The Caverns Were Part of a Reef Millions of Years Ago • I am New Mexico

The Caverns Were Part of a Reef Millions of Years Ago

Capitan Reef

The Capitan Reef is made of countless tiny skeletons from millions of years ago – the ultimate in a team effort.
Photo by @spaghetti.western

About 80 million years ago tectonic compression along the western margin of North America caused the region encompassing west Texas and southern New Mexico to be slowly uplifted. A transition in tectonic events 20-30 million years ago initiated the formation of steep faults along the western side of the Delaware Basin. Movement on these faults over the last 20 million years caused a long-buried portion of the Capitan Reef to rise several thousand feet above its original position. This uplifted block was then exposed to wind and rain causing the softer overlying sediments to erode, uncovering the more resistant fossil reef and forming the modern Guadalupe Mountains. Today the reef towers above the desert floor as it once loomed over the floor of the Delaware Sea 260 to 265 million years ago. (Source: