GeoSnaps - Image of the Day
Geologic snapshots capturing Arizona’s geologic setting and mining history with a picture of the day from 1 January through 31 December 2013.
Santa Catalina Mountains | Pima County, AZ
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.)