The Main Mineral Typomorphic Characteristics of the Henan Tangjiaping Molybdenum District Using X-ray Diffraction and Rock Mineral Identification Technology

The Tangjiaping molybdenum deposit, discovered in 2006, is a large-scale porphyry molybdenum deposit. The studies of its basic geological work and metallogenic regularity have been completed by previous researchers with conventional geological methods. The results showed that the Tangjiaping molybdenum deposit belongs to the plutonic hypabyssal porphyry molybdenum deposit and the Tangjiaping granodiorite porphyry molybdenum mineralization acts as a mother rock mining area. However, there is no proof that the metallogenic regularity is from the perspective of mineralogy. From the mineralogy angle four kinds of typomorphic characteristics (chemical composition, trace elements, crystal structure, lattice parameters, structure etc.) of molybdenite, pyrite, quartz, and feldspar from the Tangjiaping molybdenum mine were studied using the separation of single mineral to chemical analysis, X-ray Diffraction and rock mineral identification technology. The results are: ① the mining area of molybdenite is 2H type, and the content of Re component is very low; the δ³⁴S of molybdenite values is 3.0‰; sulfur isotopic changes in a small range close to the meteorite sulfur with the characteristics of deep source sulfur, indicating that the sulphur is derived from the granite porphyry. ② pyrite is rich in trace elements Mo, Co, Cu, poor Ni, Pb, Zn, in addition, low content of Ag and Au, S/Se is greater than 250000, which is consistent with the 'S/Se more than 250000-500000 area could not find gold' conclusion. ③ quartz is rich in Mo. δ¹⁸O in mineralization quartz veins are lower, showing a small amount of precipitation appeared in the hydrothermal alteration during the later mineralization. ④ feldspar is rich in Mo. Light rare earth (La-Nd) content is higher than that of rare earth (Sm-Ho) content and heavy rare earth (Er-Y) content. Potassium feldspar degree of ordering, triclinic and structure parameter values were higher. Potassium feldspar structure at low temperature, shows that the potassium feldspar in this area is triclinic symmetry microcline at low temperature conditions, and it is the product of hydrothermal activity; rock potash feldspathization characteristics of molybdenum mineralization is the most favorable. The Tangjiaping molybdenum deposit therefore belongs to the plutonic hypabyssal porphyry molybdenum deposit, and this paper has important significance for the summarization of porphyry type molybdenum ore metallogenic regularity and prospecting marks.