Holbourn, Ann E. L. et al. (1996): Onset of marine sedimentation in the Deep Ivorian Basin (ODP Site 962); evidence from Lower Cretaceous foraminifera

Leg/Site/Hole:
ODP 159
ODP 159 962
Identifier:
1997-048126
georefid

Creator:
Holbourn, Ann E. L.
Universitaet Kiel, Geologische-Palaeontologisches Institut, Kiel, Federal Republic of Germany
author

Moullade, Michel
Universite de Nice, France
author

Kuhnt, Wolfgang
author

Identification:
Onset of marine sedimentation in the Deep Ivorian Basin (ODP Site 962); evidence from Lower Cretaceous foraminifera
1996
In: Anonymous, Geological Society of America, 28th annual meeting
Geological Society of America (GSA), Boulder, CO, United States
28
7
119-120
Lower Cretaceous foraminiferal assemblages recovered from ODP Site 962 (leg 159) provide time constraints for the onset of marine sedimentation in the Deep Ivorian Basin and offer insights into the early palaeoenvironments of the Cote d'Ivoire-Ghana Transform Margin. Ninety-seven samples from a 270m mixed carbonate siliclastic unit at the base of Hole 962 are analysed. They contain upper Albian planktonic foraminifera, including Hedbergella delrioensis, Schackoina and Heterohelix spp., as well as abundant, small benthic foraminifera (less than 0.125mm), including various species of Berthelina, Gavelinella, Osangularia and Bolivina and diverse Nodosariids. Marked fluctuations in test size, abundance and diversity reflect a pulsed sedimentation pattern with an overall high accumulation rate, probably related to tectonic activity and to the close proximity of a rapidly subsiding margin. The intermittent occurrences of Patellinids, Miliolids and diatoms suggest that the sediment was periodically redeposited from a proximal, shallower source. The predominantly small size of benthic calcareous tests may be attributed to the granulometric sorting of allochthonous tests at a distal depositional setting above the CCD, and for autochthonous assemblages, to the prevalence of unfavourable dysoxic conditions on the seafloor, due to high accumulation rates. Both benthic and planktonic assemblages display some degree of endemism, which suggests that circulation was restricted in the basin during the late Albian and that connections with the Tethys were limited.
English
Coverage:Geographic coordinates:
North:75.0000
West:-80.0000East: 20.0000
South:-60.0000

Stratigraphy; anaerobic environment; assemblages; Atlantic; Atlantic Ocean; benthic taxa; Cenozoic; Cretaceous; Deep Ivorian Basin; Equatorial Atlantic; Foraminifera; granulometry; Holocene; Invertebrata; Leg 159; Lower Cretaceous; marine sedimentation; Mesozoic; microfossils; Ocean Drilling Program; ODP Site 962; paleoenvironment; patterns; planktonic taxa; Protista; provenance; Quaternary; sedimentation; sedimentation rates; siliciclastics; sorting; subsidence; tectonics;

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