---

Rock unites which are exposed in Tak-I mine area are: Taknar formation (Ordovician), Mid-late Paleozoic and younger intrusive rocks. Taknar formation consists of sericite schist, chlorite schist, chlorite-sericite schist and some meta-diabase- gabbro-diorite. Taknar Polymetal (Cu-Zn-Au-Ag-Pb) Massive sulfide deposit formed at certain horizon of Taknar formation. Three style of mineralization are: stockwork, layered and massive. Due to strong tectonic activity in the area, dimension and geometry of deposit are being changed. Paragenetic minerals within the massive and layered are: magnetite + pyrite + chalcopyrite ± sphalerite ± galena ± sulphosalt ± gold + chlorite ± carbonate ± sericite. Magnetite is the main mineral in the massive zone. Paragenesis within stockwork are: pyrite + chalcopyrite ± magnetite + chlorite + quartz + sericite ± carbonate. Based on mineral paragenesis, the ore bearing solution had the following condition:
T ≥ 270 ºC, pH= 5 - 7, Log f O₂ = (-29) to (-30). Also, The range of chemical composition of some elements within Tak-I massive sulfide is as follow:

Cu = %0.01 - %5.86, Zn = 269 – 15600 (ppm), Pb = 27 – 4400 (ppm),

Au = 0.86 - 7.53 (ppm), Ag = 2.4 - 95.1 (ppm), Bi = 34 – 2200 (ppm).

Based on the paragenesis, alteration, style of mineralization, petrography, geochemistry, and structure, Tak-I is part of massive sulfide deposit. Due to high content of Cu, Zn, Au, Ag and Pb, Taknar massive sulfide deposit is a polymetal deposit. Based on high magnetite within sulfides and lack of pyrrhotite, Taknar is a special massive sulfide deposit.

---

Barika gold mineralization occurred in a Cretaceous metavolcano-sedimentary sequence at northwestern Sanandaj-Sirjan zone. Gold-rich volcanogenic massive sulfide mineralization occurred in a rhyolite to rhyolitic tuff unit which is completely in Barika shear zone. Based on electron microprobe studies, gold is observed to form electrum mostly, and in lattice of other minerals, such as pyrite, galena, tetrahedrite- tenantite, bournonite- boulangerite, twinte- vinnite. The main effect of deformation on the gold mineralization is migration of submicroscopic gold to cracks and crystal defects in minerals to form electrum under low to moderate strain and release of electrum from fractured mineral under higher strain. This behavior of gold can increase recovery of gold in Au-bearing ore deposits (Huston et al., 1992).    

---

Chlorite group minerals have a wide range of chemical compositions which reflect the physicochemical conditions of their crystallization. The solid solution (cationic substitution) model in crystal lattice of chlorite were satisfactorily used in estimation of its formation temperature in different geologic environments such as ore deposits, low-degree metamorphism, hydrothermal alteration and diagenesis by some researchers. In present research, the chlorite geothermometry method was used in the estimation of temperature of hydrothermal alteration and massive sulfide mineralization in the Qezildash area, northwest of Khoy city. In this work, at first, petrographic and mineralogical (XRD) studies were carried out on the samples taken from surface and borehole drilling cores. Eleven chlorite crystal grains which belong to different parts of hydrothermal system were selected and analyzed by electron microprobe equipment. Structural formulate were calculated on the basis of 14 oxygens. Chlorites have significant compositional variations and atomic solid solutions which reflect their formation temperatures. Chlorites from different parts of orebody and unmineralized altered rocks gave temperatures of formation of 318 to 368°C, and 202-210°C respectively. High-temperature chlorites have smaller Si contents than chlorites formed at low- temperatures.

