--> ABSTRACT: Delta Deposition Influenced by Diapiric Uplifts, by Jack L. Kindinger; #91030 (2010)

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Delta Deposition Influenced by Diapiric Uplifts

Jack L. Kindinger

The continental shelf in the northern Gulf of Mexico is overlain by many superimposed deltas. One late Wisconsinan delta, here informally named the lagniappe, is located east of the Mississippi River birdfoot delta and extends from mid-shelf to the continental slope. The lagniappe delta is adjacent to, but not genetically associated with, the Mississippi River delta complex.

The lagniappe delta is a shelf-margin delta formed in part by stream erosion of the exposed inner and outer shelf during the late Wisconsinan lowstand. On the basis of its overall pattern and direction of accretion, the delta's fluvial source was most probably the ancient Pearl or Mobile River farther east. The progradational deposits, as seen in the high-resolution seismic reflection profile, are characterized by foreset and bottomset bedding.

Areal distribution and sediment thickness were partially controlled by two diapirs active before and during deltaic sedimentation. The diapirs were a barrier to seaward progradation. As the delta prograded seaward, sediment ponded in an area between and shoreward of both uplifted diapirs. The basic geometry of the lagniappe delta was effectively changed during deposition by the presence of these diapirs.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.