It’s written in stone

Beginning about 145 million years ago, and lasting for over 100 million years, sediment eroded from the North American continental plate into the ocean on the ancestral Pacific plate. Over time this sediment hardened into layers of Franciscan sandstone and shale.

…the foundation for the complex ecosystems that exist at Point Molate.

The rocks at Point Molate are called Novato Quarry terrane, one of several types of Franciscan rocks found in the Bay Area. The same rock can be found on the opposite side of the Bay, demonstrating that Marin County and Point Molate have a shared ancestry. These rocks provide the foundation for the complex ecosystems that exist at Point Molate.

Winter water

The watersheds at Point Molate extend from the spine of Potrero Ridge (at over 400 feet elevation) downhill to San Francisco Bay. Most of the watersheds are rocky, except for the sand beach and the mudflats at the Bay shoreline. Rainwater falling on Point Molate cascades down the hillside to the Bay along stream beds that are dry in the summer. Originally, all of these open stream beds led directly to the Bay, but as buildings were built and paving was installed, culverts were used to carry water underground at several locations. Unfortunately, culverts cut off light to the plants and animals that live in streambeds, and they also prevent human enjoyment of running water. A more recent practice called “daylighting” is designed to restore light to such streams so that natural systems can regenerate.

Photo Credits: Jack Scheinman