On Sunday D. and I went to the Don Edwards San Francisco Bay National Wildlife Refuge in Fremont to attend a program led by Ranger José Garcia explaining how geology influences the local landscape and helps rebuild wildlife habitat. Here are some of the pics I took.
The visitor center.
Tiny fossil seashells can be found in this rock near the parking lot, because it came from an ancient seabed before being lifted up into a mountain.
Photinia is in bloom at the refuge.
Gumplant is a common native wildflower found near salt marshes.
Ranger José explains the provenance of a rock beside the road.
I forgot everything Ranger José told us about this rock (I think it's chert?), except it's really old and has portions of primeval magma embedded in it.
It's for the birds.
Ranger José explains radiolarian chert, a common rock in the San Francisco Bay Area. It is formed by the silicon exoskeletons of microscopic diatoms that sink to the ocean floor and eventually turn into rock. Bands of different widths show yearly accumulation.
It's Mother Goose! And Father Goose and Baby Goose in a slough at the refuge.
A turkey vulture soars overhead.
Looking east from the Tidelands Trail.
The blue rock is blue schist.
Looking north from the Tidelands Trail.
Looking west over former salt ponds toward the Santa Cruz Mountains.