Thursday, March 13, 2014

Out of the Valley of Death: Mountains and Mountains of Animals

So many colors in a desert environment! It was the second morning of our trip into the Valley of Death, or Death Valley National Park as others call it. On the previous day we had made our way across the southern end of the Sierra Nevada after searching for shark tooth fossils in the dusty hills near Bakersfield. We then crossed the Garlock fault at Red Rock Canyon State Park and drove north into the Owens Valley and looked at the dry water course at Fossil Falls. Late in the day we had forced passage over two mountain ranges, the Darwin Plateau at the south end of Inyo Mountains, and the Panamint Mountains. Of course, passing over mountain ranges in the modern day is a great deal less difficult than it used to be.
We set up camp in the dark, and so had no idea the scene that would greet us in the morning light. It was glorious. There was movement in the camp as the students started waking up and looking around. It was going to be an interesting day.

There was a storm brewing out in the Pacific Ocean, and I was sure we were going to catch a corner of it, but storms come to die in Death Valley just as surely as the dreams of avarice in the eyes of miners wither in the face of the desert heat. All we could see of the weather disturbance were the high clouds drifting above.
Few of the original settlers who were trapped in Death Valley and gave it the name actually died. On the other hand, the mountains that surround the valley are full of death, in a way. For several hundred million years the region that is today Death Valley was a passive continental margin on the edge of the (much smaller) North American continent. Rivers carried some sediment into deltas that connected to the shelf, but mostly in the tropical conditions limestone formed, more often than not as the result of organic activity. As organisms died, their shells became incorporated into the limestone layers that dominate mountain ranges surrounding Death Valley. The formations ultimately reached a thickness of at least 20,000 feet. There are mountains of animals!
Erosion has ripped away the rocks and deposited them in widespread alluvial fans, and the remains of the ancient creatures can be viewed in the rocky detritus. The students were interested in searching for them. The urge to collect can be powerful, and that's illegal in a national park, so we headed east towards the park boundary on the road to the Amargosa Valley and Death Valley Junction. When we stopped, the students scattered across the desert, not finding much at first, but soon there were cries of discovery. Horn corals (below), crinoid or blastoid columns (the next picture after), brachiopods, bryozoans, gastropods, and even an occasional cephalopod.
 Some of the samples were quite showy!
Occasionally I looked up towards the forbidding peaks of the Funeral Mountains and contemplated how many creatures lived, struggled and died to make up the many thousands of feet of carbonate rock in the slopes above. Untold trillions...

1 comment:


Captures the spirit within a geologist who tries to connect to the ancient past inspire of very engaging present. Good description style, pleasant to read.