Evidence for 115 Kilometers of Right Slip on the San Gregorio-Hosgri Fault Trend

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Science  13 Jan 1978:
Vol. 199, Issue 4325, pp. 179-181
DOI: 10.1126/science.199.4325.179


The San Gregorio—Hosgri fault trend is a component of the San Andreas fault system on which there may have been about 115 kilometers of post-early Miocene right-lateral strike slip. If so, right slip on the San Andreas and San Gregorio-Hosgri faults accounts for most of the movement between the Pacific and North American plates since mid-Miocene time. Furthermore, the magnitude of right slip on a Paleogene proto-San Andreas fault inferred from the present distribution of granitic basement is reduced considerably when Neogene-Recent San Gregorio-Hosgri right slip is taken into account.