Geology of Nacogdoches, Texas : GEOGULF 2025

Nacogdoches and East Texas are geologically interesting places to live and work. This field trip will visit the locations indicated on the maps below (Figures 1 and 2). Our location is on the Sabine Uplift and is east of the East Texas Salt Dome Basin (Figure 3 and 4). The first producing oil well in Texas was drilled near Woden by Taliaferro Barret in 1866 at a depth of 106 feet, producing about 10 barrels a day from the Sparta Sand (Figures 5 and 6). Stratigraphic units that we will see are: Sparta Sand, Weches Formation, Queen City Sand, Reklaw Formation and Carrizo Sand (Figure 4). The Weches Formation consists of claystone that contain fossils, pellets, and outcrops in valleys and low areas in Nacogdoches. The Sparta Sand tops most hills in Nacogdoches and does not contain fossils. Queen City Sand and Reklaw Formation are not well exposed in Nacogdoches. Outcrops of the Carrizo Sand contain excellent cross bedding and is exposed on the tops the hills near Mt. Enterprise. The Mt. Enterprise fault system in our area has recently had a number of earthquakes with magnitudes as high as 4.8 on the Richter Scale