Various talc occurrences, associated with metasedimentary series are found in Western Anatolia. In the studied area, the mineralogical and chemical features of Gümeli talc occurrences, which are derived from Triassic epimetamorphic series (metaclastics and metatuffs intercalations with phyllite and crystallized limestone) by hydrothermal alteration, have been determined. In addition, behaviour of major and trace elements were examined during formation of talc. According to the geological investigation, chemical and mineralogical studies three talc types were determined in Gümeli talc occurrences. Talc types are as follows; 1) Yellowish-gray ferrous talc, 2) Green, carbonate-bearing talc, 3) Green pure talc. Talcs were produced by the alteration of Mg-chlorites within the composition of epimetamorphic rocks and were formed ideal crystal structure. The talc occurrences characterized by the assemblages talc + chlorite + dolomite + magnesite + magnetite. Whole-rock chemical analyses of samples of talc, by comparison with epimetamorphic rocks, represent a net gain Si02, Mg0 and Cr203 and, a net loss of Al203, Fe203, Ca0, Na20, K20, Ti02, P205 and Mn0 during formation of talc. Similarly, lossing of Ba, Sr, Zr, Y and Nb and gaining of Ni and Co have been determined when we compared epimetamorphic rock with talcs. The amount of total REE’s (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) are the average of 11.295 ppm. In comparison with the normalized PAAS (Post-Archean Australian Shales) pattern, Gümeli talcs show a depletion in REE.
Subjects | Geological Sciences and Engineering (Other) |
---|---|
Journal Section | Research Articles |
Authors | |
Publication Date | June 30, 2004 |
Acceptance Date | January 1, 2004 |
Published in Issue | Year 2004 Volume: 17 Issue: 1 |