|Map showing locations (in red) of the distinctive granite that has been offset by the San Andreas Fault in Southern California. The arrows show the relative sense of offset along the sides of the fault. Artwork is by R. Squires.|
|An exceptionally large crystal (4.5 cm length) of orthoclase from the Mill Creek Canyon locale.|
Geologists refer to localities that show precise offsets along faults as "piercing points." Liebre Mountain is 100 km northwest of the Mill Creek area. This distance of offset is less than the generally accepted distance of about 240 km of offset along the San Andreas Fault.
Several years ago, I noticed a boulder-size piece of granite in the office of one of my colleagues, Dave Liggett. Over the years, I kept admiring the rock, and, one day, he kindly gave me some nice representative specimens. These are the same specimens illustrated here, and they are from the Mill Creek Canyon locale. He also provided the background story of this rock.