Distribution and textural character of surficial sediments, Isles Dernieres to Ship Shoal region, Louisiana

Conference · Fri Sep 01 04:00:00 EDT 1989 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5112563

Williams, S J; Circe, R ^[1]; Penland, S ^[2]

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1. Geological Survey, Reston, VA (USA)
2. Geological Survey, Baton Rouge, LA (USA)

Since 1986, the US Geological Survey and the Louisiana Geological Survey have undertaken field studies of the physical processes responsible for the widespread and extremely rapid coastal erosion of Louisiana's barriers along the Mississippi River delta plain coast. The study area encompasses the coastal and inner shelf region from Raccoon Point to Sandy Point and includes a database of 12-m long vibracores, surface grab samples, sidescan sonar, high resolution seismic reflection profiles, and precision hydrographic profiles. This paper presents results in the coastal-shelf sector that includes the Isles Dernieres barrier island chain seaward almost 30 km to Ship Shoal. The surface and near-surface sediments of the region reflect fluvial and nearshore marine origin with pervasive evidence of winnowing and reworking by marine processes associated with frequent tropical storms and the passage of winter cold fronts. Beach sediments are remarkably uniform in grain size (fine quartz sand), except for the often abundant presence of carbonate shell debris, and are generally well to very well sorted. The shoreface and inner shelf are mantled with muddy sands and sandy muds, whereas, Ship Shoal is almost wholly fine quartz sand, similar in many sedimentologic respects to the Isles Dernieres. The results are consistent with the model of coastal evolution, presented in 1988, in which Ship Shoal is the prototypical example of a drowned coastal barrier undergoing submarine reworking and landward migration in pace with the rapid rates of sea level rise and subsidence.

• OSTI ID: 5112563
• Report Number(s): CONF-8910221--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 73:9
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
DRILLING
EROSION
FEDERAL REGION VI
GEOLOGY
HYDROLOGY
ISLANDS
LEVELS
LOUISIANA
NATIONAL ORGANIZATIONS
NORTH AMERICA
RESEARCH PROGRAMS
SEA LEVEL
SEDIMENTS
STRATIGRAPHY
US DOI
US ORGANIZATIONS
USA
WELL DRILLING