The Zhaoyuan-Pingdu fault is one of the three super large ore-controlling faults (Shanshandao,Jiaojia and Zhaoyuan-Pingdu) in the Jiaodong gold concentration area. Due to the coverage of Quaternary,the relationship between the spatial distribution of gold ores and the exposure of main and secondary faults has been still unsolved. This work conducted fine processing of regional gravity and aeromagnetic data in this area,such as upward continuation at different altitudes in spatial domain (100 m,200 m,and 500 m) and first vertical derivative. Results indicate that there is a displacement difference between the exposure of the Zhaoyuan-Pingdu fault and the deep geophysical gradient zone,and the displacement difference becomes significant along the southeast direction of the fault trend. It is further proved that the deep Zhaoyuan-Pingdu fault strikes southeast,and the dip angle gradually decreases from shallow to deep,with drastic local changes. High-precision surface gravity survey at a scale of 1/10000 shows that the gravity anomaly curves show a rapid upward trend from west to east,with local depression areas. The density of granitic and sericitized granitic rocks (2.63 g/cm3) is inferred to be between that of Linglong monzogranite (2.57 g/cm3) and Paleoproterozoic (2.82 g/cm3). There is a significant density difference between the ore-bearing layer and the surrounding rock. The gold deposit mainly occurs in the dip angle of granitic and sericitized granitic rocks,which changes from steep to gentle or from gentle to steep,and quartz vein type and altered rock type gold deposits can be discovered in this area.
关键词
地球物理/2.5维反演/布格重力异常/剩余重力异常/控矿构造识别/招远-平度断裂/胶东金矿集区
Key words
geophysics/2.5 dimensional inversion/Bouguer gravity anomaly/residual gravity anomaly/identification of ore-controlling faults/Zhaoyuan-Pingdu fault/Jiaodong gold concentration area
维普
万方数据