Field characteristics, petrography, and geochronology of the Hohonu Batholith and the adjacent Granite Hill Complex, North Westland, New Zealand

Abstract

Detailed geological mapping, petrography, geochemistry, and geochronological studies in the Hohonu Batholith, North Westland, have identified 10 granitoid plutons emplaced during three intrusive episodes. The earliest episode is represented by a single dated Paleozoic pluton, Summit Granite (new) (381.2 ± 7.3 Ma), which is correlated with a discrete pulse of Mid—Late Devonian plutonism recognised in the Karamea Batholith. The undated Mount Graham Granite (new) is also likely to be Paleozoic, based on chemical and petrographic characteristics. The bulk of the batholith (seven plutons) was emplaced in the mid Cretaceous (114–109 Ma) and comprises two related, yet distinct, geochemical suites, ..