Publication Date

2018-07-17

Availability

Embargoed

Embargo Period

2020-07-16

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Marine Geology and Geophysics (Marine)

Date of Defense

2018-06-18

First Committee Member

Peter K. Swart

Second Committee Member

Ali Pourmand

Third Committee Member

James Klaus

Fourth Committee Member

Chris Langdon

Fifth Committee Member

Nicola Allison

Abstract

The rise and fall of scleractinian coral dominated reefs throughout the Phanerozoic is strongly linked to the changes in the Earth’s climate and the chemistry of seawater (calcite vs. aragonite oceans). Changes in both the ocean’s saturation state and ion chemistry have had profound effects on the biomineralization process; calcite is precipitated in low Mg/Ca seawater, while aragonite is precipitated in high Mg/Ca seawater and the precipitation of these minerals is primarily controlled by the composition and saturation state of seawater. Corals do not precipitate their skeletons in equilibrium with seawater and vital effects (physiological processes that are responsible for variability in coral elemental ratios) may confound any paleoenvironmental signals potentially recorded. In order to determine what is recorded in biogenic carbonates, the effect of seawater chemistry on calcification and vital effects must be determined. In this dissertation, I present a series of experiments to manipulate the saturation state, Mg2+, Ca2+ and SO42- concentrations of seawater. This body of work has important implications for understanding the evolutionary and life history of scleractinian corals.

Keywords

Biomineralization; Calcite and Aragonite Seas; Paleoclimate Proxies; Distribution Coefficients; Vital Effects; Calcium

Available for download on Thursday, July 16, 2020

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