DeRose-Cienega-Almaden Winery

Steven Dutch, Professor Emeritus, Natural and Applied Sciences, Universityof Wisconsin - Green Bay

This used to be the Almaden Winery, then later the Cienega Winery, and since 1988 it has been the DeRose winery. In the map above, faults are in red. The San Andreas and Calaveras Faults are accented with light blue. The San Andreas Fault is creeping here; the Calaveras Fault is creeping inHollister. The winery may produce fine wines, but to geologists it's world famous for having its main building smack astride a creeping segment of the San Andreas Fault.

Looking north at the main building, June 2002.
On this wall the principal evidence of fault motion is the warped shingles above the roof of the annex. There doesn't seem to be much evidence of change between June, 2002 (left) and February, 2007 (below).
And here's the world famous culvert.

World famous culvert?

Yes. This culvert has been offset by about a foot and is depicted in many geology texts.

Winter is definitely better for photographing this feature. The offset is plain in this February 2007 shot; summer growth obscures a lot of detail in the June, 2002 photos below.
Left and below: Back in the Sixties this hill was planted with vines that displayed beautifully offset rows. The vines have been cleared and it will be a long time before the new vines grow and are offset. The steep slope in the road marks the fault scarp.
The north wall of the main building shows the most dramatic offset. Again there doesn't seem to have been much change between 2002 (first three pictures) and 2007 (last four).

Fault creep tends to be episodic. A row of en echelon cracks in a street in Hayward on the Hayward Fault remained unchanged from 1968 until into the 1980's (the street has since been repaved).

Left and below: cracks in the pavement north of the main building.
Views looking south toward the winery. The valley marks the fault zone. The present creeping fault trace through the winery building is only the currently active break.
Looking north up the fault valley toward the winery.
Looking south along the fault valley.

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Created 15 January 2007, Last Update 06 June 2020