The Devil’s Graveyard & the strawberry Tuff

Some incredible geologic features of Trans-Pecos Texas make themselves evident in the volcaniclastic (sedimentary rocks composed of volcanic materials) rocks of the Devil’s Graveyard Formation, a layer of volcanic ash that was originally ejected from a series of volcanoes 42 million years ago and then carried away by rivers and streams and later deposited in lakes and riverbeds. 42 million years ago the dinosaurs had already been extinct for 24 million years and mammals (most of them completely unrecognizable to any of us today) had come to dominate the landscape. Many of these mammals have been preserved in this layer of volcaniclastic rocks and sediments.

To make this exposure even cooler, these hoodoos and gullies are topped by a younger and much harder layer of basalt which is protects the softer tuff below as the basalt is more resistant to erosion and weathering. The brick-red layer in the center is known as the strawberry tuff.