نوع مقاله : مقاله پژوهشی
نویسندگان
گروه علوم زمین، دانشکده علوم طبیعی، دانشگاه تبریز، تبریز، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Molybdenum-copper deposit of Shele Boran is located about 2 km northeast of Ahar within the Ahar-Arasbaran metallogenic belt. This deposit is hosted by Eocene volcanic igneous rocks (tuff, agglomerate, andesite and dacite) and Oligocene intrusive igneous bodies (granite, granodiorite and diorite). These rocks host hypogene potassic, phyllic, propylitic, and argillic alteration zones where mineralization is often associated with the potassic and phyllic alteration zones. In these rocks, hypogene mineralization is predominant and occured mostly in the form of dissemination and vein-veinlet (chalcopyrite, molybdenite, pyrite and magnetite). This mineralization is covered by supergene accumulations such as hematite, goethite, malachite and azurite in the surface part of deposit. Four types of fluid inclusion in quartz crystals associated with mineralization were identified, including (1) two-phase fluid inclusion liquid-rich (L-V), (2) two phase fluid inclusion gas-rich (V-L), (3) three-phase liquid-gas-solid (L-V-S) and (4) vapor-rich monophase (V). The studied fluid inclusions have a homogenization temperature ranging from 123-447°C. The L-V-S three-phase fluid intermediates are homogenized by the disappearance of the NaCl crystal in the temperature of 156-317°C, corresponding to the salinities in the range of 30-40% by weight of NaCl. Two phase inclusions liquid-rich (L-V) intermediates show salinities in the range of 0.36-15.9% by weight equivalent of NaCl. Based on microthermometry data, boiling, mixing and simple cooling of mineralizing fluids are effective mechanisms in the formation and expansion of this deposit. The ores were most likely of magmatic and magmatic-meteoric origin. Alteration and mineralization of mineral accumulations, and microthermometric data confirm the classification of the Shele Boran deposit as a porphyry molybdenum-copper deposit.
کلیدواژهها [English]