The Alpine Fault from Lake McKerrow to Milford Sound

Abstract

The Alpine Fault intersects the west coast of the South Island of New Zealand about four miles north of Dale Point at the entrance to Milford Sound; moraine on the west of the fault has beeili faulted against Fiordland Gneiss on the east, A well defined fault trace was followed from the air from the south side of Lake McKerrow through the east side of a huge eroded crush zone in the Kaipo River to the contact between moraine and gneiss at Stripe Point. The fault trace interrupts topography that probably formed during the last glaciation. The major displacement is dextral transcurrent and similar in direction and amount to that on the fault in the north, the valley of Kaipo River being displaced about a mile. The Alpine Fault is thus a major transcurrent fault at its southern limit on land with essentially the same character as along the western side of the Alps to the north.