Place: Carrizo Plain National Monument
Coordinates: 35.271418, -119.827378
Length: about 1 mile
The San Andreas Fault (SAF) is the large geological fault that cross-sections California from Salton Sea (south) to Eureka (north), the meeting line of the Pacific and the North American tectonic plates. There are many places where the San Andreas is apparent on ground level, but none more so than in Carrizo Plain National Monument. It is a given than when visiting that park, we had to make pilgrimage to the site where the SAF makes its most obvious appearance: Wallace Creek.
|An aerial photo of the SAF at Carrizo Plain NM, snipped from Google Earth|
Carrizo Plain is a basin that is bordered with the Caliente Ridge in the southwest and with the Tremblor Range on the northeast. We arrived early at the Wallace Creek parking lot and took the trail to the low hills below Tremblor Range.
|Little Bear Scarab|
|Salinas Milk Vetch (Astragalus macrodon)|
This bend is the work of the San Andreas Fault. SAF is a right-lateral strike-slip (transform) fault, meaning its edges slide against each other on the same level, and each side is moving to the opposite's right. That is, the western side of the SAF is sliding north while the east side moves south.
The 10 million yo SAF moves about 1.5-2 inches per year.
That movement created bends in west-bound Tremblor creeks that cross the fault. It shows beautifully in the Wallace Creek bend.
On our previous visit there Papa Quail had seen a roadrunner zooming on the hillside. I didn't post that photo back then because it is blurry. (It run fast!) It was an unexpected encounter: Carrizo Plain isn't where I expected to see roadrunners. But it is on the birds checklist for Carrizo Plain, and it would still be an exciting sighting there. We didn't see any roadrunners last April, so I am posting that blurry photo from January 2013 of the roadrunner at Wallace Creek.
Going back to the car I took a closer look at the dry plants by the trail. By their shape I could tell they were fiddlenecks. It must have been really pretty there when all of them were in bloom. I wonder when was the last time that happened.
Papa Quail was at the driver's seat and I stopped him countless times so I could get off and photograph a flower I saw from the car.
There were the fiddlenecks. Up on the ridge they were green and blooming.
Roadside botany is not compete without leaving the car.
|San Joaquin Blazingstar (Mentzelia pectinata)|
|Carrizo Plain and Caliente Ridge|
|Taft and the Jan Joaquin Valley|
|Many-flowered Eriastrum (Eriastrum pluniflorum)|
Then we saw some birds on the fence and Papa Quail slammed the breaks. They were blackbirds, and all blackbirds look the same to me: pretty and sweat singers, but not worthy of a special stop.
But Papa Quail detected something I didn't notice: these birds had a white stripe on their wing. They were tricolored blackbirds.
I eagerly wait for a good rainy year. It won't take much to get me down to Carrizo Plain NM again. I don't think that carpets of wildflowers is too much to ask for.
Many thanks to members of the California Wildlife Appreciators group for their help in identifying the crane fly!