The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform
Thierry Adatte - One of the best experts on this subject based on the ideXlab platform.
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Age, stratigraphy, and Deposition of near-K/T Siliciclastic Deposits in Mexico: Relation to bolide impact?
Geological Society of America Bulletin, 1997Co-Authors: Gerta Keller, Jose G. Lopez-oliva, Wolfgang Stinnesbeck, Thierry AdatteAbstract:Examination of 10 K/T boundary sections in northeastern and east-central Mexico, and new data presented from 7 sections, permit the following conclusions. (1) The globally recognized K/T boundary and mass extinction in planktic foraminifera is stratigraphically above, and separated by a thin marl layer of Maastrichtian age, from the Siliciclastic Deposit that is commonly interpreted as a short-term (hours to days) K/T-impact–generated tsunami Deposit. A similar relationship between the K/T boundary and Siliciclastic or breccia Deposits is observed at Brazos River in Texas, Beloc in Haiti, and Poty Quarry in Brazil. (2) Stratigraphic control indicates that Deposition of the Siliciclastic member occurred sometime during the last 150 k.y. of the Maastrichtian, and ended at least several thousand years prior to the K/T boundary. (3) At least four discrete horizons of bioturbation have been observed within the Siliciclastic Deposit that indicate episodic colonization by invertebrates over an extended time period. (4) The glass- and spherule-rich unit, which has been linked to the Haiti spherule layer and the Chicxulub structure, is at the base of the Siliciclastic Deposit and thus significantly predates the K/T boundary event. The stratigraphic separation of the K/T boundary and Siliciclastic Deposits and the evidence of long-term Deposition between them, suggests the presence of two events: (1) a globally recognized K/T boundary (impact) event marked by Ir anomaly and the mass extinction, and (2) a Caribbean event (impact or volcanic and probably linked to the Chicxulub structure) that predates the K/T boundary and is marked by glass and Siliciclastic or breccia Deposits.
Amanj I Qaradaghi - One of the best experts on this subject based on the ideXlab platform.
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Siliciclastic Deposit of the nahr umr formation sedimentological and Depositional environment studies central and southern iraq
Arabian Journal of Geosciences, 2013Co-Authors: Moutaz A Aldabbas, Jassim Aljassim, Amanj I QaradaghiAbstract:The Depositional facies and environments were unraveling by studying 21 subsurface sections from ten oilfields in the central and southern Iraq and a large number of thin sections of the Nahr Umr (Siliciclastic Deposit) Formation (Albian). This formation is mainly composed of sandstone interlaminated with minor siltstone and shale, with occurrence of thin limestone beds. Nahr Umr Formation is subdivided into three lithostratigraphic units of variable thicknesses on the basis of lithological variations and log characters. Mineralogically and texturally, mature quartz arenite and sandstones are the common type of the Nahr Umr Formation. The sandstones are cemented by silica and calcite material and have had a complex digenetic history. Compaction, dissolution, and replacements are the main diagenetic processes. Prodelta, distal bar, distributary mouth bar, distributary channel, over bank, and tidal channel are the main Depositional environments recognized for the Nahr Umr Formation, within the studied wells. This formation was Deposited in shallow marine and fluvial–deltaic environments and exhibit progradational succession of facies. Eight sedimentary facies that have been identified in the Nahr Umr Formation include claystone lithofacies, claystone siltstone lithofacies, lenticular-bedded sandstone–mudstone lithofacies, wavy-bedded sandstone–mudstone lithofacies, flaser-bedded sandstone–mudstone lithofacies, parallel and cross lamination sandstone lithofacies, trough cross-bedded sandstone lithofacies, and planar cross-bedded sandstone lithofacies. The Depositional model of the Nahr Umr Formation environment was built based on the lithofacies association concepts.
Gerta Keller - One of the best experts on this subject based on the ideXlab platform.
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Age, stratigraphy, and Deposition of near-K/T Siliciclastic Deposits in Mexico: Relation to bolide impact?
