Abstract: Claiborne-Jackson Contact (Eocene) in Alabama and Mississippi

Ernest A. Mancini, Berry H. Tew

The Claiborne-Jackson Group contact corresponds to a type 1 unconformity within the Bartonian Stage in southwestern Alabama and southeastern Mississippi. Transgressive glauconitic sands of the Gosport Sand of the Claiborne Group are part of the TAGC 4.1 depositional sequence and disconformably overlie progradational, highstand regressive lignitic clays of the Lisbon Formation of the Claiborne Group. These Lisbon clays are part of the TAGC 3.4 depositional sequence in southwestern Alabama. The Lisbon-Gosport contact corresponds to a type 1 unconformity. The Gosport glauconitic sands are highly burrowed and contain a basal lag of shark teeth and quartz pebbles. Transgressive glauconitic sands and marls of the Moodys Branch Formation of the Jackson Group are part of the TAGC 4.2 depositi nal sequence and overlie progradational, highstand regressive lignitic clays and sands of the Gosport. The Gosport-Moodys Branch contact corresponds to a type l unconformity. In southeastern Mississippi, where the TAGC 4.1 depositional sequence has not been recognized, transgressive glauconitic sands and marls of the Moodys Branch Formation disconformably overlie progradational, highstand regressive lignitic clays and sands of the Cockfield Formation of the Claiborne Group. The Cockfield-Moodys Branch contact corresponds to a type 1 unconformity. The uppermost beds of the Lisbon Formation, the Gosport Sand, and the Moodys Branch Formation have been assigned to the Bartonian planktonic foraminiferal Truncorotaloides rohri interval zone.

AAPG Search and Discovery Article #90983©1994 GCAGS and Gulf Coast SEPM 44th Annual Meeting, Austin, Texas, October 6-7, 1994