Santa Monica Formation


The oldest rock formation in the Santa Monica Mountains is exposed in the roadcuts along Mulholland Drive for the first 2 miles of this leg of the hike. The rock unit is referred to as the Santa Monica Formation and it is composed of a dark gray, mildly metamorphosed slate. A few fossils still preserved in the slate establish the age as Late Jurassic, about 150,000,000 years old.

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