Black Mesa – November 4, 2020
It’s Science Wednesday! Yesterday we did a sunset trail run on Black Mesa, Oklahoma’s highest point at 4,973 ft. Black Mesa is actually a 3-5 million year old basaltic lava flow, originating from a vent that erupted in a volcanic field spanning northeastern New Mexico and southeastern Colorado. The flow is 600 feet thick and 55 miles long.
So, what makes the mesa (higher elevation, flat-topped) formations in this region? The lava originally erupted and then flowed through pre-existing stream channels made up of sedimentary rock. Over time, a lot of surrounding sedimentary rock eroded away, leaving behind a higher resistant lava flow “cap” but still with preserved layers of sediments underneath. In 1935, tons (literally) of dinosaur bones were found in this underlying remaining sedimentary rock, such as stegosaurus, as well as preserved footprints of the allosaurus!
photo: U. Horodyskyj