Science is Fun Fridays

 My Shots - Red Rock Canyon

500 million years ago, this area was at the bottom of an ocean basin.  The gray mountains are made up of Paleozoic limestone and dolomite.

Then there's the Aztec sandstone, colored red from iron oxide or hematite.

The spots are iron concretions, where subsurface water has precipitated iron oxide.

Dinosaur tracks have been found in the sandstone, as well as petroglyphs.  There is a nearby spring that helped sustain Southern Paiute tribes living in the canyon.

In the mountains you can see the results of the Keystone Thrust Fault.  When the oceanic plate began subducting the western edge of the North American plate, compressional forces caused the older limestone to be thrust up over the younger sandstone, so the limestone served as a cap which slowed erosion of the sandstone.