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Desert Diary


Most caves form within such sediments as limestone and gypsum. In volcanic regions throughout the world, including the Southwest, caves of a different sort occur. Lava, like other liquids, flows downhill. Under some circumstances, the upper surfaces of a flow cool and harden, while beneath this crust still-liquid lava continues to flow. When the lava supply is cut off, the melted rock already in the pipeline may continue to run downhill, leaving behind an empty tunnel within the lava itself. Through the ages, weak places in the roof may give way, allowing access to animals who enjoy dark, cool spaces.

Another volcanic source of cavities within rocks comes from gas entrapped within the magma venting to the surface while the lava surrounding the hot gas solidifies enough to hold its shape. Such a passage way is a fumarole, and Aden Fumarole in southern New Mexico forms a nearly vertical vent some hundred feet deep. Its fame lies in its victim—a ground sloth recovered some 11,000 years after falling in, complete with patches of fur and hide.
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Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.


Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.