A photo of Temblor Range

This view is looking east from Painted Rock toward the Temblor Range. The trace of the San Andreas Fault and northern Elkhorn Hills escarpment are midway across the right side of the image about halfway across the valley.

The Temblor Range and surrounding region contains extensive outcrops of the Miocene Monterey Formation (Dibblee, 1972 and 1973). Rocks from the Monterey Formation consist mostly of siliceous shales and porcellanite. Fossils and sediments from the Monterey Formation show that the Carrizo Plain region was once a marine basin with shallow to intermediate depths. Even younger marine sediments occur throughout the Kettleman Hills region (about 60 miles north of the park) where the Etchegoin Formation contains marine fossils as young as about 4 million years old (Pliocene Epoch) (Woodring and others, 1940). Therefore, the Coast Ranges and the Temblor Range are young features, uplifted in the past few million years. Much of that uplift, which is still occurring, is associated with the San Andreas Fault and related faults in the region.