Studying the shallow crustal structure of the Qingchengzi ore filed in Liaodong by using seismic reflection profile
The Qingchengzi ore field is located in the central part of Liaodong region,and contains a large number of gold and Pb-Zn deposits.Although many studies of geology and mineral deposits of the ore field have been conducted,the ore-controlling structures and the shallow geological framework have been unclear yet,which hampers our understanding of the mineralization process and the future ore exploration.Based on the two-dimensional seismic profiles in the Qingchengzi ore field,this article conducts tomographic imaging research to obtain shallow geological structural characteristics of the crust above 9km depth beneath the ore field.Our imaging results show that:(1)the general upper crustal structure beneath the Qingchengzi ore field is characterized by a"double-layer"framework,meaning that the Paleoproterozoic metamorphic sedimentary rock series,the Liaohe Group,overlies the Archean basement,and that the Liaohe Group in the area can be divided into three stratigraphic sequences:upper,middle,and lower,with evident interfaces and a total thickness of 5000～6700 m;(2)the structural framework of the ore field is a thrust system rooted from the Jianshanzi reverse deep fault,which provides a reliable basis for analyzing the structural styles and mineralization of the Baiyun and Xiaotongjiapuzi gold deposits;the NW-trending Jianshanzi fault is a first-order fault in the Qingchengzi ore field,which likely acted as the conduit for the ore-forming fluids in the area,controlling the distribution of gold deposits in the eastern part of Qingchengzi;(3)a hidden intrusion was identified within the Dashiqiao Formation on the footwall of the Xiaotongjiapuzi fault,and it is speculated to form during the Indosinian-Yanshanian period and to be genetically related to the gold mineralization,suggesting that the deep part of the ore field has a high potential for gold mineralization.Based on these new results,a gold mineralization model was established for the area,which is helpful for determining the ore-looking for and exploration directions.
Migration imagingCrustal structureQingchengzi ore fieldGold depositMetallogenic model
万方数据
维普
