Mineralogical Characteristics and Metallogenic Significance of Ore-Bearing Quartz Veins in Baimiaogou Molybdenum Deposit, East Qinling Molybdenum Metallogenic Belt
DOI:
https://doi.org/10.54097/wzgpjn67Keywords:
Molybdenite, quartz veinlets, mineralogy, baimiaogou, east Qinling molybdenum metallogenic beltAbstract
The mineralogical analysis of ore-bearing quartz veins in molybdenum deposits is the basis for studying the formation mechanism of molybdenum deposits. This study takes the ore-bearing quartz veins of Baimiaogou molybdenum deposit in the world 's largest molybdenum metallogenic belt-East Qinling molybdenum metallogenic belt as the research object. On the basis of field geological survey and petrographic observation, combined with laser Raman spectroscopy in situ test, the mineral composition and fabric of ore-bearing quartz veins are analyzed, and their significance for mineralization is discussed. The results show that the ore-bearing quartz veinlets mainly occur in altered andesite. The main mineral composition is quartz, grade I gray to grade I yellow, with a content of about 90% and a particle size of 0.5mm ~ 60mm. There are residual potassium feldspar cleavage and scattered argillization materials inside, and a small amount of potassium feldspar with strong argillization between quartz minerals. It shows that quartz in quartz veins is secondary quartz, which is the product of strong silicification of felsic veins, and with the enhancement of silicification, the particle size of quartz minerals gradually increases. The ore-bearing quartz veinlet contains about 5% potassium feldspar, grade I ash, and remains between quartz particles with different degrees of silicification. In the same ore-bearing quartz vein composed of secondary quartzite, with the evolution from early to late silicification, sulfide mineralization has the characteristics of transforming from pyrite and chalcopyrite to molybdenite. Molybdenite is mainly euhedral-subhedral leaf-shaped, columnar, and agglomerated with good crystallization, and a small amount is semi-euhedral-allotriomorphic grain-like structure. It is mostly associated with pyrite and chalcopyrite. It is mainly developed in potassium feldspar, which is strongly residual after strong silicification, epidotization and chloritization in ore-bearing quartz veins, and is distributed in the contact area of early and late silica fossils.
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