Interpretation of magnetic anomalies across the Campbell Plateau, south of New Zealand

Abstract

Magnetic anomalies over the Campbell Plateau show up a linear belt of positive anomalies extending for 900 km with an approximate east?west trend. This belt is identified as part of the Stokes Magnetic Anomaly System which extends throughout New Zealand and is associated with rocks of the New Zealand Geosyncline. The system defines a trans-current fault with a dextral displacement of 330 km which can be traced from the SW tip of the Campbell Plateau to the Bounty Trough in the north. Restoration of this Campbell Fault requires the Bounty Trough to be a rift feature, probably associated with Indian-Pacific plates' movements during the Miocene or Oligocene. The extension of this boundary may have been a subduction zone running from the NE tip of the Campbell Plateau past the North Cape of New Zealand to the Norfolk Ridge, along what is now the southern margin of the South Fiji Basin.