had just finished an exercise at Gower Gulch at the north end of the Black Mountains and we walking back to the vehicles when a sliver of sky opened up. The sun blazed forth in all its glory.
And the rock...Death Valley has perhaps the greatest variety of rock types to be found in any national park. They range in age from 1.7 billion to practically yesterday. They include all of the types, plutonic, volcanic, sedimentary, and metamorphic. The rocks occur in nearly all the colors of the rainbow, sometimes in a single outcrop (google Death Valley's Artist Palette if you want to see what I mean). And in most parts of the park there is no vegetation or soil to obscure their complicated structures and relationships.
The rocks we were looking at were part of the Mio-Pliocene sediments and ash/lava flows of the Furnace Creek, Funeral, and Artist Drive formations. They accumulated in a fault basin not totally unlike the present-day Death Valley graben. There were ephemeral lakes, alluvial fans, floodplains, and volcanoes. The plains probably supported a rich fauna of camels, horses, mastodons, birds and predatory cats, who left their tracks in similar-aged rocks elsewhere in the park.
Addendum: Since we are talking the incredible fossil record of Death Valley, there is news this week of some horrible human beings who have stolen some of the precious fossil trackways I mentioned. I can only hope that the pictures of the probable thieves will lead to arrests and convictions. More information can be found here: http://vertpaleo.org/Society-News/SVP-Paleo-News/Paleontology-News/Fossils-Stolen-from-Death-Valley-National-Park.aspx