Annual Meeting - SCEC.org

Extreme Ground Motion (ExGM)
Group 1 – ExGM | Poster Abstracts
1-062
A COMPARATIVE ASSESSMENT OF THE GEOMORPHOLOGIC SETTING AND
GEOLOGIC CONTEXT OF ZONES OF PRECARIOUSLY BALANCED ROCKS IN
LOW-SEISMICITY REGIONS Haddad DE, and Arrowsmith JR
The utility of precariously balanced rocks as negative indicators of previous strong ground motion
has proven to be promising in seismically active regions of Southern California and Nevada.
Understanding the geomorphic context and processes that control the production and preservation
of precariously balanced rocks is essential to any analysis of precarious rock zone. This study
compares the geomorphic and geologic context of four precarious rock zones (Granite Dells,
Chiricahua National Monument, Texas Canyon, and Granite Pediment) in low-seismicity regions
of Arizona and Southern California. The Granite Dells locality is a ~20 km2 Proterozoic granite
field that is ~5 km from the Prescott Valley graben faults (