Abstract
Abstract The Glenham Porphyry is a suite of andesitic terrestrial flows and subvolcanic intrusions in an inlier of Murihiku Supergroup sediments in eastern Southland. Potassium-argon dating has been used to determine the age of the volcanics. Plagioclase ages are in the range 182–240 Ma, indicating a probable Late Triassic to Early Jurassic time of extrusion. Discordant younger ages of whole-rock samples indicate argon loss from the glassy matrix, possibly caused by low-grade regional metamorphism during the Rangitata Orogeny.
Full Text 
Sign-in/Register to access full text options
Sign-in/Register to access full text options 
Published version (
Free)
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
