Eocene benthic foraminifera of DSDP Hole 93-605@en

This paper describes and illustrates early to middle Eocene benthic foraminifers from northwest Atlantic Site 605, on the continental rise off New Jersey. Benthic foraminiferal faunas are dominated by Bulitnina spp., Nuttallides truempyi, Lenticulina spp., and Cibicidoides spp. Other common taxa include Oridorsalis spp., Gyroidinoides spp., uniserial taxa, arenaceous taxa, and Globocassidulina subglobosa. Together, these taxa usually make up 70% or more of the total fauna. The assemblages are interpreted as indicating a lower bathyal environment of deposition during the Eocene at Site 605. This is corroborated by an independent water depth estimate through backstripping, indicating a water depth for the beginning of the Eocene to late middle Eocene of approximately 2300 to 2000 m.本论文描述并阐明了大西洋西北部新泽西外大陆隆（continental rise）605站位（Site 605）的始新世早中期底栖有孔虫（benthic foraminifers）。该底栖有孔虫动物群以Bulitnina属种（Bulitnina spp.）、Nuttallides truempyi、Lenticulina属种（Lenticulina spp.）以及Cibicidoides属种（Cibicidoides spp.）为优势类群。其他常见类群包括Oridorsalis属种（Oridorsalis spp.）、Gyroidinoides属种（Gyroidinoides spp.）、单列壳类群、砂质壳类群以及Globocassidulina subglobosa。上述类群合计通常占总动物群的70%以上。该有孔虫组合被解读为指示605站位在始新世时期处于下半深海沉积环境。这一结论通过地层回剥法（backstripping）得到的独立水深估算结果得到佐证，该估算显示始新世早期至中始新世晚期的水深约为2300米至2000米。