Exposure and flooding of carbonate platforms recorded in carbonate ooze and calciturbidites

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6602304

Schlager, W; Reymer, J; Ten Kate, W G.H.Z.; Sprenger, A ^[1]

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1. Free Univ., Amsterdam (Netherlands)

The tops of carbonate platforms are sensitive yet imperfect gauges of sea level because of their numerous lowstand unconformities. Deep-water sediments on the platform flanks can be used to complement the bank-top sections. Periplatform sediments accumulate continuously and combine information on plankton stratigraphy and oceanography in their pelagic fraction with information on exposure and flooding of the banks in the neritic fraction. Neritic input is governed by the principle of highstand shedding. During highstands of sea level, sedimentation rates are high and turbidites abundant bank-derived aragonite dominates in the perennial sediments and grains from the platform interior dominate in the turbidites. During lowstands, rates are low and turbidites rare; plankton dominates in the perennial sediment and skeletal grains from the bank margin in the turbidites. In this way, the Bahamas and the Maldives preserved a detailed record of Quaternary glacio-eustasy. The sea level signal in turbidites is especially useful because it is not erased by diagenesis. Triassic turbidites from the Alps display rhythmic variations in the ratio of biota from the bank margin and the bank interior. These variations fall in the same frequency range as the exposure cycles of the platform. Periplatform turbidites also record unique events, such as the transformation of the Bahama Banks from reef-rimmed atolls to flat-topped platforms in the Pliocene or the drowning of platforms on the Moroccan continental margin in the Early Cretaceous.

• OSTI ID: 6602304
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ALKALINE EARTH METAL COMPOUNDS
BAHAMA ISLANDS
CALCITE
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATE ROCKS
CARBONATES
CONTINENTAL MARGIN
CRETACEOUS PERIOD
DEVELOPING COUNTRIES
DIAGENESIS
DOLOMITE
GEOLOGIC AGES
GEOLOGIC HISTORY
ISLANDS
LEVELS
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MESOZOIC ERA
MINERALS
OXYGEN COMPOUNDS
ROCKS
SEA LEVEL
SEDIMENTARY ROCKS
WEST INDIES