Stratigraphic Evidence for 7 Meters of Dextral Slip on the San Andreas Fault During the Great 1857 Earthquake in the Carrizo Plain
The smallest geomorphic offsets along a 35 km section of the San Andreas fault in the Carrizo Plain vary from 7 to 10 m. Our three-dimensional excavation of alluvial deposits a few km southeast of Wallace Creek confirms that at least 6.6 to 6.9 m of dextral slip occurred there during the latest large earthquake, in 1857.
Grant, L. and Sieh, K., 1993, Stratigraphic evidence for 7 meters of dextral slip on the San Andreas fault during the great 1857 earthquake in the Carrizo Plain: Bulletin of the Seismological Society, v 83, 619-635.
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Email Address Created for Land Exchange Questions
The Southwestern Region Office of Lands and Minerals Management is overseeing and administering the land exchange and appraisal process which includes the 2,422-acre Oak Flat Federal Parcel. All questions about the land exchange and appraisal process should be emailed to SM.FS.rcexinfo@usda.gov
Programmatic Agreement Info
To comply with Section 106 of the National Historic Preservation Act, the Tonto National Forest developed a Programmatic Agreement (PA) and included it in Volume 5, Appendix O of the final EIS. The PA was created in cooperation with the Advisory Council on Historic Preservation, the State Historic Preservation Office, tribes and other consulting parties. The PA contains an agreed upon process for identifying, evaluating and addressing adverse effects to historic properties associated with this undertaking.
To review Volume 5 and the PA, Download Vol 5 PDF, 27 MB.
Forest Service Point of Contact
John Scaggs
Tonto National Forest
john.scaggs@usda.gov
Apache Leap Special Management Area
Apache Leap SMA website