The calcareous nannofossil response to the end-Cretaceous warm event in the tropical Pacific

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doi: 10.1016/j.palaeo.2010.02.036
Author(s): Thibault, Nicolas; Gardin, Silvia
Author Affiliation(s): Primary:
University of Copenhagen, Department of Geography and Geology, Copenhagen, Denmark
Other:
Université Pierre et Marie Curie-Paris VI, France
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 291(3-4), p.239-252. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. Supplemental information/data is available in the online version of this article. 92 refs.; illus., incl. charts, 4 tables, sketch map
Summary: The response of calcareous nannofossils to the end-Cretaceous warming is investigated in the Tropical Pacific DSDP Site 577A (Shatsky Rise) through the record of species richness, Shannon diversity, distribution patterns and statistical treatments. This event is marked by a strong acme of the tropical species Micula murus and is accompanied by a decrease of Placozygus spiralis, the disappearance of Biscutum constans and a decrease in bulk δ13C, indicative of a decrease in primary productivity. An increase in abundance of other Micula species at Site 577A and a drop in species richness recorded in all sites of Shatsky Rise, suggest stressed environmental conditions coincident with the end-Cretaceous warming. The acme of M. murus at Shatsky Rise and in the Atlantic Ocean is recorded within magnetochron C29r and correlates (1) with the intense warming as expressed in intermediate waters through the δ18O of benthic foraminifera, and in surface waters through poleward migration, reduced diversity and dwarfism in planktonic foraminifer assemblages, (2) with a sharp decline in marine 187Os/188Os, chemical marker of Deccan volcanic activity, and (3) with a rise in the atmospheric pCO2 record of terrestrial plants in Texas, USA, probably triggered by Deccan volcanic degassing. However, a drop of calcareous nannofossil cool-water taxa in the Equatorial and South Atlantic, as well as a first rise in abundance of M. murus in the South Atlantic and Tropical Pacific occur in the topmost part of chron C30n, and correlates with the rise in palaeotemperature record of terrestrial plants in North Dakota, USA. This suggests that initiation of the warming in the atmosphere and surface waters may predate the striking warming of intermediate water masses by 150/200 kyr. The coincidence and the links between climate change, volcanism, geochemical and biotic events at the end of the Maastrichtian thus remain to be fully elucidated. Abstract Copyright (2010) Elsevier, B.V.
Year of Publication: 2010
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Atlantic Ocean; Biodiversity; Climate change; Correlation; Cretaceous; DSDP Site 577; Deccan Traps; Deep Sea Drilling Project; Degassing; Foraminifera; Geochemistry; IPOD; Invertebrata; Isotope ratios; Isotopes; Leg 86; Maestrichtian; Marine environment; Mesozoic; Microfossils; Nannofossils; North Pacific; Northwest Pacific; O-18/O-16; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoatmosphere; Paleoclimatology; Paleoecology; Plantae; Productivity; Protista; Senonian; Shatsky Rise; Stable isotopes; Statistical analysis; Tropical environment; Upper Cretaceous; Upper Maestrichtian; Volcanism; West Pacific
Coordinates: N322628 N322632 E1574324 E1574323
Record ID: 2010077160
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands