| The Tayuan area is located in the northern section of Great Xing'an Range,and its tectonic position is Xingmeng orogenic belt.It belongs to Late Paleozoic and Mesozoic gold,silver,copper,molybdenum,lead and zinc metallogenic belt in the northern part of Great Xing'an Range metallogenic rovince(II grade),in Derbugan.The region has experienced the comprehensive influence of Paleo-Asian Ocean tectonic domain,Mongolia-Okhotsk tectonic domain and circum-Pacific tectonic domain.The tectonic background is complex,the metallogenic geological conditions are superior,and has higher research significance.Based on the theory of comprehensive information mineral prediction,this paper systematically collects the exploration and research results of the study area and the mining area.Copper,gold,lead and zinc are the main ore types,skarn and hydrothermal deposits are the main genetic types.On the basis of typical deposits,the metallogenic control factors and ore-controlling mechanism are determined,and the metallogenic model and comprehensive information prediction model are established.Through the comprehensive information interpretation of geophysical and geochemical data,the prospecting indicators and information are extracted,the prospecting potential of the study area is evaluated,the prospecting prediction area is delineated and the prospecting target area is optimized,so as to provide scientific basis for the subsequent mineral exploration work.Erzhixian lead-zinc deposit and Tayuan gold-silver-copper deposit have been found in the study area.Among them,the Erzhixian lead-zinc deposit is a small-sized skarn deposit.The orebody occurs in the skarn in the contact zone between the intermediate-acidic shallow intrusive body and the Xinyigenhe Formation,Jixianggou Formation and the nearby marble.The lead-zinc ore body is mainly accompanied by copper and molybdenum ore bodies.The magmatic rocks related to mineralization are Early Cretaceous granite porphyry,and NE and NW faults are the main ore-controlling structures.The LA-ICP-MS zircon U-Pb dating results of the Erzhixian quartz porphyry show that the diagenetic age is 136.5 ± 2.1 Ma.It is considered that the mineralization age of the Erzhixian lead-zinc deposit is Early Cretaceous,and the alteration closely related to mineralization is skarnization,silicification,epidotozatopm and pyritization.Tayuan gold-silver-copper deposit is a medium-low temperature volcanic hydrothermal deposit.Orebodies occur in quartz veins.Gold-silver orebodies are mainly associated with silver-copper orebodies.The magmatic rocks related to mineralization are plagioclase granite and plagioclase granite porphyry.Controlled by volcanic institutions,the metallogenic age is late Yanshanian.The altered mineral assemblages related to mineralization are sericitization,silicification and pyritization.Through polarization,extension and structural analysis of aeromagnetic data,the results show that the study area is mainly composed of NE-trending and NW-trending structures.The northeast and south are dominated by negative anomaly fields.Several small positive anomaly fields are scattered.The central,northern and southwestern are characterized by positive anomaly fields.The high-value positive field in the north roughly corresponds to the early Cretaceous – late Jurassic intrusive rocks in the mining area,and the high-value area below the north corresponds to the metallogenic geological body : the skarn contact zone of the Xinyigenhe Formation and the Jixianggou Formation and the rock mass of the subvolcanic facies.According to the statistical results of soil geochemical data,the variation coefficient and concentration coefficient of Au,Ag,As,Sb,Mo and Pb in the study area are high,and the metallogenic potential is good.Through systematic clustering and factor analysis,the metallogenic elements are divided into three combinations of Au-As-Sb,Cu-Zn-Cr-Ni and Ag-Pb-Mo-W-Bi,indicating that there is a feature of superposition and enrichment of multi-stage mineralization in the region.There are 102 single element anomalies in the region,including 35 anomalies of major metallogenic elements Au,Ag,Pb and Mo.Among them,Au-2,Ag-10,Pb-3 and Mo-2 anomalies have large scale,high anomaly intensity and obvious concentration center,and have good prospecting potential.There are seven composite anomalies delineated in the whole region,among which Ht-3 anomaly is composed of multiple elements and multiple anomalies,which has excellent prospecting significance and is the composite anomaly with the largest metallogenic potential in the study area.Based on the comprehensive information of geological,geophysical and geochemical prospecting indicators in the study area,the comprehensive information mineral prediction research is carried out,the comprehensive information mineral prediction model is established,and five metallogenic prediction areas are delineated,providing a scientific basis for the subsequent exploration work arrangement. |
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