The Prediction On Prospecting Target Area Based On Regional Geochemical Data Analysis

Tongling-chizhou region geotectonic position is located in the northern edge of eastern part of the Yangtze plate, adjacented to Dabie orogenic belt and North China craton on the north side, connected to the Yangxin-Changzhou fracture on the south. Geological tectonic evolution has experienced the formation of the basement, cover layer deposition and intraplate deformation stages.The regional strata have the Sinian to Quaternary, lack of the Middle and Lower Devonian, and Lower Carboniferous, the sequence is complete. By the Indosinian and Yanshan intraplate deformation and extrusion effect, it developed EW, SN and NE trending fracture and NE trending fold. It has acidic granite class, such as diorite, quartz diorite, quartz monzonite porphyry, granodiorite porphyry and a small amount of rhyolite, controlled by the EW and NE trending faults. Development Cu, Au, Mo, Fe ore deposit which related with the Yanshan period acidic intrusive, the main ore-formation are Ordovician, Silurian, Middle and Upper Carboniferous, Middle and Lower Permian and Lower Triassic.The geochemical map compilation is based on the geochemistry of the original data, through the data preprocessing and GIS information extraction technology, statistics of geochemical parameters, using the above parameters, preparation of various geochemical maps and statistical analysis. On the study of copper polymetallic deposits’ geological background and regional geochemical characteristics in the Tongling area, establishing the geological-geochemical exploration model of Tongling copper polymetallic orefield. Summarization on the above-mentioned research results, forecast the target area and metallogenic prospect area in Chizhou area.Through the above geological and geochemical study, the understanding and conclusion:1. The average standard deviation of the traditional exploration geochemistry is the most appropriate to anomaly analysis in Tongling-chizhou region, abnormal display effect is most obvious, thus determine its as the calculation method of background values and abnormal limit.It also uses frequency method to statistical single element, used to produce the single element geochemical map, etc.2. The single element geochemical map shows that Cu, Au, Ag, Pb, Zn, W, Mo, Hg elements are mainly distributed in Shizishan, Xinqiao, Fenghuangshan, Shatanjiao orefield, and around Tongshan Town and Meijie Town, east area of the Qingyang County, etc.3. The single element geochemical anomalies map shows that the average standard deviation of abnormal limit can be a good method to show element enrichment center. Cu, Au, Mo, Pb, Zn ore-forming elements and associated elements anomaly center are mainly distributed around the typical orefields in Tongling area, the southwest and the southwest side of Tongshan Town, around Meijie Town, nearby Maya Town which between Chizhou City and Qingyang Country, the east area and the eastern region of the Qingyang County, etc.4. From the R-type cluster analysis result shows that due to the study of 1:200000 stream sediment data range is larger, with no or low anomaly area are too large, caused the overall clustering effect is not ideal, only Pb, Zn, Ag, etc associated elements have the better clustering results, Cu, Mo, Au,etc ore-forming elements clustering is not obvious.5. From the factor analysis result, F1 (Pb, Zn Cd, Ag, As) is associated with Pb-Zn mineralization factor, is an important copper polymetallic ore deposit associated elements; F2 (Na2O, K2O, Al2O3, Th, Nb) is related to the diagenetic factors, as the main rock forming elements; F3 (Sb, Bi, Au, Sn, Hg) is the factor related to gold mineralization, copper polymetallic deposit is another important set of associated elements; F4 (MgO, CaO, Fe2O3) is associated with the formation or iron ore deposit factor; F5 (Cu, Mo, W) is associated with the copper mineralization factor, reflects the regional elements combination of copper mineralization.6. From multiple element composite anomalies shows that ore deposits around the abnormal combination of ore-forming elements and associated elements nested relationship is good, can be further research in the deep and periphery. In some abnormal elements set, geological condition is good, but not found mineralized area should focus on the priority verification, such as the southwest of Tongshan Town, the east of Qingyang County, the west of Lingyang Town which located in the south of Qingyang County and other areas.7. From the denudation extent figure, Shizishan, Tongguanshan, Xinqiao, Fenghuangshan orefield erosion coefficient is less than 0.1, ore deposits (body) is not denudation, Shatanjiao orefield erosion coefficient is 0.54, ore deposits (body) is medium denudation, part of the ore body may have been destroyed. Shallow denudation element anomalies in orefield tend to be planar, have elements of zoning phenomenon; In deep denudation in the orefield, part of ore body have been denudation, the combination of main ore-forming elements and associated elements presents local anomalies.8. From GIS information extraction result, Tongling-chizhou region generally has high average of ore-forming elements and associated elements, among them, the Au, Pb, Ag, As, Sb, Cd elements’average is higher than the abnormal limit, these elements’anomaly area are more than 1500 km2, abnormal value contrast is also large.Typical orefield in Tongling ore concentration area anomaly magnitude higher element for orefield of main ore-forming elements and associated elements combination.9. From the similarity of the diagram, selected several typical orefields of typomorphic element composition and content of eigenvalue similarity comparison, the following areas exist great prospecting potential, southwest and the southwest side of Tongshan Town, around Meijie Town, the east of Qingyang County, special in the eastern region of Meijie Town, similar to the orefield of Shatanjiao reached more than 60%, very possible to find ore deposits (points).10. Studied deeply on Tongling ore concentration area, and in detail in the typical orefields in copper deposits on the basis of the geological background, metallogenic conditions, etc, combined with geochemical anomalies and the spatial distribution of regional characteristics, establish a typical copper polymetallic orefield geological-geochemical exploration model, used to guide to predict Chizhou region unknown prospecting target area and metallogenic prospect area.11. Through comprehensive study of regional geological background and the regional geochemical characteristics, the prospecting prospect is good and geochemical anomaly concentrated regions as metallogenic prospect areas. In the metallogenic prospect areas, according to geological and geochemical criteria to identify favorable metallogenic area, delineated prospecting target area, and divide the forecast level. According to different level, formulate the corresponding forecast verification work.