These sands rest upon impermeable Miocene sediments that overlie limestone, which was dissolved by groundwater and collapsed to form Tulane Lake.

It is oblong in shape, has a surface area of 88 ares (95,000 sq ft) and has a maximum depth of 70 feet (21 m).

The organic-rich sediments, which underlie the bottom of Lake Tulane, provide one of the few records of ancient climates within eastern North America that extends beyond the late glacial period (~ 15,000 cal years BP).

Cores from the bottom of Lake Tulane have yielded a record of paleoclimates and paleovegetation, which date back to before 60,000 BP.

The Pre-Holocene pollen record shows alternating periods of Pinus (pine)-dominated and Quercus-Ambrosia (oak-ragweed)-dominated vegetation.