A Geologic Staircase--with Marine-Deposited Carpeting
Looking north towards Trinidad, you can see a sequence of abandoned marine terraces, or wave-cut platforms, rising inland from the sea in a roughly staircase formation.
Waves pound against the exposed shoreline cutting a vertical face over time. Wave action then planes smooth the sea floor at the base of the cliff, forming the flat surfaces of the next terrace ‘step.’ Marine sediments are deposited on the flat surfaces. These terraces rise up as the Gorda Plate thrusts under the North American Plate. They then become the vegetated, inhabited landscape you see today.
I wanted you to see what it's like to look to north from this point and see what this sign is talking about. I have been inspired by Mark P of CaniConfidimus to try to piece together a panorama, and this task was perfect. I haven't tried to do a panorama in years. This photo is three separate shots, showing Trinidad Head and Strawberry Rock, the abandoned seastack.
Trinidad Head is an erosion-resistant block of gabbro (similar to basalt in composition) in the Franciscan Complex bedrock— an assemblage of diverse rocks embedded in a soft matrix of sheared shale and serpentinite.
Strawberry rock, visible in the distance, is an abandoned, erosion-resistant seastack (composed of greenstone rock, a metamorphosed basalt), that rose with the surrounding land during periods of tectonic uplift. You can see present-day seastacks scattered along the coastline.
You have to click on the panorama and look to the right from Trinidad Head to see Strawberry Rock, and along the way notice those marine terraces. I've added the above close-up, in case you miss the rock. I think the interesting thing to consider when looking at a beautiful ocean landscape like this is the nearly unfathomable number of years it took to create this scene. And there, in a little rise is a formation so easily missed, a seastack: a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, formed by erosion. Stacks are formed over time by wind and water, processes of coastal geomorphology.
There's nothing quite like getting my weight-bearing exercise while walking along this stunning expanse of ocean, and learning something new all at the same time. Yes!
UPDATED on Wednesday, February 18
I wondered if it might be possible to hike to Strawberry Rock, so I googled around and found this incredibly interesting site. The seastack is located in a 2nd growth redwood forest. This link will take you to a website that shows the efforts by locals to save that forest. More beautiful naked people laying their bodies down for the earth.