| Tectonics of mining area is located in Ganzi-Litang southern tectonic zone.Tectonic zone, extending over eight hundred kilometers, is a complicated geologicalstructural unit, which runs through tectonic zone of the Western Sichuan plateau. Itstretches from the northwest, in other words, from Yushuzhiduo County of Qinghaiprovince to Sichuan province, and in the southeast, it passes through Dengke,Manigange, Ganzi, Tangli, Mula to Muli of Kangding County. The stratum of gold-mining zone in the Suoluo Ravine is a part of Bayankela stratigraphic zone, exactlyspeaking, that of Muli unit of Neiyidun—Zhongdian subarea in Bayankelastratigraphic zone. In the stratigraphic zone, the stratum uncovering mainly consists ofthe Ordovician, the Silurian, the Devonian, the Carboniferous, and the Triassic.The stratum with rich ore, situating in Gold-mining zone of the Suoluo Ravinein Muli, is distributed the middle of T3q2－1and the middle of T3q1－5, which iscontrolled by F1fault. Gold mineralization is produced in the rock combination ofbasic volcanic tosca, basic volcanic tuff breccia, which is typical of carbonation,siliconization, and cataclastion.There are eight ore bodies in the mining zone of the Suoluo Ravine, and No.10and No.15are the cores of the mining zone. Magmatic rocks in the mining zone aredivided into three kinds, that is, basic volcanic rock, diabase and lamprophyre. Thelamprophyre penetrates and slices the diabase and basic volcanic rock, with thefeature of later period. The structure of ore is composed of volcanic remains, remainsof porphyritic texture, and granular crystalloblastic fabric. There are more than tenkinds of constituents in the gold ore, including pyrite, arsenopyrite as the primary, andthe second is copper mineral, and natural gold is rare with granularity being less than0.1mm.The main vein minerals are sericite, dolomite, and quartz, followed by albite,secondary amphibole, chlorite, etc. According to analyzing geologic characteristics ofmineral deposit and mineral texture, the studying zone can be classified into theperiod of post-magma and Structure-hydrothermal alteration of mineralization andtable mineralization growing period,with different features of mineral association. Inthe mining zone, hydrothermal acts frequently along with fault zone, there are manytypes of alteration. The alteration related to gold mineralization includes silicification,pyritization, arsenopyrite, limonite, sericite, carbonation,etc. Compared with rock chemical composition of basic volcanic mineral in themining zone, altered rock mainly contains deterioration of SiO2, and incerase ofAl2O3、MgO、CaO、K2O、Na2O. In trace elements, the mine mafic rocks in the Ag,Mo, Sn are above1-3times of the basic rock Vickers value, and Cr, Co, Ba aresimilar, while Mn, Sr. are lower than the value of the Vickers1to3times. Theanalysis of rare earth shows that the number of the diabase in mining zone is REEΣREE9080.9-9710.4, LREE6490.1-7020.4HREE2220.2-2300.3, LREE/HREE ratioof boundary at20.9-30.1,（La/Yb） N11-120.5, the δEu value of00.2. Hydrogen andoxygen isotopes dD water-d18O water in the maps, display the nature of goldmineralization in the Suoluo Ravine is the solution to the precipitation, and mixedwith metamorphic water. The lead isotope Pb isotopic composition reflects obvioussimilarity and consistency of that in the mining zone. From sulfur isotope d34S value,it can be seen that the distribution of the Suoluo Ravine gold deposit d34S value isbetween typical hot brine side of the secretion deposits in the Carlin type golddeposits and igneous, metamorphic, and is more close to the general range of igneous,which may show a sulfur source is relative to magmatic activity.According to the above geological and geochemical characteristics, gold mineralin Suoluo Ravine of Muli is a part of shallow epithermal gold deposit. |
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