Research Of Metallogenesis And Prognosis In Tianmashan Sulfur-gold Deposit And Its Neighbor Areas, Tongling

According to the theory and method of ore forming system and polygenetic compound mineralization, this thesis tries to investigate geology and geochemistry, ore-controlling structural system, tectono-geochemistry, and remote sensing geology so as to establish the mineralizing model and find out prefered targets for Tianmashan sulphur-gold deposit and the neighboar area, with the resulths as follows:(1)The LANDSAT-7ETM's remote sensing data are used to extract the information of the argillization, ferrugination and mixture alteration anomaly in the 1500 km2 area in Tongling. Eleven prospecting areas were outlined based on the distribution characteristics' alteration and minerogenetic conditions.(2)It is shown, from field survey, that the features of cleavages in the host roucs are similar in Tianmashan and Huangshilao deposit. Charaterised by good development of the transverse joints with strike 295-320°. The distribution stress field of ore-controlling fault system, obtained from 2 sets of conjugate shear joints in the ore-hosted rocles in Tianmashan:σ1(Maximum major pressure stress):290°∠70°;σ2(intermediate principal stress): 130°∠20°;σ3(Minimum major pressure stress):38°∠7°.Because of this pressure stress, the main ore structures of Tianmashan deposit is strike-slip tensile normal faults, indicating the feature of the Tianmashan's tectonism feature during Yanshan Period.(3)The sulfur isotope of the ores is rich in S34 in Tongling ore concentration area. There are some relation between the genesis of sulfur and those for general sea waters as well as the thermal recovery of gypsum-bearing sulfur in stratum. All of these indicate the presense of terrestrial hot water sedimentation. The Pb isotope of samples are distributed along the the boundaries of upper crustal and orogenic fields showing that the source of Pb is related to the orogenic belt's environment, and part of Pb coming from supracrust participates in this process. The analyses of isotopic characteristics of H and O display that the metallogenic fluid has the characteristic of mixed liquid, and the meteoric water, groundwater, metamorphic water involved obviously.(4)The Cu and Au mineralizing in Tianmashan and its neighbor area shows the characteristic, of layer-control, variability and multi-generation. The metallogenesis has experienced submarine hot water deposition in Carboniferous and magmatic-hydrother deposition in the period of Yanshan. The metallogenetic key that the induction of early orebody and the large-scale circulation of metallic elements as well as S, C in thermal fluid system.(5)The methods of spatial analysis and information statistics, are used to build a forecasting model of mineralizing with information of digital deposit space for Tianmashan and its neighbor area. According to the calculating results of predicting unit and analysis of geology,14 targets areas are proposed.(6)Based on the spatial distribution of tectono-geochemical anomalies in testing zone of Tianmashan and Huangshilao and multivariate statistical analysis, it is suggested that the best mineralizing indicator element combination is Au-Ag-As for gold near the orebody in testing zone,the best mineralizing indicator element combination is Sb-Hg for gold beside the orebody and its neighbor area, and that the best mineralizing indicator element combination is Cu-Mo-Bi for copper near the orebody in testing zone. According to the information mentioned above and analysis of geology,5 areas targets in the testing zone air localised.