Wan D.,Jilin University |
Li J.,Jilin University |
Wang Y.,Jilin University |
Wang K.,Jilin University |
And 2 more authors.
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2014
Hongling lead-zinc polymetallic deposit share many similarities with others from the southern Daxinganling polymetallic metallogenic belt. There are two types of molybdenum mineralization in the mining area, including porphyry and skarn. The former, displaying spot-disseminated feature, occurs in granite porphyry, whereas the latter, displaying film like feature, occurs in quartz. The metallogenic age of Hongling deposit can be constrained from Re-Os isotopic dating of the two kinds of molybdenite. Five samples of spot-disseminated molybdenite yield model ages varying from 139.9±2.3 Ma to 141.5±3.2 Ma, with an isochron age of 140.3±3.4 Ma (MSWD=0.082), and a weighted average of 140.10±1.80 Ma. The isochron age and weighted average model age are consistent with one another, implying that molybdenum mineralization in Hongling deposit occurred in Late Jurassic. A film-like molybdenite sample yielded a model age of 143.7±3.6 Ma, representing the initial stage of lead-zinc mineralization. The Re-187Os contents of the film-like molybdenite are higher than that of spot-disseminated molybdeniteby one order of magnitude, which hints that they have different origins and there are two phases of molybdenum mineralization. The characteristics of Re content of the 6 molybdenite samples suggest that the ore-forming elements had a shallow source, and was mainly derived from the crust. The extremely low content of Re might be du to the low Re content within its parent magma as well as its paragenetic mineral assemblage. Combined with the results of previous study, it is concluded that (a) both rock- and ore-forming materials of Hongling deposit came from hyperplasia crust; and (b) the deposit formed in a dynamical environment of continental crust extension post Mongolia-Okhotsk collisional orogeny.
Li J.,Jilin University |
Wang K.,Jilin University |
Lu J.,Chifeng Hongling Nonferrous Metal Mining Co. |
Zhang X.,Jilin University |
And 3 more authors.
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2015
Hongling lead-zinc deposit is one of the representative large deposits in southeastern Inner Mongolia. Presently, there's very little research on geochemical characteristics and evolution of ore-form fluids, and ore genesis. The fluid inclusions are systemly researched in this paper, The results show that there are three types of primary fluid inclusions in garnet of garnet-skarn stage (I) including halite-bearing three-phase, aqueous two-phase as well as vapor-rich two-phase; there are two types of primary fluid inclusions in quartz of stage (II) including aqueous two-phase as well as vapor-rich two-phase. It is found in our microthermometric study that the ore-forming fluid is of high temperature, high salinity and immiscible NaCl-H2O type solutions and the boiling process plays important role in the precipitation of Pb, Zn, and Cu. Quartz of mineralization stage III to IV of quartz-sulfide epochs contains only aqueous two-phase of fluid inclusions. The homogenization temperature of this type of fluid inclusions is obviously lower than that of skarn epoch, while the salinity does not obviously change. The homogenization temperatures of fluid inclusions show a rising trend with salinities displaying a dropping trend of stage IV, and it may be caused by adding of high temperature, low salinity type fluid. The dropping of homogenization temperatures and salinities of ore-forming fluids from mineralization stages V to VI suggests that meteoric water continuously joining into the ore-forming fluid. Overall, the ore-forming fluids of quartz-sulfide epoch is of medium-low temperature and low salinity NaCl-H2O type solutions. C, H, O isotope study of fluid inclusions shows that the ore-forming fluids of skarn epoch mainly came from magmatic water and that of quartz-sulfide epoch came from mixed magmatic water and meteoric water, whereas at the latest stage of mineralization, the ore-forming fluids mainly came from meteoric water. The study of S, Pb isotopes implies that the ore-forming materials posed a deep source feature. ©, 2015, China University of Geosciences. All right reserved.
Song J.-Z.,Chifeng Hongling Nonferrous Metal Mining Co. |
Li J.-F.,Jilin University |
Wei L.-M.,Chifeng Hongling Nonferrous Metal Mining Co. |
Zhang X.-B.,Jilin University |
Wang K.-Y.,Jilin University
Northwestern Geology | Year: 2014
Pengboshan area belongs to eastern Beishan metallogenic belt, and located in the west of Ejina area, Inner Mongoulia. The Carboniferous Lvtiaoshan and Baishan Formation are primary ore layers, the type of gold mineralization is quartz vein, whose production is controlled by fault structures. Induced polarization intermediate gradien survey was carried out in No. 1 and No. 2 testing area, and many large-scale high resistivity anomaly belts have been detected, which indicates the existence of concealed quartz veins. Apparent resistivity of 600 to 1200ft. m is the geophysical prospecting symbol for finding those concealed quartz veins. Most of the anomaly belts don't have obvious abnormal apparent chargeability, thus the anomaly is reflected as barren or weak mineralized quartz vein. However, high apparent polarization is found in No. 1 testing area, with the characteristic of high resistivity and high polarizability. Therefore, we predict that the concealed quartz vein may contain considerable metal sulfides, and could have preferable potential in further prospecting work.