Day #120 Deskcrop: Bear Valley Springs Tonalite

We’ll close out the week and the month back in California with a deskcrop and thin section of the Bear Valley Springs Tonalite, one of the more abundant granitoids from the southern end of the Sierra Nevada Range in the Tehachapi-Bakersfield region. I’m not at all certain of the exact locality of this sample, but I strongly suspect that I collected somewhere along the Kern River Canyon between Caliente and Lake Isabella. It’s a run-of-the-mill Sierran tonalite, and a classic I-type granite with both hornblende and biotite as varietal minerals. The age of the BVS tonalite is right around 100Ma.

Bear Valley Springs Tonalite

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