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Unearthly world-Death Valley's badlandsLooking out from Zabriskie Point, you are surrounded by yet another of Death Valley's forbidding, almost unearthly, desert landscapes. These are badlands. Everywhere you look, you see bone-dry, finely-sculpted, golden brown rock. Only the sparsest vegetation can survive in this intricately carved terrain. What processes work to form this spectacular scenery? Surprisingly enough, the story of Death Valley's badlands begins and ends with water. A muddy beginningAt Zabriskie Point, the badlands are developed on a mudstone foundation (Furnace Creek Formation). Fine-grained sediments (silt and clay) were deposited in one of Death Valley's prehistoric lakes, then were buried by still more sediment, and finally compressed and weakly cemented to form the soft rock called mudstone. If you took a microscopic look, you would see that the clay minerals in the mudstone are shaped like tiny plates. These plates act like roof shingles, preventing water from penetrating the surface. The combination of the almost impermeable mudstone and Death Valley's scant rainfall makes plant growth and soil development nearly impossible. |
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Water: the continuing sculptorNow, back to the role of water. At Death Valley rainfall is intense but sporadic. Very long periods of drought are punctuated with drenching downpours. With so little vegetation and no soil, when water reaches the ground, there is nothing to absorb the rainfall. During Death Valley's rain showers, water hits the surface and immediately begins to rush down the steep slopes, sweeping along particles of loosened mud. The rate of erosion can be incredible! Tiny rills are quickly carved into the soft mudstone. The more water in the downpour, the more rills are needed to carry the water away. Rills cut deeper to form gullys. Badlands are the ultimate result-nature's way of efficiently moving lots of water quickly. |
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