Cladistic methods as a tool for terrane analysis: a New Zealand example

Abstract

ABSTRACTA cladistic analysis of New Zealand's basement terranes was conducted using 44 present/absent characters that were derived from the literature for a broad range of geological characters, including zircon age profiles, clastic source, metamorphic grade and igneous petrology. The analysis resulted in a classification showing that both the Eastern and Western provinces are natural groupings. Two monophyletic clades (natural historical groupings) were identified within the Eastern Province: a Central Arc clade of South Island terranes (Maitai/Dun Mountain, Murihiku and Brook Street), and the younger greywacke terranes plus the North Island Murihiku Terrane. The Rakaia and Kaweka terranes of the older Torlesse are basal to (less derived than) the Central Arc and Eastern Province younger greywacke terranes. Although cladistic methodologies have been developed for biological systems, these results demonstrate a proof of principle for their application to terrane analysis.