A high-resolution marine 187Os/188Os record for the late Maastrichtian; distinguishing the chemical fingerprints of Deccan volcanism and the KP impact event

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doi: 10.1016/j.epsl.2009.02.019
Author(s): Robinson, Nicole; Ravizza, Greg; Coccioni, Rodolfo; Peucker-Ehrenbrink, Bernhard; Norris, Reichard
Author Affiliation(s): Primary:
University of Hawaii at Manoa, Department of Geology and Geophysics, Honolulu, HI, United States
Other:
Universita degli Studi "Carlo Bo", Italy
Woods Hole Oceanographic Institution, United States
Scripps Institute of Oceanography, United States
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 281(3-4), p.159-168. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. Supplemental information/data is available in the online version of this article. 65 refs.; illus., incl. 2 tables
Summary: 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 m and does not obscure the pre-KPB decline in 187Os/188Os. Increases in bulk sediment Ir concentrations and decreases in bulk carbonate content that coincide with the Os isotope shift suggest that carbonate burial flux may have been lower during the initial decline in 187Os/188Os. We speculate that diminished carbonate burial rate may have been the result of ocean acidification caused by Deccan volcanism. Abstract Copyright (2009) Elsevier, B.V.
Year of Publication: 2009
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Acidification; Atlantic Ocean; Basalts; Burial; Carbonate rocks; Cenozoic; Correlation; Cretaceous; DSDP Site 525; DSDP Site 577; Deccan Traps; Deep Sea Drilling Project; Diagenesis; Flood basalts; ICP mass spectra; IPOD; Igneous rocks; Impacts; Iridium; Isotope ratios; Isotopes; K-T boundary; Leg 113; Leg 74; Leg 86; Lower Paleocene; Maestrichtian; Marine environment; Mass spectra; Maud Rise; Mesozoic; Metals; Mobilization; North Pacific; Northwest Pacific; ODP Site 690; Ocean Drilling Program; Os-188/Os-187; Osmium; Pacific Ocean; Paleocene; Paleoenvironment; Paleogene; Paleotethys; Pelagic environment; Platinum; Platinum group; Sea water; Sedimentary rocks; Senonian; Shatsky Rise; South Atlantic; Southern Ocean; Spectra; Stable isotopes; Stratigraphic boundary; Tertiary; Upper Cretaceous; Volcanic rocks; Volcanism; Walvis Ridge; Weddell Sea; West Pacific
Coordinates: S290415 S290414 E0025908 E0025907
N322628 N322632 E1574324 E1574323
S650938 S650937 E0011218 E0011218
Record ID: 2009080652
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands