Open AccessChemická zonálnosť Ti-andraditového granátu v Ca-skarne z oblasti Magnetový vrch pri Tisovci (Slovenská republika)
Author(s) -
Peter Růžička,
Pavol Myšľan,
Martin Števko,
Sergii Kurylo
Publication year - 2021
Publication title -
bulletin mineralogie petrologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.239
H-Index - 10
eISSN - 2570-7345
pISSN - 2570-7337
DOI - 10.46861/bmp.29.049
Subject(s) - andradite , grossular , calcite , diopside , skarn , mineralogy , pleochroism , crystallography , geology , geochemistry , chemistry , crystal structure , metamorphic rock , fluid inclusions , quartz , paleontology
Analyzed garnets from the Magnet hill area near Tisovec (Slovak Republic) are part of a Ca-skarn mineral association consisting of diopside, clinochlore and calcite. Compositionally they correspond to Ti-rich andradite (Adr50.9-73.7) with minor grossular (Grs3.8-44.5) and schorlomite (Sch0.5-41.5) components. Garnets contain up to 13 wt. % TiO2 and in all of them YFe3+>YTi ratio prevails. Both sector and oscillatory chemical zoning were observed, which is primarily caused by variable distribution of Ti contents within individual garnet crystals. The three principal zones were distinguished in BSE imaging. The brightest are Ti-enriched zones with Ti content ranging from 0.85 to 0.50 apfu. Titanium gradually decreases in transitional zone (0.17 - 0.40 apfu) and reaches the minimum values in the dark zones (0.01 - 0.13 apfu). In the Ti-enriched zones the content of Si4+ and Al3+ is decreased due to substitution of Ti4+ and Fe3+ and assumed hydrogarnet substitution (SiO4)4- ↔ (O4H4)4-.