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 - Publishing Network for Geoscientific and Environmental Data 1990
• Subjects: Antarc*; Antarctica; East Antarctica; Southern Ocean; Weddell Sea
• Online Access: https://dx.doi.org/10.15468/v89zzc; https://www.gbif.org/dataset/7d31187e-f762-11e1-a439-00145eb45e9a

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 ...