thanetian transition everywhere.
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Shallow water agglutinated foraminiferal response to Late Cretaceous–Early Paleocene sea-level changes in the Dakhla Oasis, Western Desert, Egypt
Cretaceous Research, 2017Co-Authors: Sreepat Jain, Sherif FaroukAbstract:Abstract The Late Cretaceous (Maastrichtian) to early Paleocene (Thanetian) shallow water ( Haplophragmoides , Trochammina and Ammobaculites . Faunal changes at boundaries (Cretaceous/Paleogene, Danian/Selandian and Selandian/Thanetian) are also evaluated.
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sea level changes in the paleocene danian Thanetian succession at the dakhla oasis western desert egypt implications from benthic foraminifera
Proceedings of the Geologists' Association, 2017Co-Authors: Sherif Farouk, Sreepat JainAbstract:Abstract The Danian–Thanetian benthic foraminiferal assemblages at the Gharb El-Mawohb section in the Dakhla Oasis of Western Desert (Egypt) are inferred in combination with characteristic species, genera distribution, Benthic Foraminifera Numbers (BFN), species diversity, and abundance of high flux-species to infer prevailing paleoenvironment, paleoproductivity and paleobathymetry vis-a-vis sequence stratigraphy, regional tectonics, climate and changes in sea-level. The response of benthic foraminiferal assemblages to sea-level changes during boundary successions, namely the Danian/Selandian (D/S) and the Selandian/Thanetian (S/Th) is also analyzed. Data suggests a remarkably highly equitable environment throughout the studied interval. Eighty eight percent of the data plot in the restricted littoral environment (mostly in brackish and some in normal lagoons) suggesting that the fauna are not stressed despite a largely shallow depositional setting (middle to outer neritic, at places upper bathyal). The dominance of calcareous taxa indicates a largely open marine condition, in a largely oxic and oligotrophic environment, except in the late Paleocene where high-organic-flux species suggest increased paleoproductivity possibly due to local upwelling. The end of Zone P2 marks the deepest part of the studied section (outer neritic to upper bathyal) followed by gradual shallowing across the section (inner to middle neritic), with intermittent deepening in the middle of Zone P3a and P3b (middle neritic). There is shallowing at the transitions of Zones P3a, P3b and P4 (inner neritic). The changes in the vertical facies and benthic foraminiferal assemblage at the D/S and S/Th boundaries are analyzed.
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Sea-level changes in the Paleocene (Danian–Thanetian) succession at the Dakhla Oasis, Western Desert, Egypt: implications from benthic foraminifera
Proceedings of the Geologists' Association, 2017Co-Authors: Sherif Farouk, Sreepat JainAbstract:Abstract The Danian–Thanetian benthic foraminiferal assemblages at the Gharb El-Mawohb section in the Dakhla Oasis of Western Desert (Egypt) are inferred in combination with characteristic species, genera distribution, Benthic Foraminifera Numbers (BFN), species diversity, and abundance of high flux-species to infer prevailing paleoenvironment, paleoproductivity and paleobathymetry vis-a-vis sequence stratigraphy, regional tectonics, climate and changes in sea-level. The response of benthic foraminiferal assemblages to sea-level changes during boundary successions, namely the Danian/Selandian (D/S) and the Selandian/Thanetian (S/Th) is also analyzed. Data suggests a remarkably highly equitable environment throughout the studied interval. Eighty eight percent of the data plot in the restricted littoral environment (mostly in brackish and some in normal lagoons) suggesting that the fauna are not stressed despite a largely shallow depositional setting (middle to outer neritic, at places upper bathyal). The dominance of calcareous taxa indicates a largely open marine condition, in a largely oxic and oligotrophic environment, except in the late Paleocene where high-organic-flux species suggest increased paleoproductivity possibly due to local upwelling. The end of Zone P2 marks the deepest part of the studied section (outer neritic to upper bathyal) followed by gradual shallowing across the section (inner to middle neritic), with intermittent deepening in the middle of Zone P3a and P3b (middle neritic). There is shallowing at the transitions of Zones P3a, P3b and P4 (inner neritic). The changes in the vertical facies and benthic foraminiferal assemblage at the D/S and S/Th boundaries are analyzed.
