BALCONES ESCARPMENT. The Balcones Escarpment is a geologic fault zone several miles wide consisting of several faultings, most of which both dip and are downthrown to the east. 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. It was observed by zoologist G. W. Marnoch and was described by Robert Thomas Hill in 1890. 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 Springsqqv are examples of the resulting artesian wells or springs.

Patrick Abbott and C. M. Woodruff, eds., The Balcones Escarpment: Geology, Hydrology, Ecology (San Antonio: Geological Society of America, 1986). Edward Collins and Stephen Lauback, Faults and Fractures in the Balcones Fault Zone (Austin: Austin Geological Society, 1990). Robert T. Hill, "The Geologic Evolution of the Non-Mountainous Topography of the Texas Region: An Introduction to the Study of the Great Plains," American Geologist 10 (August 1892). E. H. Sellards, W. S. Adkins, and F. B. Plummer, The Geology of Texas (University of Texas Bulletin 3232, 1932).

Image Use Disclaimer

All copyrighted materials included within the Handbook of Texas Online are in accordance with Title 17 U.S.C. Section 107 related to Copyright and “Fair Use” for Non-Profit educational institutions, which permits the Texas State Historical Association (TSHA), to utilize copyrighted materials to further scholarship, education, and inform the public. The TSHA makes every effort to conform to the principles of fair use and to comply with copyright law.

For more information go to:

If you wish to use copyrighted material from this site for purposes of your own that go beyond fair use, you must obtain permission from the copyright owner.


The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this article.

Handbook of Texas Online, "BALCONES ESCARPMENT," accessed July 17, 2019,

Uploaded on June 12, 2010. Published by the Texas State Historical Association.

Get this week's most popular Handbook of Texas articles delivered straight to your inbox