The Permian Period, the last geologic division of the Paleozoic Era, stretched from 270 to 225 million years ago. This Period is known primarily for two significant events: the merging of Earth's land masses into the mega-continent of Pangea and the greatest mass extinction in the history of our planet. The latter, which occured at the end of the Permian, eliminated 70% of terrestrial species and 95% of marine life, including the trilobites.
Permian rocks are exposed in many areas across North America but are concentrated in a swath that stretches from northeast Kansas to southeast New Mexico. Beginning at the north end, the Flint Hills, carved from Permian sedimentary rocks, rise north of Manhattan, Kansas, and run southward to the Oklahoma border. This scenic ridge and valley topography harbors our most extensive remnants of tallgrass prairie.
Permian redbeds color the landscape of south-central Kansas, expanding southward through all of central Oklahoma and into north-central Texas. Southwest of these beds is the Permian Basin, one of the thickest layers of Permian rock on Earth and known for its rich oil and gas deposits; this formation runs from Lubbock down to Odessa but is buried by younger sediments of the Cenozoic Era. The Permian strata reappear as the Guadelupe Mountains, east of El Paso, and the Glass Mountains, north of Marathon. The former are part of an uplifted Permian reef and culminate in Guadelupe Peak, 8749 feet, the highest point in Texas. The reef dips below younger sediments in southeast New Mexico, where its Permian limestone has been dissolved by groundwater to form the fabulous Carlsbad Caverns.