27 April 2015
Throughout the Texas Hill Country you find examples vastly different from those found in Maine. For miles you will see cuts through ridges where thin parallel layers of sedimentary rock appear to be continuous from one section to another. These were formed when this region was under water and solids from all over the world found their way here and settled over long periods of time.
The age of the Earth is demonstrated with the many fossils that are found in these layers easily viewed along West Texas highways. For example, the ones taken along I10, just East of Sonora show long periods of quiet in the Earth’s history, seen here as compared to the upheaval seen in the Maine geology.
The abundance of oil in Texas is due to upheaval during the Pennsylvanian period (300 million years ago). In the collision of the plates forming the supercontinent Pangaea, an abundance of organic rich mudstones were pressed under the limestone, forming the oil over a long period of time. Additional formations occurred during the Permian-Devonian periods (245 million years ago).
Activity at the Northeastern corner of the Texas Oklahoma border is discussed in the Oklahoma Geology page.