THE KAKAPO FAULT - A MAJOR ACTIVE DEXTRAL FAULT IN THE CENTRAL NORTH CANTERBURY - BULLER REGIONS OF NEW-ZEALAND

The Kakapo Fault is a major active dextral fault, which may be no older than 250 ka. This is much younger than the well-known Hope Fault. Judging from its geological and geographical appearances the fault is close to vertical. Displaced river terraces at Kakapo Brook east of Lake Summer indicate a dextral rate of 6-6.8 mm/yr, while displaced streams west of Lake Summer indicate a rate of 8.1-12.1 mm/yr. This is an addition to the rate of movement across the Marlborough faults. If the rates for other Marlborough faults are accepted, the total dextral rate across them (including the Porters Pass Fault) would be about 38 mm/yr, which is about 81% of the relative plate movement. Thus there may be only one-fifth of the relative plate movement accommodated by other forms of deformation in the northern part of the South Island.