Width of the Alpine Fault Zone, New Zealand

Abstract

The Alpine Fault of New Zealand is sometimes thought to be very narrow in comparison with other strike-slip faults of large displacement. This is in part due to restriction of the term “Alpine Fault” to a single fault in a zone consistmg of several faults and in part to an assumption that the active fault, the mam lithologic break, the physiographic break, and the fault with the largest net slip are the same. Because of lack of exposures and incomplete mapping, this assumption has not been proved. In contrast, physiographic evidence and the available exposures suggest a zone of faulting generally ½–1 mile wide.