In California, there is a wide range of geologic features that makes us stand out from the rest of the U.S.. We have earthquakes, landslides, mountains, deserts, and so much more. The San Gabriel Mountains, located just north of Claremont, California, houses a plethora of geologic features. One of the things that interests me about these mountains, is not the fact that the San Andreas Fault is located just behind them, but it’s the Claremont potatoes that originated from there. The Claremont potatoes are rounded granitic rocks that are roughly the size of a potato. When you are walking throughout Claremont, you might notice the vast amount of rounded, granitic rocks. They are placed along the Claremont colleges, and are used as statement pieces in the surrounding neighborhood. These rocks (or potatoes) once started out as huge boulders. If you drive up to San Antonio Canyon, you could see bigger version of these granitic rocks. But, because there is a creek (San Antonio Creek), they have been rounded out to the size they are and ended up in Claremont. At the base of the San Gabriels, you will find Claremont. Claremont is basically an alluvial fan. Think of an alluvial fan as a dumping ground for rocks and other materials that were transported by a body of moving water. Due to this moving creek, the boulders that sit at San Antonio creek got smaller and smaller, rounder and rounder, as they got closer to the alluvial fan (aka Claremont). As a result, you get a Claremont potato. Due to the San Antonio dam, Claremont wouldn’t be seeing any more coming their way. So, next time you’re in Claremont, and you stumble over a rounded, potato like, granitic rock, think about its journey, where it’s been, and how it came to be.

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