This granite in the Santa Catalina Mountains contains two lineations produced by shearing under high-temperature conditions. The hammer overlies the younger lineation. Farther to the right, a lineation with a trend that is about 10 degrees different indicates a different, earlier episode of shearing. (Photo by Jon Spencer.)
Online resources:
Bezy, J.V., 2016, A Guide to the Geology of the Santa Catalina Mountains, Arizona: The Geology and Life Zones of a Madrean Sky Island. https://library.azgs.arizona.edu/item/DTES-1552428346471-69
Spencer, J.E., 2006, A geologist's guide to the core complex geology along the Catalina Highway, Tucson Area, Arizona. https://library.azgs.arizona.edu/item/AOFR-1552429673312-319
Photographer: Jon Spencer
Photo Date: circa 2010
Photo Location Accuracy: Approximately Located