摘要
笔者曾对直流电法的视电阻率进行过低通滤波.笔者认为:从微观物质组份来讲,可以认为岩石组份差异不是突变的,而是渐变的,因此理论上,可以说电阻率应当是一种连续的变化.在电法理论上,视电阻率的表征可以用连续函数式,说明理论基础其性质是连续的.在实际工作中,我们的测量数据也可以认为是连续数据的离散点值.连续函数性质决定我们可以使用一些滤波方法对其进行滤波处理.我们是在工作中对电磁法工作测得的视电阻率进行了滤波处理.而且我们定义滤波后的剩余视电阻率为"相对视电阻率".我们认为,这种"相对视电阻率"反映的不是岩性的变化,而是蚀变的,或者是同一岩性内部微弱的组份变化.通过研究区相对视电阻率计算,将硅化的地质体区分出来,从而将含铁石英岩的界线清理出来.解决了在电阻率差异悬殊的背景下,硅化的弱小电性差异不能很好视别的问题.
Apparent resistivity data obtained from direct current electric methods were low-pass filtered.We think that the variation of rock components is not abrupt,but gradual.As a result,the electric resistivity should be altered continuously theoretically.In principle,the expression of apparent resistivity should be in the form of continuous function explaining the continuum property.In practice,the measured data might be considered as the discrete points of the continuous function.The properties of the continuous function enable us to filter data using some algorithms.The apparent resistivities from electromagnetic work were filtered.The residual resistivity after filter is defined as＂relative resistivity＂.We think that it reflects the rock alteration,weak component variation of the rock alternatively,not the lithology variation.By computing the apparent resistivity in the work area,siliconized geological bodies can be differentiated,where by ferrous quartzite can be picked out.Under the condition of high resistivity contrast,the problem that weak electric discrepancies of siliconization is hard to be differentiated was solved.
出处
《地球物理学进展》
CSCD
北大核心
2015年第6期2760-2765,共6页
Progress in Geophysics
基金
中国地质大调查项目<大兴安岭成矿带北段覆盖区立体勘查程序示范>(12120113090600)资助
关键词
视电阻率
相对视电阻率
剩余异常
蚀变
含铁石英岩
apparent resistivity
relative resistivity
residual anomalies
alteration
ferrous quartzite
