Abstract
Au distribution in biotite from intrusive and metamorphic rocks is discussed. Biotites have high Au contents relative to other rock-forming minerals: maximal mean contents occur for biotite in gabbroic rocks (14.5 X 10-7%), while minimal levels occur in granitic rocks (5.8 X 10-7%) in Palaeozoic folded regions. In all folded regions there are two distinct groups of granitic rocks: with low and elevated levels in the biotite, (0.7-1.9) X 10- 7% and (12.5-84.4) X 10-7%, respectively. The biotite of autometasomatically altered granitic rocks has Au content reduced by a factor of 1.5-6, while biotite from altered granites around ores has Au raised by a factor of 2-3 relative to the biotite in the initial rocks. Estimates are made of the mean Au contents in biotites from various types of intrusive rocks.-T.R.
Original language | English |
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Pages (from-to) | 138-154 |
Number of pages | 17 |
Journal | Geochemistry International |
Volume | 18 |
Issue number | 3 |
Publication status | Published - 1981 |
ASJC Scopus subject areas
- Geochemistry and Petrology
- Geophysics