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Gahnite in the ∼3.75 Ga Isua Greens tone Belt, West Greenland

Published online by Cambridge University Press:  25 June 2018

P. W. U. Appel
P. W. U. Appel*
Affiliation:
Geological Survey of Denmark and Greenland, Copenhagen, Denmark
*
*E-mail: [email protected]
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Abstract

The Zn-spinel gahnite has been discovered in the ∼3.75 Ga Isua Greenstone Belt, West Greenland. It is light blue-green to colourless in hand specimen and colourless in thin section as opposed to most other gahnites which are dark green to brown. The gahnites from Isua have very low Fe and Mg contents, and their compositions are thus close to the endmember gahnite. The gahnite was formed, during metamorphism, from sphalerite, in the absence of Fe-rich sulphides.

Keywords

gahniteIsua Greenstone BeltGreenland
Type
Research Article
Information
Mineralogical Magazine , Volume 64 , Issue 1 , February 2000 , pp. 121 - 124
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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