Sets of geologic features that can be treated as points on maps may be underlain by, and owe their position to, hidden linear crustal fractures. We present two complementary quantitative methods for determining the azimuthal directions of such aligned points applied to a field of cinder cones in southwestern Mexico, the Michoacan-Guanajuato volcanic field. The two-point azimuth method is probabilistic and corrects for the bias of the areal shape of the field before testing for overall structural anisotropy at a regional scale. The Hough transform method searches the field locally and simulates the human visual capability of joining aligned and nearly aligned points. Our results for the Michoacan-Guanajuato volcanic field show that although the shape of the field is elongated northeasterly, the regional structural anisotropy is northwesterly. Locally, easterly trending alignments of volcanic vents are the most common alignments detected by the Hough transform method.

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