Victoriano Pujalte - One of the best experts on this subject based on the ideXlab platform.
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the global stratotype sections and points for the bases of the selandian middle paleocene and Thanetian upper paleocene stages at zumaia spain
Episodes, 2011Co-Authors: Birger Schmitz, Victoriano Pujalte, Eustoquio Molina, Simonetta Monechi, Xabier Orueetxebarria, Robert P Speijer, Laia Alegret, Estibaliz Apellaniz, Ignacio Arenillas, Mariepierre AubryAbstract:The global stratotype sections and points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in the Basque Country, northern Spain. In the hemipelagic section exposed at Zumaia the base of the Selandian Stage has been placed at the base of the Itzurun Formation, ca. 49 m above the Cretaceous/ Paleogene boundary. At the base of the Selandian, marls replace the succession of Danian red limestone and limestone-marl couplets. The best marine, global correlation criterion for the basal Selandian is the second radiation of the important calcareous nannofossil group, the fasciculiths. Species such as Fasciculithus ulii, F. billii, F. janii, F. involutus, F. pileatus and F. Tympaniformis have their first appearance in the interval from a few decimetres below up to 1.1 m above the base of the Selandian. The marker species for nannofossil Zone NP5, F. tympaniformis , first occurs 1.1 m above the base. Excellent cyclostratigraphy and magnetostratigraphy in the section creates further correlation potential, with the base of the Selandian occuring 30 precession cycles (630 kyr) above the top of magnetochron C27n. Profound changes in sedimentology related to a major sea-level fall characterize the Danian-Selandian transition in sections along the margins of the North Atlantic. The base of the Thanetian Stage is placed in the same section ca. 78 m above the Cretaceous/Paleogene boundary. It is defined at a level 2.8 m or eight precession cycles above the base of the core of the distinct clay-rich interval associated with the Mid-Paleocene Biotic Event, and it corresponds to the base of magnetochron C26n in the section. The base of the Thanetian is not associated with any significant change in marine micro-fauna or flora. The calcareous nannofossil Zone NP6, marked by the first occurrence of Heliolithus kleinpelli starts ca. 6.5 m below the base of the Thanetian. The definitions of the global stratotype points for the bases of the Selandian and Thanetian stages are in good agreements with the definitions in the historical stratotype sections in Denmark and England, respectively.
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correlation of the Thanetian ilerdian turnover of larger foraminifera and the paleocene eocene thermal maximum confirming evidence from the campo area pyrenees spain
Geologica Acta, 2009Co-Authors: Victoriano Pujalte, Birger Schmitz, Xabier Orueetxebarria, Estibaliz Apellaniz, Jaume Dinaresturell, Juan Ignacio Baceta, Gilen Bernaola, Aitor Payros, F CaballeroAbstract:It has long been known that a major larger foraminifera turnover (LFT) occurred at the boundary between the Thanetian and Ilerdian stages, but its possible correlation with the Paleocene-Eocene thermal maximum (PETM) was unsuspected until the work of Baceta (1996), and has been controversial ever since. After summarizing the history of this controversy, we present information from three new sections that conclusively resolve the issue, all of them placed less than 2 km to the east of the classical Campo section in the southern Pyrenees. In these three sections, an up to 7 meter-thick intercalation of continental deposits rich in pedogenic carbonate nodules is sandwiched between uppermost Thanetian and lowermost Ilerdian shallow marine carbonates. The d13C composition of 42 pedogenic nodules collected from two of these sections (San Martin and La Cinglera) ranges between –11.4 and -14.3‰ and averages –12.9‰, values that conclusively represent the PETM and for the first time are recorded in sections where the LFT is clearly represented. Further, a high-resolution lithological correlation between Campo and the three new sections across the P-E interval unquestionably demonstrates that the lowermost marine beds with autochthonous specimens of Alveolina vredenburgi (a tell-tale of the LFT) are laterally interfingered –and are therefore coeval- with the nodule-bearing PETM continental deposits. On the basis of the new evidence, the temporal coincidence of the PETM and the LFT can no longer be doubted.
