Multiple submarine-cemented grainstone sequences along leeward carbonate margins: examples from late Quaternary of Little and Great Bahama Banks

Conference · Fri Feb 01 04:00:00 EST 1985 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:5624502

Jude, W R; Hine, A C; Neumann, C

Coarse-grained, leeward-margin sand shoals, developed during the late Quaternary along the western edges of Little and Great Bahama Bank, have been deposited and preserved in response to regional sediment-transport process and local physicochemical conditions. These sand bodies are fundamental depositional sequences, chronostratigraphically bounded by subaerial exposure crusts, and thus are of major importance in determining rates of bank-margin growth and in understanding the dynamics of carbonate margin buildup. Surficial sediment is composed of coarse sand and granules dominated by composite-ooid grains. Submarine cementation is active and has led to the development of coarser grains are cemented with fibrous aragonite and surficially coated at the tidally active margin. The resultant composite-ooid sediment is more hydrodynamically stable and is rapidly cemented into hardgrounds characterized by a smooth upper surface. Lithification is gradational through a thickness of 50-100 m to an irregular lower boundary transitional with uncemented material. These hardgrounds are submarine discontinuity surfaces developed during inter-storm conditions of winnowing and bypass sedimentation along a depositional profile of equilibrium. Rock cores into the Pleistocene section have recovered sediments and submarine discontinuity surfaces identical to those in the Holocene. These are present in the two latest Pleistocene sequences representing the last major interglacial intervals. Both the Holocene and Pleistocene sequences have one or two cemented zones per meter in the upper section. The presence of these deposits throughout the preserved stratigraphic package indicates the persistence of characteristic leeward depositional processes during the late Quaternary and their importance in bank-margin growth.

• Research Organization: Sea Education Associates, Woods Hole, MA
• OSTI ID: 5624502
• Report Number(s): CONF-850322-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 69:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
BAHAMA ISLANDS
CARBONATE ROCKS
CENOZOIC ERA
DEPOSITION
DEVELOPING COUNTRIES
GEOLOGIC AGES
ISLANDS
QUATERNARY PERIOD
RESERVOIR ROCK
ROCKS
SEDIMENTARY ROCKS
WEST INDIES