نویسندگان
گروه زمینشناسی، دانشکده علوم، دانشگاه زنجان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The Qoushebolaq Pb-Zn occurrence, located 110 km northwest of Zanjan, is part of the Tarom-Hashtjin metallogenic belt. The mineralization occurred as a 200-meter long and 1-to-2-meters wide Pb-Zn-bearing quartz-sulfide vein (NE-SW/70-80NW) hosted by Eocene volcanic and volcaniclastic strata and is enclosed by 3-to-5-meters intermediate argillic alteration halos. Hydrothermal alteration in the study area comprises silicification, carbonate, intermediate argillic, and propylitic alteration. Pyrite, chalcopyrite, galena, sphalerite, pyrolusite, and psilomelane are ore minerals, and quartz, calcite, siderite, and sericite-illite are gangue minerals. Cerussite, smithsonite, malachite, covellite, and goethite are formed during supergene processes. The ore minerals formed as disseminated, vein-veinlets, brecciated, crustiform, colloform, cockade, bladed, plumose, vug infill, and replacement textures. Five mineralization stages can be distinguished at Qoushebolaq, where Pb-Zn mineralization occurred as quartz-pyrite-chalcopyrite-galena-sphalerite veins and breccias in the second stage. The Chondrite-normalized trace elements and REE patterns of ore samples, and host crystal tuff are comparable. This reveals that alteration and leaching of elements from the host volcanic and volcaniclastic are involved in mineralization. According to all the evidence, the mineralogical characteristics of the Qoushebolaq occurrence are similar to the intermediate-sulfidation type of epithermal deposits.
کلیدواژهها [English]
)