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closing the mid palaeocene gap toward a complete astronomically tuned palaeocene epoch and selandian and Thanetian gssps at zumaia basque basin w pyrenees
Earth and Planetary Science Letters, 2007Co-Authors: Jaume Dinaresturell, Xabier Orueetxebarria, Juan Ignacio Baceta, Gilen Bernaola, Victoriano PujalteAbstract:Abstract An integrated magneto-, bio- and cyclostratigraphic framework is presented for the Mid-Palaeocene interval from the (hemi)pelagic sea-cliff section of Zumaia in the Basque basin. The new ∼ 55 m long studied section expands about 3.5 Myr and closes the gap between previously published integrated studies in the section. The occurrence of magnetochron C26n is now documented, and its duration (complemented also by data from the Ibaeta section), and that for chrons C26r and C25r is estimated by counting precession related lithologic couplets assigned to have 21-kyr duration (C25r = ∼ 1449 kyr, C26n = ∼ 231 kyr, C26r = ∼ 2877 kyr). Consequently, the Zumaia section now provides the first complete Palaeocene astronomically derived chronology, rendering this section a master reference section. Due to limitations in the orbital calculations and uncertainties in the radiometric dating method no robust tuning and absolute ages can be given for the moment. However, the FOs (First Occurrences) of key calcareous plankton species and the Mid Palaeocene Biotic Event (MPBE) are placed within the magnetostratigraphic and cyclostratigraphic template along the studied Mid-Palaeocene interval. In addition, the dataset provides the key elements for a proper settling of the Thanetian and Selandian Global Stratotype Section and Point (GSSPs), which is one of the primary objectives of the ICS (International Commission of Stratigraphy). We consider the base of chron C26n and the criteria associated to the lithostratigraphic change between the Danian Limestone Fm and the Itzurun marl Fm at Zumaia, as the respective delimiting points for the Thanetian and Selandian bases as recently agreed by the Paleocene Working Group of the International Subcommission of the Paleogene Stratigraphy of the ICS. Consequently, the duration of the Thanetian, Selandian and Danian component stages can be estimated at Zumaia to be about ∼ 3129 kyr, ∼ 2163 kyr and ∼ 4324 kyr respectively (see text for error considerations). However, the MPBE located 8 precession cycles below the base of C26n in correspondence to a short eccentricity maxima at Zumaia, could also serve as a guiding criteria to approximate or redefine the Thanetian base if this level demonstrated synchronous.
Abdelbaset S Elsorogy - One of the best experts on this subject based on the ideXlab platform.
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Thanetian transgressive regressive sequences based on foraminiferal paleobathymetry at gebel matulla west central sinai egypt
Journal of African Earth Sciences, 2016Co-Authors: Sherif Farouk, Zaineb Elamri, Abdelbaset S ElsorogyAbstract:Abstract Qualitative and quantitative analysis of Thanetian foraminiferal assemblages at Gebel Matulla in west-central Sinai has been carried out. Three benthic foraminiferal assemblages are recorded from shallowest to deepest as Cibicidoides pseudoacutus , Angulogavelinella avnimelechi , Gavelinella danica witch evidences of fluctuations from middle neritic to upper bathyal environments. Changes in the foraminiferal population enabled us to classify the Thanetian succession into two fourth order transgressive-regressive (T–R) sequences. Three sequence boundaries are identified, at the Selandian/Thanetian (S/T) boundary, within the Thanetian succession, and the Paleocene/Eocene (P/E) boundary. It occurs at the top part of the maximum regression associated with major discontinuities and changes in depositional regimes as well as vertical facies changes. Broad correlation with eustatic records based upon integrated microplanktonic biostratigraphy suggests that the fluctuations of foraminiferal population were controlled by global sea-level changes.
Clinton P Conrad - One of the best experts on this subject based on the ideXlab platform.
