庞西垌地区地球化学异常圈定方法讨论

Discussions on anomaly delineation method of geochemistry in Pangxidong area

庞西垌地区位于钦杭成矿带南段,是主要的贵金属、有色金属成矿区。区内构造复杂,岩浆活动频繁。基于庞西垌地区水系沉积物测量数据,以Au、Ag元素含量为例,分别利用传统统计学方法、趋势面法和分形方法计算其异常下限值,并圈定地球化学异常。通过对3种方法计算过程及应用效果的对比,分析了3种方法应用于本研究区的效果,进而揭示了复杂地质背景下,最适用于圈定地球化学异常的方法。

Pangxidong area was located in the south section of Qin-hang metallogenic belt and was the major metallogenic zones of precious metals and nonferrous metals. The tectonic structures were complicated and magma activity frequent. Based on the stream sediment survey data in Pangxidong area, the content of Au and Ag elements were taken as examples, their lower limit values were calculated and anomalies were delineated with conventional statistical method, trend surface analysis and fractal method. Through contrast of calculation course and application effect, the most appropriate method was explored for the delineation of geochemical anomaly under complicated geological settings.