Date of Award

Spring 5-9-2016

Degree Type


Degree Name

Master of Science - Geology



First Advisor

Dr. Kevin Stafford

Second Advisor

Dr. Wesley Brown

Third Advisor

Dr. Matthew McBroom


Karst development in the Edwards Aquifer has been significantly studied in the San Antonio and Barton Spring Segments; however, karst development remains poorly studied in the Northern Segment. Detailed characterization of the Northern Segment is vital for future water conservation because of increasing urban sprawl along the Interstate 35 corridor. The Northern Segment of the Edwards Aquifer consists of Lower Cretaceous strata of the Comanche Peak, Edwards, and Georgetown formations. The stratigraphy is dominated by Edwards Limestone as it is the only formation that crops out in the study area.

Karst, stratigraphic, GIS, and geochemical studies were conducted to evaluate development of karst and hydrogeology in the Salado Creek Watershed. GIS analyses included interpretations of digital elevation models derived from LiDAR data of the study area. Karst features found in the study area were analyzed and mapped as an assessment of the speleogenesis of specific features. Stratigraphic analyses found there are eight facies total on Critchfield Ranch ranging from low-energy depositional environments with the mudstones and wackestones to high-energy depositional environments with the packstones and grainstones. One facies found has a high vuggy porosity that limits cave development in the area, but promotes development of significant high permeability horizons. Geochemistry data suggested that there is a longer residence time of groundwater between the springs based on the differences in their chemistries. Of the three caves found on Critchfield Ranch, it was determined that they are all epigene caves with vadose and phreatic morphologies.




First and foremost I would like to thank the Critchfields for allowing me to do field work and research on their ranch. Specifically I would like to recognize Grant, Steve, and their parents Chester and Betty Critchfield. They all made sure we had anything and everything we needed and were very welcoming and supportive of the research. They are also some of the nicest people I have ever met and I am so glad I got the opportunity to conduct research on their property.

I would like to acknowledge my parents John and Libby Landers as well as my best friends who have supported and motivated me throughout the whole graduate school process. I would also like to thank Jessica Shields, Derek Sullivan, Ingrid Eckhoff, Asa Vermeulen, and Aubrey Jones for their help with field work and invaluable GIS knowledge and experience. My thesis committee for being there and helping with any questions I had.

Lastly I would like to thank Dr. Kevin Stafford. He has been the most help with this thesis. With so much knowledge and passion for his field of study, he has made the whole course of the thesis, from field work to defending, a fun, interesting, and unforgettable experience.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.



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