Death Valley 16: Devonian Fold

Image Commentary

The grand scale of Death Valley is hard to appreciate without having seen it for oneself. The park is as large as most of the center of England, stretching for hundreds of miles in either direction. Likewise, the geology is correspondingly grandiose. Here, in one of the higher valleys, we see a "cut-away" in one of the mountain sides, exposing the core of the mountain as the core of a large "whale-back" fold or "anticline" (upwardly folded rock strata). The upward folded rock strata we can see in the "cut away" here are Devonian in age, a mere 350 million years old, but they were folded as we see them today a very considerable amount of time later in the early Tertiary period some 50-20 million years ago. The rocks themselves are limestones that have been very deeply buried at some time in their history so that heat and temperature have caused the rock to "recrystalize" or become slightly "marbelized". Limestones are most typically the result of an accumulation of calcium carbonate rich sediments that are deposited in open ocean conditions, so in other words, the presence of these rocks is proof that 350 million years ago, the entire area was part of the precursor to the modern day Pacific Ocean.