ROCK CAPACITANCE-THE NATURE OF INDUCED POLARIZATION IN GEOPHYSICAL PROSPECTING: A Discussion on the Phenomenon of Primary and Secondary Voltage
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摘要:
利用岩石、地质体的电容特性论证“激发激化”（IP）一次和二次电压的形成机理，指出了假说状态的IP理论错误，使得一次和二次电压现象能够科学地应用到地球物理勘探.根据实际的电阻都具有电容的特性以及实际的电容都“漏电”的事实，推定同样是电阻的岩石、地质体具有电容特性.利用岩石、地质体的电阻电容等效电路验证了岩石、地质体充放电过程中产生一次电压和二次电压，且一次和二次电压的和等于充电稳定时的电压的事实；在交流充电中，利用该等效电路同样验证了电流与电压间的相位移及阻抗的减小现象，并得到实测数据证明；利用实测数据，通过综合分析方法推断出等效电路推导的一次和二次电压与实测相符.岩石、地质体具有电容特性，实际上是体现了岩石具有电容这一物性特征.研究结果显示，一次二次电压的形成不存在“激发”因素，IP理论中的“极化率”大小与极化没有关系.研究表明，一次和二次电压的关系可以反映岩石、地质体内金属矿物的含量；利用岩石、地质体的充放电的时间常数、电容特性进行物探，对于识别隐伏地质体，效果会更好.
Abstract:With discussion on the formation mechanism of primary and secondary voltages in induced polarization (IP) exploration on the basis of capacitance property of rock and geological body, this paper points out the improper adoptation of the hypothetical IP theory, thus the phenomenon of primary and secondary voltage should be scientifically applied in geophysical prospecting. According to the fact that all actual resistors have the capacitance characteristics and all capacitors leak electricity, it is presumed that rocks and geological bodies as resistors also have capacitance. The equivalent circuit of resistance and capacitance in rocks and geological bodies verify that the primary and secondary voltage could be incurred in charge and discharge process, and the sum of two voltages is equal to the voltage when charging is stable. It also certifies that there is phase shift between current and voltage and decreasing impedance with increasing frequency in alternating current charging. Based on the measured data, it is inferred with comprehensive analysis that equivalent circuit-derived primary and secondary voltages are consistent with the actual measurement. The results show that there is no inducing factor in the formation of primary and secondary voltages, and the polarizability in IP theory has nothing to do with polarization. The relation between primary and secondary voltages can reflect the metallic mineral content in rocks and geological bodies, and the time constant of charging and discharging and capacitance characteristics can be effectively used in geophysical prospecting to identify hidden geological bodies.
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Key words:
- capacitance /
- resistance /
- equivalent circuit /
- geophysical prospecting /
- IP /
- primary voltage /
- secondary voltage
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[1] 刘国兴.电法勘探原理与方法[M].北京:地质出版社, 2005.
[2] 程志平.电法勘探教程[M].北京:冶金工业出版社, 2007.
[3] Pelton W H, Ward S H, Hallof P G, et al. Mineral discrimination and removal of inductive coupling with multifrequency IP[J]. Geophysics, 1978, 43(3):588-609. doi: 10.1190/1.1440839
[4] 邱关源.电路[M].第5版.北京:高等教育出版社, 2006.
[5] 傅良魁.电法勘探教程[M].北京:地质出版社, 1983.
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