by David Tanner, Leibniz Institute for Applied Geophysics (LIAG), Hannover, Germany
Beautiful outcrop of a fault surface that is completely covered in slickenside in the Corona Heights Park of San Francisco. Host rock is radiolarite and the slickenside are pure quartz. Outcrop is approx 20m high, 10cm scale bar lower left.
David Tanner (distributed via imaggeo.egu.eu)