Facies in a shelf-edge delta - An example from the subsurface of the Gulf of Mexico, middle Pliocene, Mississippi Canyon, Block 109

Journal Article · Wed Apr 01 04:00:00 EST 1992 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7068254

Mayall, M J; Yeilding, C A; Oldroyd, J D; Pulham, A J ^[1]; Sakurai, S ^[2]

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1. BP Exploration, Houston, TX (United States)
2. ARCO Research Lab., Plano, TX (United States)

Two vertically stacked shelf-edge delta systems, in the middle Pliocene of Mississippi Canyon Block 109, have been described using a three-dimensional seismic survey, 400 ft (122 m) of conventional core, and electric logs. Possible characteristic facies associations and features of these shelf-edge deltas include extensive upper delta-slope deformation; locally ponded, slump-induced turbidites in the upper slope; a complex association of gravity and tractional deposits; relatively thin, preserved mouth-bar deposits; and the absence of delta-plain facies. Six facies have been identified in cores: (1) structureless sands interpreted as high density turbidites; (2) laminated sands; (3) thinly interbedded ripple-laminated sands; (4) contorted, muddy, fine sands and silts interpreted as mud flows and slumps; (5) laminated silts and muds interpreted as low-energy wave deposits or possibly d-division turbidites; and (6) muds interpreted as quiet water deposits. The upper delta is represented on seismic data as a series of prograding clinoforms approximately 400 ft (122 m) thick. Electric logs indicate these clinoforms are composed of a lower mud-dominated interval, an upper delta slope dominated by slumps with areally restricted turbidite sands, and coarsening- and cleaning-upward mouth-bar deposits composed of ripple-laminated and parallel-laminated sands interbedded with muds and silts. The lower delta contains similar vertical sequences, but also contains a distinct log and seismic facies that may be either a major shelf-edge failure or a later channel feature incised across the entire delta. Apart from this possible channel, neither delta shows evidence of emergent delta-plain facies.

• OSTI ID: 7068254
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 76:4; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

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03 NATURAL GAS
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ATLANTIC OCEAN
CARIBBEAN SEA
CENOZOIC ERA
COASTAL REGIONS
CONTINENTAL MARGIN
DEPOSITION
ELECTRIC LOGGING
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGY
GEOPHYSICAL SURVEYS
GULF OF MEXICO
LITHOLOGY
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
PLIOCENE EPOCH
RESERVOIR ROCK
RESOURCES
RIVER DELTAS
SEAS
SEDIMENTS
SEISMIC SURVEYS
STRATIGRAPHY
SURFACE WATERS
SURVEYS
TERTIARY PERIOD
WELL LOGGING