Deserts are extraordinary. I must tell you from the beginning that deserts are my natural environment. The world for me consists of dry, brown, dusty hills where I can see for miles under a brilliant sky. A place so dry the air plucks at your lips and the sand crackles under your feet. And there is always the wind and the sun. Every landscape is quickly divided into the shady and the sunlit, the wind-swept and the protected. The rest of the world with its trees and grass, rivers and lakes, clouds and rain, is an exception for me. The Mojave Desert is my homeland. I grew up in Barstow, California. Rainbow Basin is a place I had many childhood adventures. I have a passion for deserts, so team-teaching this course with my colleagues in the Geology Department is a rare privilege.
During this first week we will discuss the general setting of deserts and the basic geological processes which operate within them. Our initial definition of a desert is the simplest one: a place which receives less than 25 cm (10 inches) of precipitation a year. Deserts can be hot or cold (they are rarely moderate!), they can be filled with life or virtually lifeless (or actually lifeless if we consider Martian deserts), and they can be flat or mountainous. We will be considering the “non-polar” deserts, especially the large ones like the Sonoran, Sahara, Arabian, Atacama, Kalahari, Australian, Gobi, and many more which are lesser known (including the Negev in Israel where Wooster geologists have recently been working). We will often return to the starkly beautiful Death Valley of southern California.
Red Rock Canyon National Conservation Area near Las Vegas.
Geology in the News –
Tyrannosaurus rex is often in the news because it “was pretty much the most effective killing machine ever to have stomped the Earth.” An American paleopathologist claims it also played with its food. “Deductive reasoning leaves a single conclusion: the activity resulting in the tooth marks on the bones discussed herein fulfills the definition of play.” I’m not at all convinced, but it is our T. rex news of the week!
A strange “ice ring” 2 km across in Antarctica may mark a meteorite impact from 2004. What’s coolest is that infrasound measurements were used to locate a possible impact of a “house-sized” object in this region way back in 2007.
We will also have lots of fossil discoveries in China this semester, guaranteed. It is the hottest place right now for paleontological exploration. Here is the oldest flying fish ancestor from the Triassic of southern China. Wushaichthys itself may not have “flown” (we really should say “glided”), but it shows early features leading to that step.