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no global scale transgressive regressive cycles in the Thanetian paleocene evidence from interregional correlation
Palaeogeography Palaeoclimatology Palaeoecology, 2010Co-Authors: Dmitry A Ruban, Svetlana O Zorina, Clinton P ConradAbstract:Abstract A detailed examination of transgressions and regressions that occurred during the Thanetian (58.7–55.8 Ma) may provide an important constraint on the global palaeoenvironment. Seven tectonically “stable” regions (the eastern Russian Platform, Northwestern Europe, Northwestern Africa, Northeastern Africa, the Arabian Platform, the northern Gulf of Mexico, and Southern Australia), represent exceptional records of transgressive–regressive (T–R) cyclicity. Their chronostratigraphic frameworks are sufficiently well constrained to permit accurate correlation. Surprisingly, except for a generally regressive trend occurring in the late Thanetian, no common T–R cycles can be delineated, which indicates an absence of global-scale T–R cyclicity during the Thanetian. Furthermore, we find no clear correspondence between documented T–R patterns and previously reported eustatic changes. We suggest that a warm climate and an absence of major glaciations in the early-middle Thanetian, coupled with only slow eustatic change expected from tectonic processes, stabilized Thanetian eustatic sea level. Regional subsidence or uplift, possibly generated by mantle flow in the form of dynamic topography, governed transgressions and regressions locally and resulted in an inconsistency between T–R cycles in different parts of the globe. The late Thanetian regressive episode, which preceded the Paleocene–Eocene Thermal Maximum, may be linked to an advance of glaciation.
Xabier Orueetxebarria - One of the best experts on this subject based on the ideXlab platform.
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the global stratotype sections and points for the bases of the selandian middle paleocene and Thanetian upper paleocene stages at zumaia spain
Episodes, 2011Co-Authors: Birger Schmitz, Victoriano Pujalte, Eustoquio Molina, Simonetta Monechi, Xabier Orueetxebarria, Robert P Speijer, Laia Alegret, Estibaliz Apellaniz, Ignacio Arenillas, Mariepierre AubryAbstract:The global stratotype sections and points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in the Basque Country, northern Spain. In the hemipelagic section exposed at Zumaia the base of the Selandian Stage has been placed at the base of the Itzurun Formation, ca. 49 m above the Cretaceous/ Paleogene boundary. At the base of the Selandian, marls replace the succession of Danian red limestone and limestone-marl couplets. The best marine, global correlation criterion for the basal Selandian is the second radiation of the important calcareous nannofossil group, the fasciculiths. Species such as Fasciculithus ulii, F. billii, F. janii, F. involutus, F. pileatus and F. Tympaniformis have their first appearance in the interval from a few decimetres below up to 1.1 m above the base of the Selandian. The marker species for nannofossil Zone NP5, F. tympaniformis , first occurs 1.1 m above the base. Excellent cyclostratigraphy and magnetostratigraphy in the section creates further correlation potential, with the base of the Selandian occuring 30 precession cycles (630 kyr) above the top of magnetochron C27n. Profound changes in sedimentology related to a major sea-level fall characterize the Danian-Selandian transition in sections along the margins of the North Atlantic. The base of the Thanetian Stage is placed in the same section ca. 78 m above the Cretaceous/Paleogene boundary. It is defined at a level 2.8 m or eight precession cycles above the base of the core of the distinct clay-rich interval associated with the Mid-Paleocene Biotic Event, and it corresponds to the base of magnetochron C26n in the section. The base of the Thanetian is not associated with any significant change in marine micro-fauna or flora. The calcareous nannofossil Zone NP6, marked by the first occurrence of Heliolithus kleinpelli starts ca. 6.5 m below the base of the Thanetian. The definitions of the global stratotype points for the bases of the Selandian and Thanetian stages are in good agreements with the definitions in the historical stratotype sections in Denmark and England, respectively.
