HR: 1330h
AN: H52A-1176 [PDF]
TI: Influence of the Atchafalaya River on Stratigraphic Evolution of the Chenier Plain Inner Shelf,
Northern Gulf of Mexico
AU: * Draut, A E
EM: adraut@alum.mit.edu
AF: US Geological Survey - UC Santa Cruz, USGS Pacific Sciences Center, Santa Cruz, CA 95060 United States
AU: Kineke, G C
EM: kinekeg@bc.edu
AF: Dept. of Geology and Geophysics, Boston College, Chestnut Hill, MA 02467
AU: Velasco, D W
EM: 1david@velasco.com
AF: Sontek / YSI Inc., 6837 Nancy Ridge Dr., San Diego, CA 92121 United States
AU: Allison, M A
EM: malliso@tulane.edu
AF: Department of Earth & Environmental Sciences, Tulane University, New Orleans, LA 70118 United States
AU: Prime, R J
EM: prime861@hotmail.com
AF: Dept. of Geology and Geophysics, Boston College, Chestnut Hill, MA 02467
AB:
This study provides new constraints on the influence of the Atchafalaya River, a major distributary of the Mississippi River,
on stratigraphic evolution of the Northern Gulf of Mexico inner continental shelf. Sedimentary, geochemical, and shallow
acoustic data have been used to identify the western limit of the distal Atchafalaya subaqueous delta, and to estimate the
proportion of Atchafalaya River sediment that accumulates seaward of Louisiana's chenier plain coast. The results demonstrate
a link between facies distribution on the inner shelf and geomorphic variation on the chenier plain. A zone of coastal
mudflat progradation corresponds to the location of Atchafalaya sediment accumulation on the inner shelf. West (downdrift) of
the subaqueous delta, relict sediment is exposed that was originally deposited between ~1200 and 600 years BP during
activity of the Lafourche lobe of the Mississippi Delta complex. Mass balance calculations indicate that the eastern chenier
plain inner shelf and coastal zone form a sink for 7 +/- 2% of the Atchafalaya River sediment load.
DE: 1815 Erosion and sedimentation
DE: 4219 Continental shelf processes
DE: 4546 Nearshore processes
DE: 4558 Sediment transport
SC: Hydrology [H]
MN: 2003 Fall Meeting