Back to granite on Cima Dome

A granite exposure near Teutonia Peak on Cima Dome. Note our jackets and hands in pockets!

ZZYZX, CALIFORNIA–Our last stop of the rapidly-cooling day was on the huge Cima Dome east of Zzyzx in the Mojave National Preserve. The dome is so large (about 70 square miles) that it is impossible to detect when you are actually on it, but easily visible from miles away. It apparently is the eroded root of a granitic intrusion formed during subduction in the Jurassic to Cretaceous. The alkali granite exposed here is very similar to that of the Granite Mountains we saw yesterday.

Potassium feldspar crystals in the coarse alkali granite of Cima Dome.

The soil of Cima Dome is derived almost entirely from the underlying alkali granite.

About Mark Wilson

Mark Wilson is a Professor of Geology at The College of Wooster. He specializes in invertebrate paleontology, carbonate sedimentology, and stratigraphy. He also is an expert on pseudoscience, especially creationism.
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2 Responses to Back to granite on Cima Dome

  1. Thanks for a concise and easily understood primer on the Cima Dome. Frankly I don’t understand why anyone even bothered to name it. But now that it is named I feel compelled to include some mention of it in my video about the Cima Volcanic Field. Is it related to volcanism at all?

  2. Mark Wilson says:

    Thanks, Robert. Fascinating area. The granite is not directly related to the volcanic field. Good luck with your work!

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