From the Edward’s Aquifer website: The Balcones Escarpment is the topographic expression of the Balcones Fault…. This zone is where the Gulf Coastal Plains transition into the Texas Hill Country. Vastly different land uses on either side of the Escarpment are evident in satellite imagery.
Below the Escarpment is the blackland prairie of the Gulf Coast where agriculture and urban uses are dominant, while above the Escarpment lies the Texas Hill Country where ranching and grazing are common. Displacement of the Balcones is about 1200 feet. However, one thing that really bothers geologists around here is they don’t know whether this displacement occurred all at once, such as during a powerful earthquake, or over a long period of time.
Property on the Balcones Escarpment, especially where it runs through northern San Antonio and western Austin, is highly valued for its rugged Hill Country beauty and lovely views of the city lights.
From the Texas State Historical Association website: The Balcones Escarpment is a geologic fault zone several miles wide consisting of several faultings. It extends in a curved line across Texas from Del Rio to the Red River and is visible eastward from Del Rio, where it is about 1,000 feet high, and northeastward from San Antonio to Austin, where it is about 300 feet high.
The escarpment, which appears from the plains as a range of wooded hills, separates the Edwards Plateau in the west from the Coastal Plains. The Balcones zone was formed under conditions of strain during the Tertiary era, when a downwarping occurred near the Gulf Coast with a moderate uplift inland. Water-bearing formations passing beneath the plateau to the plains are broken across by the Balcones fault group, and much water is forced to the surface by artesian pressure.
Barton Springs, San Marcos Springs, and Comal Springs are examples of the resulting artesian wells or springs.