تشخیص نحوه رخداد و مراحل تشکیل معادن فلوریت پیناوند بر اساس دادههای زمین دماسنجی و عناصر نادر خاکی

Geochemical studies of the Pinavand Fluorite Mines indicates that fluorite has been deposited from a high salinity, typically low temperature and Mg-rich fluid in two stages: Based on geothermometrical data, at the first stage fluorites were formed at relatively high temperature (85-235Cº) and accompanied by host rock replacement (in the form of epigenetic dolomitization). The second stage of fluorite mineralization has occurred at low temperature (65-115 ºC) and has formed lodes and vein-likes along the breccia and fault zones. However, the salinity was relatively invariable (15- 23 wt% NaCl), suggesting salinity of fluorite-forming fluid was the same at all occurrences. By studying of REE patterns and regarding to some ratios of HREE to LREE, it could be observed that the first stage of fluorites was enriched in LREE revealing mineralization has occurred in early stage of crystallization .In contrast, the second stage of fluorites containing high proportion of HREE were deposited in the last stages of crystallization event. Based on the calculated (Yb/La), (Yb/Ca), (Tb/La) and (Tb/Ca) ratios, two mechanisms could be proposed: assimilation (replacement) for the first type fluorites and remobilization (rejuvinilization) for fluorites of the second stage.