I went for a hike this morning up Poly Canyon. I went the long way around, from the back of the hill, rather than going straight from my appartment up to the top.
Here's my "the sun is in my eyes so I am going to count to three then open them right when I take the picture" look.
Poly Canyon Hike 21July2012_ 017 by
Max_911S_fahrer, on Flickr
I don't know what they do up here, but it isn't English homework!
Poly Canyon Hike 21July2012_ 034 by
Max_911S_fahrer, on Flickr
This blue-green rock is Serpentinite, the state rock. It is very pretty and is everywhere up in the SLO area it seems. It is formed near undersea subduction zones when mud minerals get compressed under the plate and then get chemically changed by hydrothermal vent action. California used to have a subduction zone like the one in Oregon. The Sierra Nevada are the volcanoes from that subduction zone, but they are inactive, unlike the volcanoes in the Pacific Northwest.
The SLO area was part of the undersea subduction zone and you can see ancient pillow bassalts (as one can see forming in Hawaii) on Avila Beach. The Serpentinite we find here is from the hydrothermal vents and has been uplifted by the change in fault motion from subduction to the sliding action of the San Andreas, which has formed the coastal mountain ranges due to wrinkling of the plates caused by friction at the sliding boundary.
The conical mountains that are SLO's distinctive feature are volcanic in origin and are a result of the Farallon Plate being fully subducted and relieving pressure on the mantle, causing lava to come to the surface much like a bottle of soda or beer after being shaken and opened. They are therefore made of a much different rock than the Serpentinite.
Poly Canyon Hike 21July2012_ 037 by
Max_911S_fahrer, on Flickr
Poly Canyon Hike 21July2012_ 039 by
Max_911S_fahrer, on Flickr
Poly Canyon Hike 21July2012_ 040 by
Max_911S_fahrer, on Flickr
Poly Canyon Hike 21July2012_ 051 by
Max_911S_fahrer, on Flickr
It is a bit steep:
Poly Canyon Hike 21July2012_ 035 by
Max_911S_fahrer, on Flickr
Here is a panorama:
All sizes | Poly Canyon Pano | Flickr - Photo Sharing!