Amphiboles and Biotite in Relation to the Stages of Metamorphism in Granogabbro

W. Smulikowski
Institute of Geological Sciences, Polish Academy of Sciences, Żwirki i Wigury 93, 02-089 Warszawa

Summary: The Bratteggdalen granogabbro, a relict mass in the Caledonian amphibolites of Vestspitsbergen, shows a series of amphibole development reflecting its thermal history. A brown Ti-rich hornblende occurs as a late magmatic mantling of pyroxene. Low-grade metamorphism (greenschist facies) was accompanied by the development of actinolite from pyroxene; subsequent amphibolite facies metamorphism saw the development of an alkali-rich, blue-green hornblende. The chemical changes in the amphiboles are a succinct illustration of those found in progressive regional metamorphism.

Mineralogical Magazine; December 1974 v. 39; no. 308; p. 857-866; DOI: 10.1180/minmag.1974.039.308.05
© 1974, The Mineralogical Society
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