Geotectonics and the New Zealand Geosyncline

ONE interpretation of the New Zealand Geosyncline (Carboniferous-Jurassic) envisages a pair of elongate north or northwest trending sedimentary realms-the Hokonui realm (facies belt) lying to the northeast of a granitoid foreland, and the Torlesse realm further to the northeast facing the Pacific1,2. The Hokonui realm is characterized by moderately fossiliferous, structurally simple marine and subsidiary non-marine sediments. Andesitic volcanics and volcanic derived elastics are typical; granitoid foreland derived material is subsidiary and concentrated in near-shore western sections. The Torlesse realm is said to be characterized by deep water, "redeposited" or turbidite sediments. It is characterized by an acid plutonic detrital suite which is said to be derived from the western granitic foreland and transported across the Hokonui realm either in submarine canyons or by some other "by-pass" mechanism.