Integrated Information Metallogenic Prediction Of Tin-polymetallic Deposit In Western Gejiu, Yunnan

Gejiu tin deposit which have abundant mineral resource contain Cu, Pb, Zn, W, Ag, Bi, In and so on is the most important tin-polymetallic deposit in the metallogenic district in southeast of Yunnan province. And it is also the important tin producing area in the world which the tin reaerves have the ten percent of the world. For the long time exploration of the Gejiu tin deposit, it's prove up reserves had already work out, many mines have the big problems that the shortage of the mineral reserves which is mostly factor to restrict the economic development of Gejiu. The area of Gejiu district which have disparted by Gejiu fault is 1700 km~2, and the area of western Gejiu district is 1100 km~2, the eastern Gejiu district is 600 km~2. The eastern Gejiu district have the super model tin-polymetallic deposit, and the western Gejiu district whict have the same geological conditions is the future target to expand the reserves of tin-polymetallic. So how to find valuable tin-polymetallic deposit in western Gejiu district is a big problem crying for solved recently.In this dissertation, the author integrate the regional geological background, deposit geological characteristic, geophysical characteristic, geochemical characteristic and remote sensing characteristic, based the integrated information exploring model, assessment mineral resources in Gejiu district by using characteristic analysis method, and filter the prediction target in the western Gejiu district. The mainly researches content and conclusion of the dissertation are that as following.1. Based the regional geological background, regional geophysical and regional geochemical characteristic, take the Douyan tin deposit as the representative deposit to summarize the metallogenic conditions, metallogenic rules and metallogenic symbol. It found that the relational mineralzation stratums are Triassic Gejiu group and Falang Group, the structure of western Gejiu district can be divided into "one arc, three zones", the metallogenic element present the four zone from the western magma rock to south of district that reflect the process of metallogenic from high temperature to low.2. By using the method of matching strain wave, current analysis and interspace extending to deal with the gravity and aeromagnetic data, it found that Douyan, Lihuazhai in western Gejiu district and Laochang, Kafang in eastern Gejiu district are approximately in the same gravity isoline, and aeromagnetic anomaly is in the center of Shenxianshui magma rock, most of mine are in the fiat aeromagnetic isoline.3. By using the "C-A" (concentration-area) multifractal method, the 20 geochemical elements of stream sediments have been studied in Gejiu area, Yunnan. The results show that the ore-forming elements including Sn, Cu, Pb, Zn, Ag, Au elements have the distribution with highly clustered continuous multifratal. These elements show great anomaly and good metallogenic potential. Analysis the geochemical element in western Gejiu district by using clustering factor analysis method, it found that the mostly anomaly distribute in the eastern Gejiu district, the anomaly in western Gejiu district distribute in the Douyan and Lihuazhai and mostly element anomaly are Sn, Pb, Zn.4. According to the false colour composite image of 7, 4 and 1 band of ETM and geological map in Gejiu district, it distinguished the line strcture and arc structure. The line structure could be reduce to four groups which is SN, NE, NE and EW direction, and the arc structure is the magma rock. By Using the Crosta method to distill the anomaly of Iron alteration in Gejiu district, it shows that the anomaly mostly distribute in the eastern Gejiu district and only a little in the shouth and north of western Gejiu district.5. Based the integrated information exploring model, assessment mineral resources in Gejiu district by using characteristic analysis method on MORPAS3.0, and filter the prediction target in the western Gejiu district. Finally three first prediction targets (A1, A2, A3) and three second prediction targets (B1, B2, B3) were delineated in the Gejiu district. The Lihuazhai prediction target (A2) has the same metallogenic conditions with Kafang, Laochang deposit, so it has better prospecting foreground. And the Douyan prediction target (A3) has the prospecting potential in the deep and periphery.