Metallogenic Characteristics And Prediction Of Gold And Copper Polymetallic Deposits In Kalamaily, Eastern Junggar, Xinjiang

Kalamaily metallogenic belt in East Junggar is located between Altai mountains andTianshan mountains in the northeast part of Xinjiang. Belonging to the central part ofCentral Asian Orogen, it experienced a protracted and complicated tectonic development inPhanerozoic and produced numerous and distinctive types of structure, sediment andmagma, which provided favorable materials, dynamics and space for ore-forming process.As the important part of circum-Balkhash-Junggar Au-Cu polymetallic large metallogenicbelt, Kalamaily metallogenic belt can be well comparable to Kazakhstan and West Junggarareas in Central Asian Metallogenic domain in terms of regional metallogenic conditions,having good ore-prospecting potential.In recent years, masses of basic geological data related to geology, geochemistry andremote sensing have been accumulated, with the implementation and accomplishment of1:50000regional geological survey, National Project305, land and resource survey andprospecting potential area evaluation project, which builds up a better foundation for oreprospecting. However, this region still remains a low geological research level comparedwith the eastern developed regions. Some fundamental geological problems have not beenwell settled and researches on metallogenic regularity and prediction carried out by new oreprospecting theory and method are also insufficient relatively.On the basis of collecting, absorbing and referring to previous researches, the regionaltectonic evolution of East Junggar in Paleozoic have been further clarified by combinedmethods of field geological survey and geochemical analysis in this paper. Under theguidance of latest metallogenic theory and prediction, types of ore deposits in research areahave been determined, metallogenic series have been divided in detail and metallogenicregularities and ore-controlling factors have also been summarized. Furthermore,comprehensive information metallogenic prediction model has been established byextracting multiple geoscience information and prediction methods of the model have alsobeen optimized. Based on MAPGIS6.7and mineral resource prediction and evaluationexpert system（MORPAS3.0、GeoDas4.0）, a spatial location prediction research has beenperformed for mineral resources in this area. At last, prospecting targets are given andevaluated. The main achievements are listed as follows:1.According to the latest regional geological survey data and scientific researchachievements, bottom map of regional geology and mineral resource has been modified and improved in our research area and multiple geoscience spatial information database hasbeen established.2.Based on a comprehensive analysis involved stratum, structure and magma, it isinferred that:(1)the major part of the basement of Junggar Basin is mainly composedunderplated mantle-derived materials, subducted oceanic crust and island arc system.(2)Paleo-Asian Ocean in East Junnggar was not closed at the time of~320Ma and theinteraction of ocean-continent still existed. The volcanic and subvolcanic rocks from theCarboniferous Batamayineishan Formation was the product of back-arc extension inducedby the southward subduction of Paleo-Asian Ocean beneath Kazakhstan and Junggarplate.(3) Back-arc basin represented by Kalamaily ophiolites was not closed completely atthe time of~320Ma. The northern part of the Kalamaily structural belt was being subductedwhile the southern part was a uplift residual arc basin. Intensified continent-continentcollision did not occur in Kalamaily area. The closure of Paleo-Asian Ocean in this regionwas in the forms of continent-continent collage and the large-scale NW-SE trending dextralstrike-slip. Huangyangshan pluton may be the product under the strike-slip extension.(4)Middle-late Carboniferous magmatism in East Junngar has the distinctive features ofcrust-mantle hybrid and the mantle-derived materials accounts for a high proportion, whichmay lay better foundation for ore-forming process. Regional metallogenic conditions ofKalamaily metallogenic belt can be well comparable to Kazakhstan and West Junggar areasof Central Asian Metallogenic domain and have good ore-prospecting potential. TheKalamaily metallogenic belt has good ore-prospecting potential because of comparableregional metallogenic conditions to Kazakhstan and West Junggar areas in Central Asian.3.20geochemical elements have been processed and extracted to accomplishgeochemical anomaly maps and geochemical comprehensive anomaly maps by means ofcluster analysis, factor analysis and C-A multifractal method. In terms of geophysical dataprocessing method of Professor Wang Shichen, gravity and magnetic data have beenhandled to draw related maps and attributes of structures, rock boby and tectonic unit havebeen extracted. Meanwhile, combined with regional tectonic analysis,research area isdivided two different part tectonic unit by Kalamaily fracture, the north one and the southone.4. In the light of metallogenic series theory, the Au-Cu polymetallic ore deposits can bedivided two series, Au ore deposits related to early-middle Permian deformed andmetamorphic process of ductile shear zone and Cu-Mo(Au) deposits bearing a closerelationship with late Carboniferous intermediate volcanic and subvolcanic rocks, and metallogenic regularities and ore-controlling factors have been summarized.5.Based on GIS technology and by the means of a combination of qualitative andquantitative analytical methods, multiple metallogenic information of the two seriesmentioned above was extracted and comprehensive information ore prospecting model hasbeen established.6.Based on the hybrid model of data driven supplemented knowledge driven,thecombination method of prospecting-information contents and fuzzy weights of evidencemethod has been performed for Au ore deposits related to early-middle Permian deformedand metamorphic process of ductile shear zone,and9ore favorable prospecting target areaswere outlined,including2A type,3B type and4C type targets.7. Based on the hybrid model of knowledge driven supplemented data driven,thecomprehensive information prediction method has been performed for Cu-Mo(Au) oredeposits related to early late Carboniferous intermediate volcanic and subvolcanic rocks,and6ore favorable prospecting target areas were outlined,including2A type,1B type and3Ctype targets.