Abundance of calcareous nannofossils across the K/T boundary at ODP Hole 113-690C (Table 1) ...

• Main Authors: Pospichal, James J, Wise, Sherwood W
• Format: Dataset
• Language: English
• Published: PANGAEA 1990
• Subjects: Epoch; Nannofossil zone; Sample code/label; DEPTH, sediment/rock; Biantholithus sparsus; Cruciplacolithus primus; Hornibrookina edwardsii; Biscutum castrorum; Cyclagelosphaera reinhardtii; Lapideacassis sp.; Markalius inversus; Neocrepidolithus spp.; Thoracosphaera spp.; Zygodiscus sigmoides; Acuturris scotus; Ahmuellerella octoradiata; Arkhangelskiella spp.; Chiastozygus sp.; Cretarhabdus conicus; Cribrosphaerella daniae; Cribrosphaerella ehrenbergii; Eiffellithus turriseiffelii; Gartnerago spp.; Kamptnerius magnificus; Micula decussata; Nephrolithus frequens; Prediscosphaera cretacea; Prediscosphaera spinosa; Prediscosphaera stoveri; Nannofossils, tertiary; Nannofossils, survivor; Nannofossils, cretaceous; Nannofossils; Drilling/drill rig; DSDP/ODP/IODP sample designation; Smear slide analysis; Leg113; Joides Resolution; Ocean Drilling Program ODP; Antarc*; Antarctica; East Antarctica; Southern Ocean; Weddell Sea
• Online Access: https://dx.doi.org/10.1594/pangaea.746448; https://doi.pangaea.de/10.1594/PANGAEA.746448

A biostratigraphically continuous, but intensely bioturbated, Cretaceous/Tertiary boundary sequence was cored during Ocean Drilling Program (ODP) Leg 113 on Maud Rise (65°S) in the Weddell Sea off East Antarctica. This interval is the first recovered by ODP/DSDP in the South Atlantic sector of the Southern Ocean and offers a unique opportunity to study the nannofossil sequences leading up to and beyond the terminal Cretaceous event at a high southern latitude.The K/T boundary lies just within Chron 29R and is placed at ODP Sample 113-690C-15X-4, 41.5 cm. An iridium anomaly was independently noted at about this level as well. Upper Maestrichtian-lower Paleocene sediments consist mostly of light-colored nannofossil chalks. Dark brown sediments at the base of the Danian (Zone CPla) are characterized by an increased clay content attributed to a drop in calcareous microplankton productivity following the terminal Cretaceous event.Although delineation of the boundary is hampered by intense bioturbation, the sharp ... : <1 = present, but not noted within count of 500 specimens. ...