Field examples of strike‐slip fault terminations in Mongolia and their tectonic significance

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Abstract
Deformation at the ends of large intracontinental strike‐slip faults that do not simply link other major structures often involves rotations about a vertical axis. We use earthquake slip vectors, surface rupture in earthquakes, and geomorphology to examine the ends of three major strike‐slip faults in Mongolia. In these places a simple pattern is seen, consisting of a thrust fault on one side, with a displacement that decreases away from the strike‐slip fault, consistent with local rotational deformation. Strike‐slip faults that terminate in this way allow the style of faulting to change spatially within a deforming area, for example, from dominantly strike‐slip to dominantly dip‐slip, while still accommodating the overall deformation required by larger‐scale regional motions. Such a change in fault style should also be accompanied by a change in the rotation rate about a vertical axis, which may be detected paleomagnetically. The kind of strike‐slip fault termination described here may have consequences for how large strike‐slip fxaults evolve and grow and for the variation in displacement along their length.