Rocks!

Coleman Valley Road, Occidental
to Arch Rock Beach
Carmet, CA
Sonoma County

Occidental is a one drag town with three bars, a couple restaurants and home collectible stores. I have been told that at scene from Hitchcock's "The Birds" was filmed here, but I have not confirmed the same to be a fact. Maybe it was Vertigo ... but I digress. From the main street in Occidental there is a road called, Coleman Valley that heads west out to the coast. The drive is crooked and winding and if you don't happen to see the small hand painted wooden directional sign that reads "Ocean" you may miss the turn and head south towards the Bodega Highway. The drive out to the coast takes approximately thirty minutes from Occidental, but the drive goes quickly and the scenery is lovely--picturesque even. Barns, an old school house and cows dot the landscape as you drive through densely wooded expanses and into open meadows on your way to the apex of the hills. Once atop the rolling range, the scent of California sage brush lightly floats in the air indicating that the coast is near!


Soon enough the sage gives way to unencumbered green hills with few trees & shrubs gathered only around small waterways. A few granite outcroppings (rocks!!) can be seen which are indicators of ancient subduction zones. Subduction zones occur when two plate boundaries meet & converge. The more dense plate sinks or is subducted underneath the more buoyant plate. Oceanic crust is denser than continental crust and therefore is subducted under the continental plate to be absorbed back into the mantle. As the sinking plate is subducted the rock material breaks down, water is released which lowers the melting point of the mantle to produce magma. This magma then rises towards the earth surface and can result in a volcanic eruption. Over geological time the magma chambers cool and crystallize forming rock such as granite. As the materials around the chambers erode over millions (MILLIONS) of years, the granite becomes exposed. The granite in the Seirra Nevada's is estimated to be approximately 100 million years old--closer to the coast the rocks are dated at approximately 60-90 million years old. The next time you see a granite outcropping it is likely the site of an ancient volcanic arc--presently viewing the past.





The descent from Coleman Valley is a severe and dramatic drop to a little town called Carmet just south of Jenner. Carmet is home to Arch Rock Beach where many sea stacks and sea arches can be observed. Sea stacks and arches are the remnants of headlands worn down by wave energy. Sea arches form when the waves are directed around the end of a headland and crash on both sides form sea caves which eventually meet up! Once the sea arch falls, it becomes a sea stack. Stacks and arches are evidence of where the headland boundary once lived!



Photos = Joshua R. Neely

Heart's Desire / Tomales Bay

January 17, 2011: Heart's Desire Beach, Tomales Bay State Park
Iverness, California

Heart's Desire Beach is a lovely stretch of taupe colored sand lined by a flat grassy area with wooden picnic tables and iron bbq pits. The entrance to the beach area is flanked by hillsides covered in Bishop Pines with minty green moss hanging like tinsel from their branches. According to the Point of Interest (POI) informational board, the pines depend on natural lightening derived fires for their survival. Lightening strikes the wooded area generating a fire which causes the seeds to pop from the Bishop Pines and fall to the ground, thus completing the circle of life! The fires also serve as a way to clear brush and make way for new baby trees.

Facing Tomales Bay from Heart's Desire there are paths leading into the forested areas on both the left and right sides. We chose the path to the right which lead to Shell Beach less than a mile away headed inland (East?). The path began with a dark wooden staircase which eventually gave way to a black earthen path surrounded by ferns. While we heard many birds, the dense shrubbery provided excellent camouflage and very few were observed. Although, a few tiny bush tits (?) flitted overhead.

After climbing the path, we descended upon Shell Beach, which was at that moment experiencing a low tide exposing a muddy and grassy shore. The sea grass blades were a vivid lime green but laid limp without the salty water to provide support. Sea grass differs from sea kelp (algae) in that it is a plant with roots and seeds. Closer to the backshore, we observed rocks encrusted with muscles, chitons, and anemones retracted into their squishy mouth openings.

CRISIS OF OF IDENTIFICATION

Along the waterline, I found a few curious little creatures, that I still cannot with certainty identify. The creatures in question were about the size of a quarter, bright orange with brown spots and with an abalone like consistency (malleable rubber). At first I thought it might be a type of jellyfish (phylum Cnidaria), but now I am having doubts. Any ideas??

Another peculiar find was a piece of bone vertebrae, we think belongs to a pelican. On this day, we witnessed two large pelicans diving with rapid speed into the bay like a reverse rocket ship breaking into the ocean.





I am fairly certain that my last specimen within the identification crisis section is a sea sponge, but am not wholly sure. The sea creature was covering a rock, very porous and golden orange in color.


MORE OCEANIC FINDS!

On this day, we found over 25 dead salad plate sized jellyfish scattered along the shoreline. These jellies were clear with deep purple gonads! Yes, jellyfish have gonads! I have no idea why there were so many and why they were dead. Sadness.

Against the hillside, a portion of the stratum was exposed showing the geological history which included a layer of burned wood. The area was once known to be inhabited by the Miwok Indians, perhaps the find is evidence of the tribe's occupation of Tomales Bay! The wood is clearly sandwiched between two layers of rock, and part of the stratum.

As the sun started setting and the tide rising, it was time to head back to Heart's Desire and our vehicle. Instead of walking back along the trail, we opted to traverse the shoreline where we were followed by two seals swimming in the silvery water.

Between Heart's Desire & Shell Beach is an expanse of clam bed! Clams are bivalve mollusks that thrive in densely packed beds of rock & sand (according to the other POI). The tide was still very low and the clams were squirting water through their siphons causing a water show rivaling that of the Bellagio.



All photos taken by Joshua R. Neely