Distribution of benthic foraminifera in lower Cretaceous sediments of the Cuvuer Abyssal Plain in the Indian Ocean

Analysis of 66 samples from DSDP Site 263 (Cores 263-4R-4 to 263-29R-4) reveals a unique faunal composition with a predominance of agglutinated taxa, many of them previously unrecorded from any other DSDP and ODP Indian Ocean sites. A total of 66 agglutinated and 31 calcareous taxa are documented and five new species are described: Hippocrepina gracilis n.sp., "Textuluriopsis" elegans n.sp., Aaptotoichus challengeri n.sp., "Gaudryinopsis" pseudobettenstaedti n.sp. and "Gaudryina" cuvierensis n.sp. Three assemblages are recognized based on changes in the composition of dominant taxa and occurrences of stratigraphically important species: (1) a high-diversity Valanginian to Barremian Bulbobaculites-Recurvoides Assemblage (Cores 263-29R to - 18R), comprised of numerous elongate agglutinated forms, rare nodosariids, and variable numbers of tubes and ammodiscids; (2) a moderately diverse Aptian to Albian Rhizammina-Ammodiscus-Glomospira Assemblage (Cores 263-18R to -7R) with highly fluctuating numbers of the nominate taxa and Haplophragmoides, Trochammina, Verneuilinoides spp., and Verneuilina howchini; (3) a very low diversity Albian or younger Assemblage (Cores 263-6R to -4R) containing sparse agglutinated foraminifera, rare nodosariids and rotaliids. We interpret the assemblages as shelf to lower slope and consider them to reflect a deepening palaeobathymetry as the Cuvier margin subsided after the initial breakup of East Gondwana during the Valanginian. Our interpretation is in sharp contrast with initial palaeodepth estimates of less than 100 m, as well as with original chronostratigraphic interpretations based on foraminifera and nannofossils which correlated the base of the recovered interval with the Aptian. The absence of many cosmoplitan forms, despite high diversity suggests strong faunal differentiation in the Austral realm or endemisn within the Cuvier Basin during the Early Cretaceous.

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Holbourn, Ann E, Kaminski, Thomas (1995). Dataset: Distribution of benthic foraminifera in lower Cretaceous sediments of the Cuvuer Abyssal Plain in the Indian Ocean. https://doi.org/10.1594/PANGAEA.683648

DOI retrieved: 1995

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Imported on November 30, 2024
Last update November 30, 2024
License CC-BY-3.0
Source https://doi.org/10.1594/PANGAEA.683648
Author Holbourn, Ann E
Given Name Ann E
Family Name Holbourn
More Authors
Kaminski, Thomas
Source Creation 1995
Publication Year 1995
Resource Type application/zip - filename: Holbourn_benth_foram
Subject Areas
Name: Paleontology

Related Identifiers
Title: Lower Cretaceous benthic foraminifera from DSDP Site 263: micropalaeontological constraints for the early evolution of the Indian Ocean
Identifier: https://doi.org/10.1016/0377-8398(95)00011-9
Type: DOI
Relation: IsSupplementTo
Year: 1995
Source: Marine Micropaleontology
Authors: Holbourn Ann E , Kaminski Michael Anthony .