Geological Society of America Bulletin, 1997Co-Authors: Gerta Keller, Jose G. Lopez-oliva, Wolfgang Stinnesbeck, Thierry AdatteAbstract:Examination of 10 K/T boundary sections in northeastern and east-central Mexico, and new data presented from 7 sections, permit the following conclusions. (1) The globally recognized K/T boundary and mass extinction in planktic foraminifera is stratigraphically above, and separated by a thin marl layer of Maastrichtian age, from the Siliciclastic Deposit that is commonly interpreted as a short-term (hours to days) K/T-impact–generated tsunami Deposit. A similar relationship between the K/T boundary and Siliciclastic or breccia Deposits is observed at Brazos River in Texas, Beloc in Haiti, and Poty Quarry in Brazil. (2) Stratigraphic control indicates that Deposition of the Siliciclastic member occurred sometime during the last 150 k.y. of the Maastrichtian, and ended at least several thousand years prior to the K/T boundary. (3) At least four discrete horizons of bioturbation have been observed within the Siliciclastic Deposit that indicate episodic colonization by invertebrates over an extended time period. (4) The glass- and spherule-rich unit, which has been linked to the Haiti spherule layer and the Chicxulub structure, is at the base of the Siliciclastic Deposit and thus significantly predates the K/T boundary event. The stratigraphic separation of the K/T boundary and Siliciclastic Deposits and the evidence of long-term Deposition between them, suggests the presence of two events: (1) a globally recognized K/T boundary (impact) event marked by Ir anomaly and the mass extinction, and (2) a Caribbean event (impact or volcanic and probably linked to the Chicxulub structure) that predates the K/T boundary and is marked by glass and Siliciclastic or breccia Deposits.
Moutaz A Aldabbas - One of the best experts on this subject based on the ideXlab platform.
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Siliciclastic Deposit of the nahr umr formation sedimentological and Depositional environment studies central and southern iraq
Arabian Journal of Geosciences, 2013Co-Authors: Moutaz A Aldabbas, Jassim Aljassim, Amanj I QaradaghiAbstract:The Depositional facies and environments were unraveling by studying 21 subsurface sections from ten oilfields in the central and southern Iraq and a large number of thin sections of the Nahr Umr (Siliciclastic Deposit) Formation (Albian). This formation is mainly composed of sandstone interlaminated with minor siltstone and shale, with occurrence of thin limestone beds. Nahr Umr Formation is subdivided into three lithostratigraphic units of variable thicknesses on the basis of lithological variations and log characters. Mineralogically and texturally, mature quartz arenite and sandstones are the common type of the Nahr Umr Formation. The sandstones are cemented by silica and calcite material and have had a complex digenetic history. Compaction, dissolution, and replacements are the main diagenetic processes. Prodelta, distal bar, distributary mouth bar, distributary channel, over bank, and tidal channel are the main Depositional environments recognized for the Nahr Umr Formation, within the studied wells. This formation was Deposited in shallow marine and fluvial–deltaic environments and exhibit progradational succession of facies. Eight sedimentary facies that have been identified in the Nahr Umr Formation include claystone lithofacies, claystone siltstone lithofacies, lenticular-bedded sandstone–mudstone lithofacies, wavy-bedded sandstone–mudstone lithofacies, flaser-bedded sandstone–mudstone lithofacies, parallel and cross lamination sandstone lithofacies, trough cross-bedded sandstone lithofacies, and planar cross-bedded sandstone lithofacies. The Depositional model of the Nahr Umr Formation environment was built based on the lithofacies association concepts.
Jose G. Lopez-oliva - One of the best experts on this subject based on the ideXlab platform.
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Age, stratigraphy, and Deposition of near-K/T Siliciclastic Deposits in Mexico: Relation to bolide impact?
Geological Society of America Bulletin, 1997Co-Authors: Gerta Keller, Jose G. Lopez-oliva, Wolfgang Stinnesbeck, Thierry AdatteAbstract:Examination of 10 K/T boundary sections in northeastern and east-central Mexico, and new data presented from 7 sections, permit the following conclusions. (1) The globally recognized K/T boundary and mass extinction in planktic foraminifera is stratigraphically above, and separated by a thin marl layer of Maastrichtian age, from the Siliciclastic Deposit that is commonly interpreted as a short-term (hours to days) K/T-impact–generated tsunami Deposit. A similar relationship between the K/T boundary and Siliciclastic or breccia Deposits is observed at Brazos River in Texas, Beloc in Haiti, and Poty Quarry in Brazil. (2) Stratigraphic control indicates that Deposition of the Siliciclastic member occurred sometime during the last 150 k.y. of the Maastrichtian, and ended at least several thousand years prior to the K/T boundary. (3) At least four discrete horizons of bioturbation have been observed within the Siliciclastic Deposit that indicate episodic colonization by invertebrates over an extended time period. (4) The glass- and spherule-rich unit, which has been linked to the Haiti spherule layer and the Chicxulub structure, is at the base of the Siliciclastic Deposit and thus significantly predates the K/T boundary event. The stratigraphic separation of the K/T boundary and Siliciclastic Deposits and the evidence of long-term Deposition between them, suggests the presence of two events: (1) a globally recognized K/T boundary (impact) event marked by Ir anomaly and the mass extinction, and (2) a Caribbean event (impact or volcanic and probably linked to the Chicxulub structure) that predates the K/T boundary and is marked by glass and Siliciclastic or breccia Deposits.