On Little Stave Creek, a tributary to Tombigbee River, Alabama, within a distance of less than 3 miles, an early Tertiary section of clays, sands, marls, and limestones totaling 400 feet is exposed. The oldest units are referred to the middle Eocene Tallahatta formation, the youngest to the Mint Spring marl member of the Oligocene Marianna limestone. The faunas are dominantly molluscan, including oyster reefs and, at some levels, a prolific growth of corals.
It is believed that the faunas lived on or in mud or sands under continental-shelf or estuarine waters that were as warm as, or warmer than, those of the northern Gulf of Mexico today. Average depths were 40 fathoms or less.
Most of the assemblages are somewhat mixed and contain shells that were brought in by bottom currents. There is no strong evidence of reworking except at important contacts such as that between the Lisbon formation and the Gosport sand.