Marine osmium isotope record across the Cretaceous-Tertiary boundary ...

• Main Authors: Robinson, Nicole, Ravizza, Gregory E, Coccioni, Rodolfo, Peucker-Ehrenbrink, Bernhard, Norris, Richard D
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2009
• Subjects: Deep Sea Drilling Project DSDP; Ocean Drilling Program ODP; Pacific; Southern Ocean; South Atlantic Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.785723; https://doi.pangaea.de/10.1594/PANGAEA.785723

A composite late Maastrichtian (65.5 to 68.5 Ma) marine osmium (Os) isotope record, based on samples from the Southern Ocean (ODP Site 690), the Tropical Pacific Ocean (DSDP Site 577), the South Atlantic (DSDP Site 525) and the paleo-Tethys Ocean demonstrates that subaerially exposed pelagic carbonates can record seawater Os isotope variations with a fidelity comparable to sediments recovered from the seafloor. New results provide robust evidence of a 20% decline in seawater 187Os/188Os over a period of about 200 kyr early in magnetochron C29r well below the Cretaceous-Paleogene Boundary (KPB), confirming previously reported low-resolution data from the South Atlantic Ocean. New results also confirm a second more rapid decline in 187Os/188Os associated with the KPB that is accompanied by a significant increase in Os concentrations. Complementary platinum (Pt) and iridium (Ir) concentration data indicate that the length scale of diagenetic remobilization of platinum group elements from the KPB is less than 1 ... : Supplement to: Robinson, Nicole; Ravizza, Gregory E; Coccioni, Rodolfo; Peucker-Ehrenbrink, Bernhard; Norris, Richard D (2009): A high-resolution marine 187Os/188Os record for the late Maastrichtian: Distinguishing the chemical fingerprints of Deccan volcanism and the KP impact event. Earth and Planetary Science Letters, 281(3-4), 159-168 ...