K/Ar ages from the volcanics of Northland, New Zealand

Abstract

Fourteen samples of basalts, andesites and a dacite from the major Tertiary volcanoes of Northland were K/Ar dated. Ages ranged from 18 · 0 m.y. to 0 · 017 m.y. with good agreement with the geologically determined ages. Maximum and minimum ages of 16 m.y. and 4 m.y. are placed on the active period of the Kaikoura Orogeny in northern New Zealand.