“Tomales Bay lies about 50 kilometers (30 miles) northwest of San Francisco, along the edges of two tectonic plates that are grinding past each other. The boundary between them is the San Andreas Fault, the famous rift that partitions California for hundreds of miles. To the west of the Bay is the Pacific plate; to the east is the North American plate. The rock on the western shore of the Bay is granite, an igneous rock that formed underground when molten material slowly cooled over time. On the opposite shore, the land is a mix of several types of marine sedimentary rocks. In Assembling California, John McPhee calls that side “a boneyard of exotica,” a mixture of rock of ‘such widespread provenance that it is quite literally a collection from the entire Pacific basin, or even half of the surface of the planet.'”


Tags: geomorphologyremote sensing, tectonics, geology, Californiacoastal, physical.

Source: earthobservatory.nasa.gov