The orientations of intrusive rocks from a carbonatitic lamprophyre dike swarm and the history of emplacement relative to country-rock schist structures are compatible with intrusion into tension fractures and Riedel shears formed during initiation of the dextral wrench system of the Alpine fault. New U-Pb and Rb-Sr dates indicate a late Oligocene-early Miocene time of intrusion which, in turn, suggests a mid-Tertiary history for propagation of the Alpine fault plate boundary through South Island, New Zealand.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.