Wednesday, May 13, 2020
Las Vegas Geology Highlights
The glittering city of Las Vegas has done all it can to blot out the desert. But the region is a wonderland of natural attractions, too. Start with the Desert The American desert is a world-class destination all by itself, of course. Its such an iconic setting, familiar from Western movies, music videos, and car ads, that it feels like home even the first time you go there. Any place in the desert is special, but there are really noteworthy sites near Las Vegas. As you arrive, look around and drink in the sight of endless stone. Las Vegas Valley is a downdropped basin typical of hundreds in the Basin and Range, the geologic province that extends over all of Nevada and a little beyond it on all sides. Over the last 25 million years or so, the Earths crust here has been stretched in an east-west direction to around 150 percent of its former width, and the surface rocks have broken into strips of mountains running north-south. As a result the hot material beneath has bulged upward, turning Nevada into a high plateau rich in metal ores and geothermal energy. Numerous earthquakes have been recorded there during this century as the areas tectonic activity continues. The high elevation and the upwind barrier of the Sierra Nevada and Cascade Range on the west has made the Basin and Range a very dry place, one where the mountains remain bare and settlements sparse. Typical desert landformsÃ¢â¬âplayas, dunes, desert pavement, arroyos, alluvial fans and bajadasÃ¢â¬âare plentiful, and bedrock outcrops and fault traces are well exposed. Geologists love deserts. Just Add Water Las Vegas was once a small settlement named Bringhurst, but it got its current name from the grasslands (las vegas, the meadows) that once grew in the valley. In the desert, grass represents a shallow water table, and in the Las Vegas Valley grass was a sign of the natural faults that force the water table near the ground surface there. Las Vegas languished as a tiny railroad town, serving the nearby mines, until the Colorado River was dammed to create Lake Mead in the 1930s. The city has also exploited the aquifers beneath the Las Vegas Valley so that even if the city vanished tomorrow, the meadows would not return. The availability of enough water to boat in and fill pools helped turn Las Vegas into the tourist destination it is today. While the Las Vegas Strip makes spectacular playthings out of water, the rest of the city tends to landscape itself in gravel and cactus. The University of Nevada campus here is an elegant example of this approach, and worth a visit just for the grounds. The geology department building has hallways lined with display cases full of excellent rock and mineral specimens, too. Las Vegas Geologic Sites There are many beautiful places to see while youre in town. Three great national parksÃ¢â¬âGrand Canyon, Zion and Death ValleyÃ¢â¬âare within reach for budget travelers, but let me focus on places nearer Las Vegas. Just west of the city is Red Rock Canyon Conservation Area, a prime destination for rock climbers. But you can just take a slow drive through the colorful formations if you like. One of the geologic highlights is an excellent exposure of the dramatic Keystone Thrust, where ancient crustal motions 65 million years ago shoved great thicknesses of gray limestone on top of younger beds of red sandstone. An hour or so northeast of Las Vegas is Valley of Fire, Nevadas first state park. The geologic setting is similar to Red Rock, but in addition this park features many ancient petroglyphs, rock art left by the local tribes including the mysterious Anasazi. Take my Valley of Fire tour here.About.coms Betsy Malloy has her own photo tour.Heres visitor information for Valley of Fire daytrippers.Try a guided 4WDÃ of Valley of Fire. Both Red Rock Canyon and Valley of Fire are places that display the Sevier Thrust Belt, a gigantic zone of tectonic upheaval that stretches from the Las Vegas area into Canada. The thrust belt records a continental collision far to the west, on the continents edge, during Cretaceous times about 80 million years ago. There are other places near Las Vegas where you can see its signs. To the north of Las Vegas is the understated Upper Las Vegas Wash, where locals come to get away from it all while geologists come to explore the rich fossil record. Take a visit. To the south, you can take trails down to the Colorado River valley below Hoover Dam. And many more destinations are listed in my Nevada Geology category. Maybe a desert hot spring or an all-terrain vehicle tour is more to your liking. Given all these possibilities, Im about ready to go live there full time myself. PS: Among the people who DO live there amidst the tinsel and the scenery are some righteous salt-of-the-earth types, proud of their small desert towns. After youve had your fill of Las Vegas, why not unwind in a quiet little place like Blue Diamond, Nevada, the town that sheetrock built.