Tuesday, October 23, 2007
Deep Cores Recovered from San Andreas Fault Give Clues to Fault Behavior
USGS, NSF and Stanford geologists have recovered rock core samples of the San Andreas Fault 2 miles beneath the earth's surface. The cores were advanced using drilling technology borrowed from the oil industry. 135 feet of 4" diameter cores were recovered and high resolution images are available for viewing here. These samples are the first intact samples of this type ever recovered. The geologist will use these samples to try to determine the exact chemical processes that allow the SAF to creep along while "most of the fault moves in violent, episodic upheavals."