Abstract

Long normal faults (typically >70 km in length) are rarely planar, but contain significant along-strike geometric bends. Significant geometric bends may form during segment linkage where two originally isolated faults connect. Segment linkage may occur along underlapping or overlapping faults. An important subset of overlapping faults results in fault capture. The purpose of this paper is to show that each type of linkage generates a displacement – distance profile with a different shape. Linked underlapping faults display a symmetric displacement pattern with a relatively sharp change at the minimum. Linked overlapping faults show a similar pattern, but with a bench of relatively constant throw along the linkage zone. Fault capture forms a more complicated pattern with a plateau along the captured fault segment, a steep displacement gradient and then a decrease in displacement. Analysis of fault geometry, footwall elevation – distance profiles, and displacement – distance profiles allows development of a segment linkage history for a portion of the Hurricane fault. This fault lies along the transition zone from the Basin and Range province to the Colorado Plateau in southern Utah and northern Arizona. Our analysis suggests that the northern portion of the Hurricane fault formed by the linkage of at least three originally isolated faults. The Toquerville geometric bend formed during linkage of two underlapping faults and the State Line geometric bend formed during fault capture.