Analysis Of Gold Geochemical Characteristics And Metallogenic Prospect Of Balong Area In The Central East Kunlun,Qinghai Province

The study area is located in the iron,copper and gold polymetallic metallogenic belt of East Kunlun,which is characterized by complex geotectonics,well-developed strata,structures and magmatic rocks with good metallogenic geological conditions.Gold and polymetallic mineral resources are abundant,and prospecting prospects are favorable.Based on the project "1:25,000 geochemical survey in Balong area,Dulan County,Qinghai Province",which is supported by Qinghai Geological Exploration Fund,this paper reprocesses the geochemical exploration data on the basis of the study of Wulonggou fractured altered rock type gold deposit and Asiha gold deposit.The lower limit of element anomaly is determined by conventional method and content-area fractal method respectively,and the rationality of the lower limit of gold anomaly determined by the two methods is discussed.Based on the previous research results,the geochemical characteristics and anomalous characteristics of gold are analyzed,the prospecting potential of gold deposits is evaluated,and prospecting prospecting areas are delineated,which provides the basis for the follow-up prospecting work deployment.The main achievements and understandings of this paper are as follows:1.According to the content characteristics of gold in different tectonic units and geological bodies,we provide that Au element is mainly enriched in the northern Kunlunstratum and tectonic zoning,and Au element enrichment is related to the intrusion of Middle Triassic granodiorite.The enrichment and dispersion characteristics of Au elements show that the distribution of Au elements in Balong area is extremely uneven,and there is a precondition of enrichment and metallogenesis geochemistry.Combining with the results of anomaly verification in the later period,Au is one of the dominant minerals in this area.Au mineralization is associated with As,Sb and Ag low-temperature hydrothermal elements.According to the results of spatial distribution of Au,We determined that Au element and its metallogenic elements As,Sb,Ag associated are mainly concentrated in Nuomuhongguole,Yikeguole,South Hatu reservoir-Bulawan area,the middle reaches of Hatu and Erweiqigen area.Based on the structural,stratigraphic,rock distribution and characteristics of the study area,and the spatial distribution characteristics of 1:25,000 geochemical element assemblage anomalies,two gold geochemical zones are divided into Au-Sb-Mo-W-Bi-Li geochemical zoning of Wulasitai-Gaxiong and Au-Sb-Ag-La-Cr geochemical zoning of Tawenghada-Kekesaiyi.2.The abnormal lower limits of Au and related elements are determined by traditional method and content-area fractal method respectively.Because of the influence of super high value,the anomaly lower limit determined by traditional method is lower than that determined by content-area fractal method.The corresponding anomaly area of high value data of content-area fractal method is smaller,which has little influence on the calculation of anomaly lower limit results,so that the anomaly lower limit can be reasonably determined.By comparing the results of anomaly verification,it is reasonable and feasible to determine the lower limit of element anomaly by content-area fractal method,especially for Au and other hydrothermal multi-stage metallogenic elements.3.The geochemical anomaly zoning of the Wulasitai-Gaxiong in the northern part of the study area and Tawenghada-Kekesaiyi in the central part of study area are favorable areas for gold deposit formation.The ore-controlling effect of faults in the north-south and north-west directions is obvious.Especially,the intersection of faults in the north-west-west direction and faults in the north-south and north-east directions beside the faults is a favorable enrichment site for mineralization.4.The research results of Wulonggou and Asiha gold deposits show that the mineralization is closely related to regional faulting tectonics and magmatic hydrothermal action of acid rock mass of Indosinian granodiorite.The mineralization type is belong to tectonic altered rock type.5.According to the comprehensive study of geochemical anomaly distribution of gold elements,the geological characteristics of the area and the characteristics of typical deposits,five prospecting areas for gold mineralization have been delineated: Yikeguole ore prospecting area of gold(Grade I),South Hatu reservoir-Bulawan ore prospecting area of gold-lead-graphite(Grade I),Tawenghada-Nuomuhongnaren ore prospecting area of gold-antimony-chromium(Grade I),Naomuhun-Kekesaiyi ore prospecting area of gold-lead-silver-REE(Grade I)and Wulasitai-Nuomuhongguole ore prospecting area of gold-molybdenum-copper(Grade II).On the basis of prospecting evaluation,six gold prospecting targets are delineated according to the results of anomaly verification: Au prospecting target area of Yikeguole,Au-Pb prospecting target area of South Hatu reservoir,Au-Cu prospecting target area of West Tawenghada,W-Au prospecting target area of Kendeleng,Au-Pb-Ag-REE prospecting target area of the middle reaches of Hatu,Pb-Au-Cu prospecting target area of Dongtuotuonaren.It points out the direction for follow-up prospecting work.