High-resolution seismic stratigraphic analysis of the Late Quaternary upper slope and shelf edge: Main Pass-Viosca Knoll area, Gulf of Mexico

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

OSTI ID:7013189

McMillen, K J ^[1]; Winn, Jr, R D ^[2]; Damuth, J E ^[3]; Weimer, P ^[4]

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1. Marathon Oil Co., Houston, TX (United States)
2. Marathon Oil Co., Littleton, CO (United States)
3. Mobile Oil Co., Dallas, TX (United States)
4. Univ. of Colorado, Boulder (United States)

High-resolution (800 Hz) sparker data from the Main Pass-Viosca Knoll area, offshore Louisiana, show shelf-edge deltas with oblique progradational clinoforms, parallel, and channel-fill reflections in the near-surface, latest Quaternary section of the upper slope. Sequence boundaries are indicated by onlap of slope facies onto older outershelf deltas and shelf margins, erosional truncation, and minor channel erosion on the top of progradational units and on the slope. The authors tentatively identify these sequence boundaries as Type I. Each depositional sequence consists of two seismic units: (1) a lower unit consisting of parallel, seaward-dipping reflections; (2) an upper unit consisting of parallel reflections and progradational clinoforms that converge or downlap downslope on top of the lower parallel unit. Precise correlation to absolute time and sea level awaits analysis and integration of shallow cores taken in the area by an industry consortium. Facies and isochron mapping of each sequence indicates an overall back-stepping of the shelf-edge deltas and shelf margins during the latest Quaternary. The Quaternary shelf edges are an area of isochron thicks and thins resulting from erosion and redeposition. Major channels commonly cross salt diapirs and may occupy the same site during successive lowstands. Comparison with multichannel seismic profiles shows that each shelf-edge delta seen on the high resolution profiles is represented by a single reflection on multichannel data. Steep clinoforms, downlap surfaces, and individual sequences are not seen on the multichannel data.

• OSTI ID: 7013189
• 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

58 GEOSCIENCES
580000* -- Geosciences
ATLANTIC OCEAN
CARIBBEAN SEA
CENOZOIC ERA
CONTINENTAL MARGIN
CONTINENTAL SLOPE
DEVELOPED COUNTRIES
FEDERAL REGION VI
GEOLOGIC AGES
GEOLOGY
GEOPHYSICAL SURVEYS
GULF OF MEXICO
LOUISIANA
NORTH AMERICA
OFFSHORE SITES
QUATERNARY PERIOD
SEAS
SEISMIC SURVEYS
STRATIGRAPHY
SURFACE WATERS
SURVEYS
USA