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. http://repository.azgs.az.gov/uri_gin/azgs/dlio/1679
Spencer, J.E., 2006, A geologist's guide to the core complex geology along the Catalina Highway, Tucson Area, Arizona. http://repository.azgs.az.gov/uri_gin/azgs/dlio/360