Journal of the Geological Society; October 1990; v. 147; no. 5;
p. 739-742; DOI: 10.1144/gsjgs.147.5.0739
© 1990 Geological Society of London
Rapakivi granites, South Greenland: hydrothermal alteration of igneous layering
ADRIAN A. FINCH1,
R. JOHN REAVY2,
TIM N. HARRISON3 and
PETER E. BROWN4
1 Grant Institute of Geology, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JW, UK
2 Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, UK
3 Department of Geology & Petroleum Geology, University of Aberdeen, Marischal College, Aberdeen, AB9 IAS, UK
4 Department of Geography and Geology, University of St Andrews North Haugh, StAndrews, Fife, KY16 9ST, UK
Igneous layering is developed in the Proterozoic rapakivi granite suite of South Greenland in an area on the south-easternmost coast of the island of Angnikitsoq. The layering at this locality is unusual in that it is defined by interstitial phases. We suggest that large-scale hydrothermal alteration has converted a fine-grained pyroxene cumulate, in which original cumulate pyroxenes occurred in the interstices between larger feldspars, to interstitial biotite and green amphibole.
Copyright © 2009 by Geological Society of London