Would be interesting to see these tent rocks in New Mexico, next time I'm there...http://www.amusingplanet.com/2014/11/kasha-katuwe-tent-rocks.html
Kasha-Katuwe Tent Rocks is a unique group of rock formations located in the foothills of the Jemez Mountains, north-central New Mexico, U.S., between Albuquerque and Santa Fe, about 40 miles southwest of the latter. The area features large, tent-shaped rocks hugging the steep cliffs of Peralta Canyon, the product of powerful forces of vulcanism and erosion, which have built up and then torn down this landscape.
The cone-shaped tent rock formed out of pumice, ash, and tuff deposits over 1,000 feet thick that escapes from volcanic eruptions from Jemez volcanic field that occurred 6 to 7 million years ago. Over this, “pyroclastic flow” composed of rock fragments and searing hot gases blasted down slopes in an incandescent avalanche.
Over time, wind and water cut into these deposits, creating canyons and arroyos, scooping holes in the rock, and contouring the ends of small, inward ravines into smooth semi-circles. As a result, the tent rocks cones have cores composed of soft pumice and tuff beneath harder caprocks. Some tents have lost their hard, resistant caprocks and are disintegrating. While fairly uniform in shape, the tent rock formations vary in height from a few feet up to 90 feet.
