Cover photo from Geology, January 2012, v. 40, no. 1 (http://geology.gsapubs.org/content/40/1.cover-expansion).
“Aerial photograph of the Greendale fault surface rupture resulting from the 2010 Mw 7.1 Darfield (Canterbury) earthquake in New Zealand. Rupture morphology consists of a dextral fault zone dominated by en echelon Riedel and Riedel-prime shear fractures that displace agricultural features such as fence lines and drainage canals. North is to the right in the photograph; sheep provide a scale. “
dextral fault: A fault where the block opposite you moves to the right; a right-slip fault. In this instance, the fault is a zone containing other faults aligned at an angle to the bounding fault structures.

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