Research And Application Of CSAMT In Dahongshan Iron And Copper Mine Exploration

The typical Dahongshan Iron ore deposit copper mine geophysical methods of experiment and demonstration, by summing up the iron copper polymetallic ore deposit geology and geophysics for prospecting and effective method and technique combination, build up the typical ore deposit prospecting model, for the exploration of deep and hidden iron copper polymetallic deposit provides technique support. Paper adopt controlled source audio magnetotelluric method(Controlled Source Audio-frequency Magnetotelluric, CSAMT) as the main method, studying Dahongshan iron copper and peripheral deep electrical characteristics, combined with the results of the interpretation of gravity and magnetic exploration, to understand and analyze the ore controlling structure in the deep part of the study area from the perspective of geophysical.Paper is based on the deep technical problems encountered in the exploration of mineral resources, and foreign CSAMT progress in mineral exploration, electromagnetic field theory, outlined a two-dimensional forward and inverse theory of CSAMT; According to the geological and geophysical characteristics of mining conditions, paper establish the electrical structure model differences in the characteristics of deposits in resistivity by CSAMT dimensional forward modeling, to analyze the effectiveness and feasibility of the method in deep mineral exploration. Finally, thesis measured CSAMT data inversion two profiles were interpreted in accordance with the electrical and structural characteristics of inversion interpretation, combined with the physical properties of the test results and gravity and magnetic exploration results and geological data, geophysical characteristics of the study area and the deep structure. It features a comprehensive analysis.The density, magnetic susceptibility and resistivity of the rock and ore in the area of the red mountain iron and copper mine are analyzed according to the physical test results; we determined the differences of physical properties between the exploration targets and surrounding rocks. Through a comprehensive analysis of the inversion results of Dahongshan mine CSAMT profile, combined gravity and magnetic survey results, and based on looking for signs of mineral anomalies, we reached the following conclusions and understanding:(1) Copper Dahongshan stratigraphic features: Dahong deposits consist of a low-gravity, non-magnetic and low resistivity Triassic cover layer; Hongshanhill group has significantly higher gravity, high magnetic properties, the upper and lower part of the high resistivity low resistivity characteristics; Man'gang river group has significantly higher gravity, high magnetic properties, no seam of high resistivity and low resistivity characteristics of ore- bearing layer; Dahongshan syncline on the power structure showed significant "U" shaped feature, consistent with the characteristics of the substrate.(2) The structure characteristics of the Dahongshan copper miner: Dahongshan mine ore is mainly controlled by faults. Stratiform copper deposits are mainly distributed in the early formation of Hongshan group, southern F1 fault, deep covered by a small cap late reformation, basic rocks are not developed. There may be layered in rich copper fold configuration; From the view of basement features Dahongshan syncline, southern base controlled by F1 fault, after the substrate deepens steeply dipping outcropping. The main feature is the low resistance of carbonaceous clay schist potou group, gravity and magnetic anomaly distribution serials, reflecting the deterioration of the Hongshan group component, Man'gang river formation distributed continuously, without missing the old horizon. It is possible to infer that occur in layered copper layer extending due south. Gravity and magnetic electrical response characteristics indicate the scale of the intrusive rock there is no fault in the southeastern F1. Therefore, we infer that occurs in the group of rock the size of rich iron ore in the south of F1 fault, eastern north-south fracture are less likely to exist.