Mid-Pliocene deep-sea bottom-water temperatures based on ostracode Mg/Ca ratios

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doi: 10.1016/j.marmicro.2004.12.003
Author(s): Cronin, Thomas M.; Dowsett, Harry J.; Dwyer, Gary S.; Baker, Paul A.; Chandler, Mark A.
Author Affiliation(s): Primary:
U. S. Geological Survey, Reston, VA, United States
Duke University, United States
Goddard Institute for Space Studies, United States
Volume Title: Marine Micropaleontology
Source: Marine Micropaleontology, 54(3-4), p.249-261. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. 93 refs.; illus., incl. 1 table, sketch map
Summary: We studied magnesium:calcium (Mg/Ca) ratios in shells of the deep-sea ostracode genus Krithe from a short interval in the middle Pliocene between 3.29 and 2.97 Ma using deep-sea drilling sites in the North and South Atlantic in order to estimate bottom water temperatures (BWT) during a period of climatic warmth. Results from DSDP and ODP Sites 552A, 610A, 607, 658A, 659A, 661A and 704 for the period Ma reveal both depth and latitudinal gradients of mean Mg/Ca values. Shallower sites (552A, 610A and 607) have higher mean Mg/Ca ratios (10.3, 9.7, 10.1 mmol/mol) than deeper sites (661A, 6.3 mmol/mol), and high latitude North Atlantic sites (552A, 610A, 607) have higher Mg/Ca ratios than low latitude (658A: 9.8 mmol/mol, 659A: 7.7 mmol/mol, 661A: 6.3 mmol/mol) and Southern Ocean (704: 8.0 mmol/mol) sites. Converting Mg/Ca ratios into estimated temperatures using the calibration of Dwyer et al. (1995) [Dwyer, G. S., Cronin, T. M., Baker, P. A., Raymo, M. E., Buzas, J. S., Correge, T., 1995. North Atlantic deepwater temperature change during late Pliocene and late Quaternary climatic cycles. Science 270, 1347-1351] suggests that mean middle Pliocene bottom water temperatures at the study sites in the deep Atlantic were about the same as modern temperatures. However, brief pulses of elevated BWT occurred several times between 3.29 and 2.97 Ma in both the North and South Atlantic Ocean suggesting short-term changes in deep ocean circulation. Abstract Copyright (2005) Elsevier, B.V.
Year of Publication: 2005
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Arthropoda; Atlantic Ocean; Calcium; Cenozoic; Chemical ratios; Crustacea; Deep Sea Drilling Project; Deep-sea environment; Invertebrata; Magnesium; Mandibulata; Marine environment; Metals; Mg/Ca; Microfossils; Middle Pliocene; Neogene; Ocean Drilling Program; Ostracoda; Paleo-oceanography; Paleotemperature; Pliocene; Reconstruction; Shells; Tertiary
Record ID: 2006012614
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

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