Description: South Texas is rich in many natural resources, much of it derived from its Cretaceous bedrock. During the Cretaceous Period (~145-65 million years ago), a seaway (known as the Western Interior Seaway) flooded the central part of Texas. Over this period of time sea level rose and fell depositing marine sediment representing shallow to deep marine environments. A group of formations called the Edwards Group includes limestones that are highly porous and permeable. These rocks make up the karst aquifer called the Edward Aquifer and is the source of water for much of South Texas. Two stops in this trip will be locations where the Edwards Aquifer discharge in artesian springs (Blue Hole and the Steven’s Homestead). More information on the Edwards Aquifer can be found at: http://www.edwardsaquifer.org/ The Blue Hole is one of a number of ephemeral springs known as the San Antonio Springs. They are part of the headwaters of the San Antonio River. The springs are located near the campus of the University of the Incarnate Word. More information can be found at: http://www.headwaterscoalition.org/ The Steven’s Homestead is located in the historic King William District of San Antonio. The house was built in 1876 and in 1912 an artesian well was drilled which fed one of the first natatoriums in San Antonio. More information can be found at: http://www.saconservation.org/EducationTours/HistoricalTours/tabid/130/ArticleID/59/ArtMID/560/Edward-Steves-Homestead.aspx The Eagle Ford Group was deposited after the marine limestones that make up the Edwards Group. High amount of organic carbon burial is the source of abundant oil and natural gas. Increased utilization of a technique called hydraulic fracturing (fracking) has spurred a boom in exploration and drilling in South Texas. Most of the drilling sites are located south of San Antonio and this is where we will visit a drilling site. More information on the Eagle Ford Group can be found at: http://eaglefordshale.com/geology/