Geography The Point Arena Terrane is a tectonic unit of geologic formations and sedimentary landforms west of the San Andreas Fault on the northern California coast, and is traveling northwestward along the transform plate boundary. The Point Arena peninsula, headlands, and coastal slope are a series of tectonic marine terraces, steadily and rapidly uplifting from … More Living Landscapes: Point Arena’s Sedimentary Complex, Tectonic Geomorphology, and Biogeographic Setting