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Mesozoic global environments


Coffin, MF, Mesozoic global environments, CHIKYU+10 International Workshop Report, 21-23 April 2013, Tokyo, Japan, pp. WP-45. (2013) [Refereed Conference Paper]


Old oceans have disappeared and new oceans have been created repeatedly in Earth history. Associated changes in continental distribution, oceanic circulation, and episodic magmatism (large igneous provinces) have been implicated in altering paleoclimate, paleoceanography, and sea level, as well as in forcing biological changes. In Cretaceous time, the two major oceans—Tethys and the Pacific—differed enormously. Prior to Aptian time, Tethys was characterized by massive carbonate deposition, whereas radiolarian clays dominated the Pacific. In mid-Cretaceous time, Tethyan waters contained little oxygen, as recorded by black shales, whereas deep Pacific waters were well oxygenated. We seek to understand why these oceans differed in Mesozoic time, as well as more generally to determine the climatic process(es) that operated in Cretaceous time, the mechanism(s) that sustained the extremely warm Greenhouse Earth, and the process or event that terminated the Greenhouse climatic pattern (eg, cessation of global circum-equatorial circulation). Specific goals in studying the Mesozoic sedimentary record in the ocean are to investigate: the dominant Milankovitch frequencies during the Greenhouse; the operation of and variation in biogeochemical cycles; the effects of evolution, radiations, and extinctions on carbonate cycling; the variation in locus of carbonate cycling and budgets between continental shelves and the open ocean; the variation of the carbonate compensation depth (CCD); the balance between oceanic and continental chemical fluxes; and the history of and processes affecting oxygenation, in particular oceanic anoxic events (OAEs). Drilling is the only means of obtaining the detailed Mesozoic sedimentary sections necessary to understand Mesozoic global environments, and environmental changes and their causes. Optimal site selection for attaining the scientific objectives of drilling Mesozoic sedimentary sections will require extensive regional 2D and local 3D multichannel and wide-angle seismic control of a quality and scale currently typical only in areas of intensive hydrocarbon exploration.

Item Details

Item Type:Refereed Conference Paper
Keywords:paleoceanography, paleoclimate, greenhouse Earth, large igneous provinces, oceanic anoxic events, Mesozoic
Research Division:Earth Sciences
Research Group:Geology
Research Field:Marine Geoscience
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Coffin, MF (Professor Mike Coffin)
ID Code:116456
Year Published:2013
Funding Support:Australian Research Council (LE140100047)
Deposited By:Oceans and Cryosphere
Deposited On:2017-05-10
Last Modified:2018-07-11

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