Death Valley geology field trip
Artist's Drive |
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Technicolor terrainThe face of the Black Mountains along Artist's Drive is made up of the multicolored rock of the Artist Drive Formation. Aprons of pink, green, purple, brown, and black rock debris drape across the mountain front, providing some of the most scenic evidence of one of Death Valley's most violently explosive volcanic periods. Roller coaster rideThe curvy, one-way, one lane Artist's Drive leads you up to the edge of the Black Mountains. Artist's Drive rises up to the top of an alluvial fan fed by a deep canyon cut into the mountain. As you make your way up to the mountain face you'll dip up and down, roller coaster-like as the road dips into ravines carved into the fan by Death Valley's occasional, but intense flash floods. The narrow road runs high up onto the fan, with views of the strikingly white salty floor of Death Valley in the distance. On your way out look for steeply dipping beds and cuts into alluvial fans that reveal the internal structure. Countless floods created layer upon layer of sand and gravel. If you look at the older fans near the exit you'll notice that the boulders composing the fans appear black. pick up one of the boulders, the underside is lighter. This is desert varnish. The Miocene Artist Drive Formation is made up of cemented gravel, playa deposits, and much volcanic debris, perhaps 5,000 feet thick. Chemical weathering and hydrothermal alteration are also responsible for the variety of colors displayed in the Artist Drive and Furnace Creek Formations. Brick-reds and pinks are due to the presence of iron-rich hematite which oxidizes. Shades of golden to pale yellow also result from varying amounts of different types of iron oxides. The green tuff are altered volcanic ash deposits. |
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