Framework and Evolution of a Transgressed Delta Lobe: The St. Bernard Shoals, Gulf of Mexico

Four modern shoals on the Louisiana continental shelf are proposed to have formed through transgression, marine reworking, and submergence of Mississippi River deltaic lobes. However, one of these shoals, the St. Bernard Shoals, is dissimilar to the other shoals in morphology and stratigraphy. Understanding the processes that lead to these differences resulted in the development of a wholly new model for subaqueous shoal evolution. The results of this study suggest that the St. Bernard Shoals are transgressive remnants of a near shelf-edge delta lobe that was transgressed and truncated by marine processes after fluvial abandonment. Subsequent to truncation, the shoals formed through subaqueous excavation and reworking of coarse grained sediment contained within underlying distributary channels by hurricane related marine currents. As a result the shoals are bound at their base by a ravinement surface and lie directly upon progradational facies associated with previously unrecognized southern progradation of the La Loutre distributary network.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Earth and Environmental Sciences

Year

2009

Author dc:creator

• Rogers, Bryan E.

Contributors dc:contributor

• Kulp, Mark A.
• Miner, Michael
• Lavoie, Dawn

• shoal
• transgression
• deltaic evolution
• Mississippi River delta
• St. Bernard Shoals
• shelf currents
• transgressive history
• tropical cyclones
• secondary reworking

Repository record dc:identifier

https://scholarworks.uno.edu/td/968

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-1949