Marine & Environmental Sciences Faculty Articles

Biochemical and Ultrastructural Evidence for the Origin of Whitings: A Biologically Induced Calcium Carbonate Precipitation Mechanism

Document Type

Article

Publication Title

Geology

ISSN

0091-7613

Publication Date

5-1992

Abstract

We propose that Bahamian whitings, floating patches of lime mud, are in part the result of biological precipitation of calcium carbonate induced by picoplankton and cellular components. The cells may act as nucleation sites for crystallization from seawater supersaturated with CaCO3. Our model represents a new hypothesis concerning Bahamian whiting formation and is based on several lines of evidence. Biochemical data suggest that the macromolecules from carbonate suspended in Bahama Banks whitings are distinct from those found in the lime mud sediment producer Penicillus and from bottom sediment. Direct ultrastructural evidence indicates that mineralization occurs on the surfaces of picoplankton cells and degrading organic cellular components. The organic constituents include, but are not restricted to, whole and fragmented algal cells and composite structures ∼20-30 μm in diameter. The observed calcium carbonate crystals are distinct from skeletal debris. Because of the magnitude of the whiting phenomenon, calculations of carbonate sediment production budgets should include the potential contribution of calcium carbonate produced by epicefular precipitation. Knowledge of carbonate mud genesis is critical to interpretation of ancient occurrences of lime mud as well as to understanding ancient and global carbon cycles.

DOI

10.1130/0091-7613(1992)020<0464:BAUEFT>2.3.CO;2

Volume

20

Issue

5

First Page

464

Last Page

468

Comments

©1992 Geological Society of America

Additional Comments

NSF grant #s: OCE-8817343, OCE-8716168

This document is currently not available here.

Peer Reviewed

Find in your library

Share

COinS