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correlation of the Thanetian ilerdian turnover of larger foraminifera and the paleocene eocene thermal maximum confirming evidence from the campo area pyrenees spain
Geologica Acta, 2009Co-Authors: Victoriano Pujalte, Birger Schmitz, Xabier Orueetxebarria, Estibaliz Apellaniz, Jaume Dinaresturell, Juan Ignacio Baceta, Gilen Bernaola, Aitor Payros, F CaballeroAbstract:It has long been known that a major larger foraminifera turnover (LFT) occurred at the boundary between the Thanetian and Ilerdian stages, but its possible correlation with the Paleocene-Eocene thermal maximum (PETM) was unsuspected until the work of Baceta (1996), and has been controversial ever since. After summarizing the history of this controversy, we present information from three new sections that conclusively resolve the issue, all of them placed less than 2 km to the east of the classical Campo section in the southern Pyrenees. In these three sections, an up to 7 meter-thick intercalation of continental deposits rich in pedogenic carbonate nodules is sandwiched between uppermost Thanetian and lowermost Ilerdian shallow marine carbonates. The d13C composition of 42 pedogenic nodules collected from two of these sections (San Martin and La Cinglera) ranges between –11.4 and -14.3‰ and averages –12.9‰, values that conclusively represent the PETM and for the first time are recorded in sections where the LFT is clearly represented. Further, a high-resolution lithological correlation between Campo and the three new sections across the P-E interval unquestionably demonstrates that the lowermost marine beds with autochthonous specimens of Alveolina vredenburgi (a tell-tale of the LFT) are laterally interfingered –and are therefore coeval- with the nodule-bearing PETM continental deposits. On the basis of the new evidence, the temporal coincidence of the PETM and the LFT can no longer be doubted.
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closing the mid palaeocene gap toward a complete astronomically tuned palaeocene epoch and selandian and Thanetian gssps at zumaia basque basin w pyrenees
Earth and Planetary Science Letters, 2007Co-Authors: Jaume Dinaresturell, Xabier Orueetxebarria, Juan Ignacio Baceta, Gilen Bernaola, Victoriano PujalteAbstract:Abstract An integrated magneto-, bio- and cyclostratigraphic framework is presented for the Mid-Palaeocene interval from the (hemi)pelagic sea-cliff section of Zumaia in the Basque basin. The new ∼ 55 m long studied section expands about 3.5 Myr and closes the gap between previously published integrated studies in the section. The occurrence of magnetochron C26n is now documented, and its duration (complemented also by data from the Ibaeta section), and that for chrons C26r and C25r is estimated by counting precession related lithologic couplets assigned to have 21-kyr duration (C25r = ∼ 1449 kyr, C26n = ∼ 231 kyr, C26r = ∼ 2877 kyr). Consequently, the Zumaia section now provides the first complete Palaeocene astronomically derived chronology, rendering this section a master reference section. Due to limitations in the orbital calculations and uncertainties in the radiometric dating method no robust tuning and absolute ages can be given for the moment. However, the FOs (First Occurrences) of key calcareous plankton species and the Mid Palaeocene Biotic Event (MPBE) are placed within the magnetostratigraphic and cyclostratigraphic template along the studied Mid-Palaeocene interval. In addition, the dataset provides the key elements for a proper settling of the Thanetian and Selandian Global Stratotype Section and Point (GSSPs), which is one of the primary objectives of the ICS (International Commission of Stratigraphy). We consider the base of chron C26n and the criteria associated to the lithostratigraphic change between the Danian Limestone Fm and the Itzurun marl Fm at Zumaia, as the respective delimiting points for the Thanetian and Selandian bases as recently agreed by the Paleocene Working Group of the International Subcommission of the Paleogene Stratigraphy of the ICS. Consequently, the duration of the Thanetian, Selandian and Danian component stages can be estimated at Zumaia to be about ∼ 3129 kyr, ∼ 2163 kyr and ∼ 4324 kyr respectively (see text for error considerations). However, the MPBE located 8 precession cycles below the base of C26n in correspondence to a short eccentricity maxima at Zumaia, could also serve as a guiding criteria to approximate or redefine the Thanetian base if this level demonstrated synchronous.
