Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Phanerozoic record of plate tectonic control of seawater chemistry and carbonate sedimentation

Thomas Steuber and Jan Veizer
Phanerozoic record of plate tectonic control of seawater chemistry and carbonate sedimentation
Geology (Boulder) (December 2002) 30 (12): 1123-1126

Abstract

Sr concentrations in Phanerozoic biological calcite suggest a close link between fluctuations in the Sr/Ca ratio of seawater, aragonite versus calcite sedimentation, and the Mg/Ca ratio of seawater, the entire chain being driven by the rate of production and hydrothermal alteration of the oceanic crust. Model simulations suggest that variations in hydrothermal and continental weathering fluxes cannot be the sole reason for the observed Phanerozoic seawater Sr/Ca trend. Changing Sr burial in marine carbonates is likely the most important mechanism that can explain the experimental data. During episodes of high seawater Mg/Ca ratios, aragonite was preferentially deposited, resulting in low seawater Sr/Ca ratios. At low Mg/Ca ratios, calcite was the dominant carbonate sediment, and the Sr/Ca ratio of seawater was high. The evidence for changing chemistry of seawater also has implications for the application of the Sr/Ca and Mg/Ca paleothermometers, in particular for pre-Quaternary samples, and for the assessment of diagenetic alteration of fossil skeletal carbonates by using Sr/Ca ratios.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 30
Serial Issue: 12
Title: Phanerozoic record of plate tectonic control of seawater chemistry and carbonate sedimentation
Affiliation: Ruhr University, Institute of Geology, Mineralogy and Geophysics, Bochum, Federal Republic of Germany
Pages: 1123-1126
Published: 200212
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 42
Accession Number: 2002-079386
Categories: StratigraphyHydrochemistry
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table
Secondary Affiliation: University of Ottawa, CAN, Canada
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 200224
Close Modal

or Create an Account

Close Modal
Close Modal