The late crystallization stages of low-Ti, low-Fe tholeiitic magmas: Insights from evolved Antarctic and Tasmanian rocks
Leone Melluso, Janet Margaret Hergt, Alberto Zanetti
Lithos | ELSEVIER | Published : 2014
Examples of the latest stages of crystallization in evolved tholeiitic rocks can be found in the low-Ti, low-P Ferrar Magmatic Province in Antarctica (e.g., Thern Promontory and Archambault Ridge) and Tasmania (e.g., the Red Hill intrusion and Mount Wellington sill). Evolved rocks of this magmatic province include: a) rocks of basaltic andesite composition containing plagioclase, augite, pigeonite, and interstitial Fe-Ti oxides; b) rocks of andesitic composition with plagioclase as a liquidus phase, a single Fe-rich subcalcic clinopyroxene and Fe-Ti oxides; and c) rocks of dacitic composition displaying granophyric texture, containing sodic plagioclase, alkali feldspar, ferrohedenbergite, fa..View full abstract
We thank Giovanni Orsi for sampling the Them Promontory and Archambault Ridge sections and for useful advice, Pietro Brotzu for continuous scientific and personal support over the years, to Carlo Garbarino, Marcello Serracino and, particularly, Roberto de' Gennaro for their skilled help in obtaining microprobe data through the years and their limitless patience. We also thank Graham Hutchinson, Alan Greig and Jon Woodhead for their assistance in acquiring some of the electron probe and laser ablation data for this study, and Sergio Bravi for his skilled job in preparing polished thin sections. This paper is our tribute to Enzo Michele Piccirillo, who took the lead in modern petrogenetic and geochemical studies of continental tholeiites. This research is funded with Fondi Ricerca Dipartimentale to L.M. The careful and constructive reviews of Tom Fleming, John Foden and Teal Riley, and the Editorial comments of Andrea Marzoli were deeply appreciated.