Mineral Chemistry of Regional Chloritoid Assemblages in the Chlorite Zone, Lycian Nappes, South-West Turkey

J. R. Ashworth and M. M. Evirgen
Department of Geological Sciences, University of Aston in Birmingham, Gosta Green, Birmingham B4 7ET
Hidrojeoloji Mühendisliği Bölümü, Mühendislik Fakültesi, Hacettepe Üniversitesi, Beytepe Kampüsü, Ankara, Turkey

Abstract: In the Ören area at the base of the Lycian Nappes, chloritoid is common on a regional scale. Mn and inferred Fe3+ contents are low. Chloritoid + quartz occur rather than the more hydrous equivalent pyrophyllite + chlorite, Fe/(Fe + Mg) values in chlorite ranging down to 0·27. Calcite and dolomite, which coexist with chloritoid and pyrophyllite, give a temperature estimate of 350± 30°C, implying moderate to high activities of water for pyrophyllite stability. Muscovite-paragonite geothermometry is unreliable. Mg/Fe distribution coefficients between chloritoid and chlorite differ systematically from literature values from higher grades (biotite and garnet zones). Intensity of colour in chloritoid correlates with inferred Fe3+ content, which decreases outwards in grains showing prograde growth zoning.

Mineralogical Magazine; June 1984 v. 48; no. 347; p. 159-165; DOI: 10.1180/minmag.1984.048.347.01
© 1984, The Mineralogical Society
Mineralogical Society (www.minersoc.org)