| The Habahe gold ore belt is the most important gold deposit producing area ofthe Altai region. On the basis of previous research and local geological background,we are able to discuss the source of metallogenic matter, the fluid property,mineralization process, and so forth and enrich our understanding of the metallogenicregularity of gold deposits through contrast study of typical gold deposits in bothgeological characteristics and geochemical characteristics.The formation of Habahe gold ore belt has gone through several geodynamicstages such as trench-arc-basin system, collisional orogeny and post-collisionextension. The main mineralization period is the process from collision to extensionin accreting orogeny of convergent plate margin.The gold deposits of the belt have some shared characteristics. All of them areproduced in the Mar-kakol deep fault, closely related to the ductile shear zone,originated in the debris construction carbonatite-bearing of Devonian and closelyrelated to the Late Hercynian acidic intrusions. In the meanwhile, each gold deposithas retained distinct characteristics of its own. For example, the main metallogenesisof Duonalasyi gold deposit takes shape by albite granite porphyry dykes magmaactivities in the Middle Devonian, while that of Tuokuzibayi stems from extensionactivities in the early Permian epoch.The sandstone of Toksalei Formation, composed of high quartz maturitygreywacke, has developed in continental island arc environment. The Habahe rockmass, the combination of granite, granodiortie, diorite and monzonite diorite rock,possesses a feature of late stage fractional crystallization and strong acidic magma,and it belongs to I-type granites of metaluminous calc-alkaline crust-mantle mixedsource, which falls into volcanic arc granite area in tectonic setting diagram andreflects the geodynamic environment of subduction system.The ore-forming fluids of the main mineralization stage is medium-lowtemperature and medium-low salinity, formed in low-density and shallow depthenvironment. The study of H,O,S,Pb isotopes shown that: the evolution ofore-forming fluids originates from early magmatic water to the late meteoric; surfurcomes from deep magma, mixed with minor sedimentary sulfur; lead isotope comesfrom crust-mantle that relates to theorogenic, which takes shape in the process oforogeny by hydrothermal extract from its surrounding rock. Tungsten trace element,which is related to gold, can be used as the best indicator element of the gold ore belt.The Habahe gold ore belt, formed in the background of Hercynian Altai orogeny,has experienced such three stages as plate subduction to collision and then topost-collisional extension, causing large-scale tectonic movements and magmatism.The formation of deep faults and ductile shear zone can offer channel andmineralization storage space for meteotic water, magmatic water, and the subaqueousore-bearing hot brine. Due to the changes in the regional stress field that causes newtectonic activity, magmatic activity and diorite dikes, gold has been re-activated,migrated and thus largely enriched.Consequently, the typical deposits of the Habahe gold ore belt can be classified into orogenic, multi-phase, multi-stage, tectonic contact deposit through integratedresearch of multi Ore-controlling Factors. |
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