رخساره هاي كانه دار، سيالات درگير و خاستگاه كانسار فلورين (روي ، سرب ، باريم ) ميلاكوه - تويه در سازند كربناتي سلطانيه ، البرز مركزي ، جنوب باختري دامغان

Ore facies , fluid inclusions, and genesis of Milakuh -Touyeh F(Zn-Pb-Ba) deposit, Lower Cambrian carbonate-hosted (Soltanieh Formation) in Central Alborz, Southwest Damghan, Iran

Milakuh-Touyeh the F-Zn-Pb-Ba deposit is located 45 km SW of Damghan. The country rocks of the deposit are dolostones of the upper part of Soltanieh Formation. The orebodies in the dolostones are located in certain ore-bearing facies as four ore horizons. The ore facies from bottom to top of the sequence are as follows: Dolosparite-sparstone is the facies of ore horizon I, in which Zn (Pb-F-Cu-Ba) mineral are the main paragenesis . Zinc is the major constituent of the horizon (economic ore horizon). Dolomicrosparite-dolosparite is the main facies in the ore horizons II and III, with F-Pb (Ba-Cu) paragenesis. Fluorite in horizon II is economic and mineable. Presence of altered tuff breccia facies with fluorite is the characteristic of the horizon HI. Laminated dolosparite, dark gray chert and ferrigenous dolomicrite are the facies of horizon IV. The main paragenesis here is F-Pb. The increase in silica content is an important characteristic of this horizon. Depositional enviromnent of ore-bearing and other facies in the upper part of Soltanieh Formation in the Milakuh-Touyeh area is tidal flat. The ore geometry, textures, structures and paragenetic sequence, indicate that the ore minerals are formed and concentrated in four stages: I-Deposition; 2- Early diagenesis; 3- Late diagenesis; 4- Uplift and exposure. Final stage of ore formation comes from remobilization of sedimentary-diagenetic generations and their epigenetic deposition in the open spaces, faults and fractures together with weathering and supergene enrichment. The majority of mining activities in the area have been concentrated on the late diagenetic and epigenetic types. Fluid inclusion studies on diagenetic types of fluorite indicate relatively high Th (211 ± 5 °C) and salinities (23.45 ± 5 wt% NaCl equivalent). The Th values for the epigenetic fluorite (fault species) are lower than those of diagenetic ones (134 ± 5 °C). Geometry of ore bodies, occurrence of ore horizons in certain sedimentary facies, ore texture and structures, depositional environment (tidal flat), paragenetic sequence of minerals and fluid inclusion data, all suggest that Milakuh-Touyeh F-Zn-Pb-Ba deposit is an F-rich MVT deposit.