Research On Metallogenetic Geological Conditions And The Predicting Models Of Compound Information In East Tianshan Of Xinjiang

Paper theme: Research on Metallogenetic Geological Conditions and the Predicting Models of Compound Information in East Tianshan of Xinjiang Speciality: Geo-exploration and Information Technology Advisor: Professor Wang ShichengThe Eastern Tianshan Mountain Region of Xinjiang is an important metallogenic ore occurrence of non-ferrous, ferrous and noble metal where series of deposits have been found. The mineral characteristics of the region are more in ore occurrences, large in deposit scale, rich in mineral variety and easy in exploitation.The research region is located at the joint between Tarim and Junggar plates, including 5-second structure units such as the active margin belt of southern Junggar, the Kawabulak-Xingxingxia terrain, the active margin belt of nouthem Tarim and the paleo-landmass of Tarim, and 6 third structure units such as Dananhu and Haerlik island arc belts of paleaozoic era. The cropped geostromes consist of Archaeozoic, Proterozic Erathem and Sinian, Cambrian, Ordovician, Devonian, Carboniferous, Permian, Triassic System and so on, among of which Carboniferous System is distributed most widely. The region lasts long geological structure evolutionary process and the geological structures are very complicated. A serial intrusive rocks and large area volcanic rocks were formed by multi-magmatic activities from Archaeozoic, Palaeozonic to Mesozonic eras. The magmatic activities of Neopalaeozonic era are the most intense. The area of exposed intrusive rocks is about 20 percent of the total area of the region and the acidic rocks are 86 percent of all rocks.The regional gravitational and aeromagnetic anomalies in 1:200000 scale shows regional EW direction and high gravity value area with complicated changes, and EW direction, regional high-low magnetic strips with complicated changes.Statistic results from rock geochemistry measurement show that Cu, Au,As, Ag, Hg, Bi, Mo, Cr, Co and Ni are relatively concentrated and these elements and W are non-uniformly distributed. The results of stream or rock statistics geochemistry survey show that the high background and anomalies of Cu, Pb, Zn, Ag, Au etc are distributed in zonal or massive arrangement, and formed the anomaly concentration in some locations. Therefore, Cu, Au, Pb, Zn, Ag Ni and other relevant elements have conditions to the metallogenitic.32 types of minerals had been found such as iron, gold, copper, nickel, silver, lead, zinc, molybdenum, titanium, manganese, tungsten, and more than 60 metallic deposits have been explored, whose genetic types are related to porphyry copper deposit, liquational copper and nickel suphide deposit, volcanic gold deposit, sedimentary -reformation lead-zinc deposit, etc. The mineralizing processes are much complicate, and the ore geneses are multi original. The region is divided into 5 third-grade metallogenic belts such as Dananhu copper (molybdenum), gold metallogenic belt, and 14 fouth metallogenic sub-belts such as Xiaorequanzi copper, and gold sub-belt.Regional geological, gravity, magnetic and geochemical surveys of 1:200000 scale, and great deal of mineral exploration and geological researches had been made. It is an important research subjects about how deeply we research with the large number of geological, geophysical, geochemical data, and what we can extract for mineral information finding to predict mineral resources. At the same time, it is also an important foundation of assembling prospecting methods to pre-exploration of minerals that finding mineral works in different levels will be set up by carefully investigating known mineral fields, deposit-control conditions and genetic types of deposits.On the basis of investigated the mineral geological condition of Eastern Tianshan and guided by the ore-predicting theory and method system of compound information, the gravity and aero-magnetic data had been taken upward continuation in 2km, 5km, 10km, 20km, and horizontal first -order directional derivative of 0°>45o>90°, 135° and vertical second-order derivative of corresponding heights. Some aligned structures and annular structures are extracted based on the gravity and aeromagnetic data, and the interpretation maps of aligned, annular and basement structures are made.By Qualification theory, on the basis of evaluating the rational degree ofthe known ore-control factors, the ore-control factors had been analyzed. The results show that the Cu, Ni, Au, Pb, Zn, Ag deposits are controlled mainly by the aligned interpretation structure of SN and NE direction, secondarily by those of NW and EW direction; mainly by middle to the deep aligned structures (10-20km), secondarily by the shallow aligned structures(2-5km). The large or middle scale deposits are generally located in or nearby the intersection position of multi groups of aligned interpretation structures, mainly at the edge and seldom in the center of concealed interpretation basement; mainly at the pitch end or raising sides of concealed interpretation massifs or on the contact strip between the massif and adjoining rocks.By deeply researching the geological, geophysical, geochemical mineral formation conditions, the prospecting-ore effects of geophysical and geochemical methods from large down to middle scale, and the characters of some typical deposits, such as Tuwu porphyry copper deposit, Huangshan liquational copper and nickel sulphide deposit, Kanggu-er volcanic gold deposit, Shiyingtan volcanic hydrothermal solution gold deposit of continental facies and Weiquan skam silver polymetal deposit, the predicting models of compound information of these deposit fields, and the ore prospecting models of geological, geophysical and geochemical methods with cropped, shallow, middle to high buried depth deposits had been built. The results show that special geological circumstance, the intersecting area of aligned structures and annular structures interpreted by geophysical data, high background and local anomaly area of main ore-forming elements and interacting elements are probable ore-forming areas; the geochemical survey in 1:50000 scale has the active function of reducing the area of the anomaly district of 1:200000 regional geochemistry, and dividing further the prospecting area and commodities, and it can remedy a defect of weak control ability to local anomalies of 1:200000 geochemical survey because of arid and desert landscape, therefore it must be applied in prospecting. In the valuation of deposit, the geophysical methods play an important role in prospecting cropped and concealed ore-bodies. Among of these models, one is prospecting model of trinity "porphyry + malaquita (or copper anomaly) + high IP anomaly" to porphyry copper deposit; and another is three high and one low...