Barton Springs - Geology

Geology

Barton Springs is the main discharge point for the Barton Springs segment of the Edwards Aquifer of Texas, a well known karst aquifer. Geologically, the aquifer is composed of limestone from the Cretaceous period, about 100 million years old. Fractures, fissures, conduits, and caves have developed in this limestone. Both physical forces, such as faulting, and chemical forces, such as dissolution of limestone by infiltrating water, have enlarged these voids. This results in a karst aquifer made up of limestone with large void spaces. Water then enters the aquifer and fills the voids.

All water discharging from Barton Springs originates as rainfall. Some of this rain falls directly onto the area of land where the aquifer limestone rock is exposed, which is known as the recharge zone. Other rainfall enters into creeks that cross the recharge zone, and infiltrates the limestone bedrock. After water enters the aquifer, it flows along the gradients created by differences in hydraulic pressure into the area of lowest hydraulic pressure. This lowest point of hydraulic pressure is Barton Springs.