Multiple outlier-reef trends off a carbonate platform: A new type of windward margin (south Florida)

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7262289

Lidz, B H; Shinn, E A ^[1]; Hine, A C ^[2]

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1. U.S. Geological Survey, St. Petersburg, FL (United States)
2. Univ. of South Florida, St. Petersburg (United States)

A new set of sidescan-sonar imagery and high-resolution seismic-reflection profiles provides enhanced definition of a system of multiple outlier-reef tracts off the lower Florida Keys. The reefs occur approximately 0.5 to 1.5 km seaward of the south Florida bank margin. The system comprises a massive, outer, main reef tract of high (28 m) unburied relief that parallels the margin, and at least two narrower, discontinuous reef tracts of lower relief between the main tract and the shallow platform-margin reefs. The outer tract is approximately 0.5 to 1 km wide and extends a distance of about 57 km. A single pass divides the outer tract into two main reefs. This outlier-reef system developed in response to sea-level fluctuations and apparently formed on antecedent, low-gradient to flat offbank surfaces, which are interpreted to be Pleistocene beaches that formed terrace-like features now in 30 to 40 m of water. Radiocarbon dates of a coral core from the outer tract confirm a pre-Holocene age. The multiple outlier-reef system represents a new type of windward margin that presents a significant, unique mechanism for progradation of carbonate platforms during periods of sea-level fluctuation. Infilling of the backreef basins would create new, submerged, terraced headlands and would extend or 'step' the platform seaward for hundreds of meters. Subsequent outlier-reef development would be dependent upon sea-level fluctuations and would result in laterally accumulating sequences. Implications are that similar subsurface outlier-reef systems may exist and that these systems could become clearly defined hydrocarbon reservoirs.

• OSTI ID: 7262289
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200 -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
ANIMALS
CNIDARIA
COELENTERATA
CORALS
DEVELOPED COUNTRIES
FLORIDA
GEOLOGIC DEPOSITS
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOLOGY
INVERTEBRATES
ISOTOPE DATING
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
ORIGIN
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
REEFS
RESERVOIR ROCK
RESOURCES
STRATIGRAPHY
USA