Geological,Geophysical And Geochemical Characteristics And Comprehensive Prospecting Model Of The Southern Ore Block In The Zhaishang Gold Deposit,Gansu Province

The Zhaishang gold deposit,one of the Carlin-Carlin-like gold deposits,located in the West Qinling Orogen,Gansu Province.Under the current prospecting situation,the traditional methods have been considered to be difficult to make progress,therefore,comprehensive prospecting methods are imperative.To guide the deep prospecting and exploration,we established a comprehensive prospecting model by using the modern exploration technologies,such as geology,geophysics,and geochemistry.In this paper,the southern ore block in the Zhaishang gold deposit is chosen as our research object.The main results obtained are as follows:(1)The ore bodies are mainly controlled by the NWW-trending faults and occurred in the contact between slate and limestone.The wallrock alterations consist of silicification,pyritization,arsenification,and limonization,which can be used as a direct criteria for prospecting.(2)The CSAMT is used to extract abnormal information.The electrical gradients(between H1 high-resistance and L2 low-resistance anomalies)correspond to the No.32 vein,indicating that a high possibility of ore existence in this electrical gradient zone.(3)The data is addressed by using the method of Grigorian.In 43 line of the southern ore block,the results show that the As-Mo-Sb-Ag-Cu-Bi-Au-Zn-W-Pb is the original halo sequence,with the front halo elements of Pb and Sb,the near mineral halo elements of Au,Ag,As,W,and the tail halo elements of Mo,Cu,Bi,Zn.The tail halo elements Mo and Bi are located at the front halo elements and the near mineral halo elements of the sequence.The near mineral halo element Pb is located at the position of the tail halo element of the sequence.These distributions indicate that the shallow ore bodies are most likely to be weathered,and there may have blind ore bodes in the depth.(4)Based on the characteristics of geophysics,geochemistry and geology,a comprehensive prospecting model is established in this paper.By drilling verification in the south ore block,orebodies occurs at the depths.