Study On The Ore-controlling Structure Of Yanglin'ao Scheelite Deposit In East Hengyang, Hunan Province

Yanglin'ao scheelite deposit is located at superposed site between the SN-trending Leiyang-Linwu fracture and NE-trending Liuyang-Hengyang fracture,on the west limb of SN-trending Chuankou uplift between Hengyang diwa and Youxian diwa of the Jiangxi-Guili diwa system in southeast geodepressional region.It is a typical post-magmatic,hypothermal-mesotherm and filled-metasomatic tungstite deposit.Based on predecessor's work,the author gathered geologic information,made field investigation,sampled rock or ore specimens and did some analysis.With the help of the theory and method concerning modern petrology,study of ore deposit,geochemistry,mineralogy, isotope geology and metallogenetic prognosis etc.and the the knowledge of data processing,graphical simulation on computer,the author also analyzed the relationship among the ore-forming and stratum,structure and magmatic rock,especially gave emphasis to the time-space relationship between ore-forming and structure in minefield tectonic evolution history.What's more,not only metallogenetic rules were concluded,but also a new metallogenetic model and a new ore-controlling model were brought forward in the paper on the basis of the studies on geological features of ore deposit.All of these achivements could constitute the theoretical basis for the structural ore-controlling forcast.Yanglinao scheelite deposit was controlled by structural factors including Chuankou Uplift,contact belt,F₂₄Fracture,NNW-striking fissure zone and unconformity surface between Wuqiangxi Group slate and Yanglinao Group sandstone.These structures were combined into the metallotectonics system and were considered as ore-leading passage-way and accumulation space for ore-forming fluid,both F₂₄Fracture and unconformity surface were the essential migration pathways of ore solution,yet the NNW striking structural fissures were the important host structure.Hydrothermal fluid riched in metallogenetic elemen from Chuankou granite migrated along the granitic mass contact belt,F₂₄ Fracture and unconformity surface,filled into the NNE striking fissure, and then caused the enrichment and mineralization in the mine area under the metasomatism with wall rocks.