Sedimentology and sequence stratigraphy of upper Pleistocene carbonates of southeastern Barbardos, West Indies

Journal Article · Thu Nov 01 04:00:00 EST 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5690253

Humphrey, J D; Kimbell, T N ^[1]

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1. Univ. of Texas, Richardson (USA)

Upper Pleistocene reef-associated carbonates of southeastern Barbados have been studied in outcrop and core. Reef terraces, formed during glacio-eustatic sea level highstands and subsequently uplifted, are characterized by thick and areally extensive sequences of allochthonous and autochthonous fore-reef calcarenites. Depositional textures are primarily packstones, and grainstones, wackestones, and coral floatstones are volumetrically less significant. Sediments are coarse- to fine-grained reef-derived allochems and micrite, and autochthonous benthic foraminifera and coralline red algae. Rates of sediment accumulation of fore-reef calcarenites range from about 1 to 4 m/1,000 yr. Although of relatively small scale, the carbonate terraces of southeastern Barbados provide excellent analogs for sequence stratigraphic concepts in carbonate settings. The terraces are primarily highstand systems tract deposits separated by type 1 unconformities. These highstand deposits are characterized by reef development and the progradation of fore-reef calcarenites. Extensive fore-reef deposits resulted from mechanical erosion of the reef framework on this high-energy, windward coastline. Type 1 unconformities are characterized by thin caliche layers developed during lowstand subaerial exposure. Thin basal transgressive systems tract deposits are characterized by incorporation of extraformational clasts derived from the underlying sequence during sea level rise. Slope-front erosion, vertical shift in the position of freshwater lens, and shift in the position of coastal onlap are all consequences of the interplay between eustasy and tectonics. These effects and the development of facies geometries on Barbados are primarily controlled by the glacio-eustatic component, inasmuch as rates of eustatic changes of sea level are at least two orders of magnitude greater than the maximum average rates of tectonic uplift. 12 figs.

• OSTI ID: 5690253
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Vol. 74:11; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
ALGAE
ANIMALS
BARBADOS
CARBONATE ROCKS
CENOZOIC ERA
DEPOSITION
EROSION
EXPLORATION
FORAMINIFERA
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOLOGY
INVERTEBRATES
ISLANDS
LESSER ANTILLES
LEVELS
MICROORGANISMS
PLANTS
PLEISTOCENE EPOCH
PROTOZOA
QUATERNARY PERIOD
REEFS
ROCKS
SARCODINA
SEA LEVEL
SEDIMENTARY ROCKS
SEDIMENTS
STRATIGRAPHY
TECTONICS
WEST INDIES