Stratigraphic development of Ship Shoal, northern Gulf of Mexico

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6463589

Penland, S; Suter, J R; Moslow, T F

Ship Shoal is the easternmost member of a Holocene inner-shelf shoal group located 25 km offshore of the Mississippi River delta plain in south-central Louisiana. Ship Shoal is a shore-parallel sand body 50 km long and 8-12 km wide, lying in 10 m of water with a relief above the surrounding shelf of 3 m to 7 m east to west along its crest axis. A comparison of hydrographic surveys indicate that the shoal has migrated 2 km landward since 1850. High resolution seismic profiles document Ship Shoal is an isolated sand body which punches out seaward on the erosional inner shelf and terminates landward on a depositional surface. Vibracores document Ship Shoal is 305 m thick sand body composed of shoal crest, lower shoal, back shoal, and lagoonal deposits lying disconformably over regressive deposits of the Maringouin delta complex, transgressed 6000 years B.P. The stratigraphy of Ship Shoal indicate it originated during the transgression of a Holocene barrier shoreline associated with the Maringouin delta complex. The presence of reworked clasts of beach rock Crassostrea sp. shell, and Rangia sp. shell within the sand body and overlying in-situ lagoonal deposits, document the former existence of a barrier shoreline. The transgressive shoal sequence shows that Ship Shoal has migrated to its present position from a more seaward location and the shoal and body contained no in-situ barrier shoreline deposits. The development of Ship Shoal illustrates a process whereby transgressive barrier shorelines are transformed into reworked barrier sand bodies lying on the inner shelf during relative sea level rise.

• Research Organization: Louisiana Geological Survey, Baton Rouge (USA)
• OSTI ID: 6463589
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
CENOZOIC ERA
CONTINENTAL MARGIN
CONTINENTAL SHELF
DEPOSITION
FEDERAL REGION VI
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGY
GEOPHYSICAL SURVEYS
GULF COAST
LOUISIANA
NORTH AMERICA
QUATERNARY PERIOD
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SEISMIC SURVEYS
STRATIGRAPHY
SURVEYS
USA