---

The Cheshmeh Zagh area is located on Khorasan Razavi Province, the southern parts of the Sabzevar zone, which is one of the most important metallogeny zones of Iran. Lithologically, the area includes a variety of Late Cretaceous volcanic rocks (dacite to basalt), intrusions (gabbro to synogranite), Oligo-Miocene sedimentary rocks, and Quaternary sediments. Alteration zones of propylitic, chloritization, and epidotization well developed but the main mineralization zones can be seen in the form of two lens-shaped zones which are surrounded by argillic and silicification-sericitization alterations. Hypogene minerals include pyrite, chalcopyrite, and magnetite; while secondary minerals contain malachite, covellite, and iron oxides. The maximum content of the main elements in the main mineralization zones includes 1.5% Cu, 2230 ppb Au, 40 ppm Mo, 363 ppm Pb, and 738 ppm of Zn. Factors, such as the tectonic setting of the Sabzevar zone, the presence of a large number of Cu-Mn and deposits in relation to the submarine volcanic activities in the region, and the accompanying mineralization with dacitic volcanic rocks containing specific alterations in the Cheshmeh Zagh area, all indicate a probablity of the Bimodal Felsic-type (Kuroko) volcanic massive sulfide origin for these deposits. The Sabzevar structural zone has a great potential for exploration of this type of deposit, which should be taken into consideration.

---

Barika volcanogenic massive sulfide deposit is located about 18 km east of Sardasht in the northwestern Sanandaj–Sirjan metamorphic zone. The rocks in the Barika deposit predominantly consist of Cretaceous volcano-sedimentary sequences of phyllite, slate, andesite and tuffite, metamorphosed under greenschist facies grade. Barika deposit the only known example of gold-rich volcanogenic massive sulfide deposit in Iran. Ore mineral assemblages of the stratiform ore are quite various and consist of pyrite, sphalerite, galena, stibnite, electrum and a variety of complex composition sulfosalt minerals. Barikaite, Ferdowsiite and Arsenquatrandoriteare silver rich sulfosalt minerals that identified in the Barika deposit, has not been reported anywhere else in the world. Mineral structure of Guettardite has also been identified based on Barika deposit samples. The Barika deposit is a suitable location for mineralogical and crystallographic researches due to its rare and trace sulfosalt minerals.

---

The Sebandoon Barite (gold-silver) deposit is located about 20 km NW of the Kashmar in the Central Iran. The rock units exposed in the area consist of Eocene volcano-sedimentary sequences of lithic tuff, rhyolitic tuff, tuffaceouce shale, lapilli tuff and agglomerate associated with pyroxene andesite and trachyandesite. The barite is composed of lenticular, banded and stockwork mineralization and that is hosted in rhyolithic tuff. Lenticular, massive and banded barite contains pyrite, sphalerite,chalcopyrite, galena, tetrahedrite, argentite and electrum. The association of sulphide minerals with the barite indicates sub-oxic conditions during ore forming processes. In this study, the chemistry of sulfide minerals in the barite lenses was studied using Electron Microscope. Accordingly, the narrow range and low iron content within the sphalerite are similar to those of mineralization in a sub-oxic environments. The presence of elements with heavy atomic nuclei, such as gold and silver, in the pyrite indicates that the pyrites are formed in a sub-oxic environment and arsenic in the pyrite is replaced by metal (As^{3 +}). The presence of large amounts of antimony, bismuth, arsenic, and silver in the sulfide and sulfosalt minerals of this deposit indicates that the ore forming fluid was rich in the metal elements.

---

 The Sargaz volcanogenic massive sulfide deposit is located in southeastern Iran, northwest of Jiroft County. The lithology of the area includes pillow basalts, andesites, pyroclastics, and flysch. The formation of block smokers in basaltic units with pillow formation has caused the mineralization of copper and zinc massive sulfides in the Sargaz deposit. The copper and zinc mineralization event in the Sargaz deposit is in the southeastern part of the Sanandaj-Sirjan structural zone, which has been formed in the form of massive and stringers. Pyrite is the main sulfide mineral in this deposit, with chalcopyrite, sphalerite, tennantite, and pyrrhotite minerals seen with it. Siliceous and chlorite alteration in the mineralization zones is one of the most important alterations observed in the host rock of mineralization. These alterations are temporally and spatially dependent on the mineralization zone. Using the average homogenization temperature of the fluid inclusions obtained from 89 fluid inclusion samples, the separation of the sulfur isotope of the fluid from the sulfur isotope in equilibrium with sulfide minerals was performed. The studies showed that the origin of the sulfur in the mineralizing hydrothermal fluid consists of metamorphic rocks, as well as magmatic sulfur. The study of trace and rare earth elements in the mineralizing zone indicates a negative anomaly in HFSE elements and a positive anomaly in LILE lithophile elements. The positive anomaly in lithophile elements can indicate the mixing of the ore-forming fluid with silicate rocks.