Airphoto lineaments and fracturing in the axial ranges of the central North Island, New Zealand

Abstract

Basement greywackes form the frontal ridge in the subduction complex associated with the active plate boundary a10ng the east coast of the North Island. Four main lineament sets, trending NW, N-S, NNE and NE can be recognized. All four correspond with faults mapped in the field. Some of the faults probably have been inherited from Cretaceous-Early Tertiary rifting of New Zealand away from Gondwanaland. Models proposed for causes which may have influenced the fault pattern are: (1) Riedel shear array; (2) dextral bending; (3) along-strike compression of the subduction complex; (4) down-dragging of the subduction complex.

Key Words:

• greywacke basement
• frontal ridge
• subduction complex
• fault sets
• Riedel shears
• dextral bending
• along-strikecompression
• down dragging