Origin of fine-grained Holocene shallow marine carbonate sediment on the Florida-Bahama Platform

Conference · Tue May 01 00:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6599896

Steinen, R ^[1]; Tennet, P ^[2]

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1. Univ. of Connecticut, Storrs (USA)
2. British Petroleum, Houston, TX (USA)

Fine-grained sediments present in Florida Bay, the inner reef tract of Florida, and the Great Bahama Bank are formed by three processes. The sediments differ primarily in the amount of 4-{mu}m-long aragonite needles that comprise the sediment, but also in the amount of aragonite. Florida Bay muds are composed primarily of equant 1 {mu}m grains; less than 20% are needles. The fine-grained fraction from the inner reef tract of Florida contains more aragonite needles than Florida Bay muds. Some samples contain nearly 90% needles, whereas samples, from adjacent localities contain only 50%. Sediment from both areas is deposited and mixed by bioturbation on the deltas at tidal passes through the Florida Keys. The amount of needle sediment diminishes rapidly away from the tidal passes in Florida Bay. The fine-grained fraction on the Great Bahama Bank is dominated by 4-{mu}m-long needles of aragonite but may contain fragments and whole tests of foraminifers. In general, the more abundant the aragonite-needle content is in any of the sediment, the greater the aragonite content of that sediment. The three main processes responsible for mud production on the Florida-Bahama Platform are (1) disintegration of skeletal encrustations, mainly red algae and spirobid worm tubules, on Thalassia grass blades; (2) postmortem disaggregation of aragonite needles from green algae; and (3) direct precipitation of aragonite and Mg-calcite from supersaturated marine waters. Where sufficient nutrients exist in the water column, such as in Florida Bay, mud production is dominated by the epibionts on the Thalassia grass community. Less nutrients in the water column of the inner reef tract results in fewer encrustations.

• OSTI ID: 6599896
• Report Number(s): CONF-900605-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:5; Conference: Annual convention and exposition of the American Association of Petroleum Geologists, San Francisco, CA (USA), 3-6 Jun 1990; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
BAHAMA ISLANDS
CARBONATE ROCKS
DEPOSITION
FLORIDA
ALGAE
CALCITE
DOLOMITE
QUATERNARY PERIOD
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
CENOZOIC ERA
DEVELOPING COUNTRIES
FEDERAL REGION IV
GEOLOGIC AGES
ISLANDS
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERALS
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OXYGEN COMPOUNDS
PLANTS
ROCKS
SEDIMENTARY ROCKS
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