The Hunan Qianlishan - Furong Tin Qitianling Tanaka, Pyrite And Fluorite Standard Features Of Study

Located in the Qianlishan-Qitianling, Hunan, the Furong orefield is a super-largeSn-poly-metallic orefield found in China. The main type of the Furong tin mine is theendogenetic tin deposit, and the exogenetic tin deposit takes a small proportion.According to mineralization stages, the endogenetic tin deposit can be divided intotwo sub-varieties, the pneumato-hypothermal deposit and the hypo-mesothermaldeposit. At present, more than fifty different tin ore veins have already been found,including the structural alteration zone type, altered rock body type, skarn type,greisen type and porphyry type. Tin ore deposit of various types mainly distribute inBailashui ore zone, Maziping ore zone, Shanmenkou ore zone, Goutouling ore zone,and Taoxiwo ore zone etc.Based on the analysis of the geological background of the typical tin deposits,the regional geological conditions of mineralization, the formation mechanism and themodel of mineralization, the paper applies the new theories and methods ofminerageny and prospecting mineralogy, uses the modern testing technology, to studythe typomorphic characteristics of fluorite and pyrite from some tin deposits inFurong tin orefield. The study gets important information about the formation of thetin deposits.The paper studies the pyrite's crystal form, chemical composition, S isotope andpyroelectric characteristics. The study shows that most of the pyrites are poor in S andrich in Fe, and they have the formation characteristics of magmatic hydrothermal. Thecomposition of S isotope in pyrites is similar with that of δ34S in granite, which showsthat S comes from the related igneous rocks. The pyroelectricity measured from pyriteshows that pyroelectric coefficients are all positive and belong to a hole-type (P-type)electric conduction. Also the pyroelectric coefficient is positively correlated with thecontent of Fe and is negatively correlated with the content of S in pyrites.The shapes, unit cell parameters, chemical composition, naturalthermoluminescence (NTL), and the inclusion of the fluorite from Furong tin orefieldare studied, and its genetic and prospecting typomorphic characteristics are analyzedin this paper. The result of NTL shows that the formation of fluorite is closely relatedto magmatic hydrothermal. With the REE becoming lower, the temperature of thethermoluminescence is higher and the curve of the NTL is more complex. Theinvestigation on fluorite inclusions shows that fluorite formed in the medium-lowtemperature, low salinity and low density environment. Because fluorite mainlyformed in the middle-late mineralization stage, it is considered that middle- andlow-temperature hydrothermal fluids played an important role in the latemineralization stage.In general, the paper studies the chemical composition, physical characters andtemperature of the mineralization from the mineralogical angle, and attains the newinformation about genetic and prospecting typomorphic characteristics which are veryimportant to analyze the formation of Furong tin orefield and help find the new tin oredeposits.