岩溶塌陷自然电场及其应用
流经土洞或岩溶塌陷坑中的地下水破坏了土层的固-液界面离子双电层扩散区中正、负电荷的平衡,引起地下介质(土层)自然极化,形成自上而下的自然电场。土洞或岩溶塌陷在平面上产生自然电位似同心圆负心异常、在剖面上引起极小值异常;自然电位梯度在剖面上出现过零点异常,在平面上呈以零值线为对称轴的正负对称的似“蝴蝶状”异常。岩溶区自然电场法干扰因素主要有工业游散电流等人文干扰电磁场、地下金属管道(线)自然极化电场、上升或下降泉自然电场、山地电场、炭质灰岩自然电场等。针对岩溶区自然电场法干扰因素特点,本文提出采用避让法、排除法、在线监测法进行消除,并将之应用于广西来宾市吉利村岩溶塌陷探测中。结果表明,自然电位剖...
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Published in | 中国岩溶 Vol. 32; no. 4; pp. 480 - 486 |
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Main Author | |
Format | Journal Article |
Language | Chinese |
Published |
中国地质科学院岩溶地质研究所/国土资源部、广西壮族自治区岩溶动力学重点实验室,广西 桂林,541004
2013
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Subjects | |
Online Access | Get full text |
ISSN | 1001-4810 |
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Summary: | 流经土洞或岩溶塌陷坑中的地下水破坏了土层的固-液界面离子双电层扩散区中正、负电荷的平衡,引起地下介质(土层)自然极化,形成自上而下的自然电场。土洞或岩溶塌陷在平面上产生自然电位似同心圆负心异常、在剖面上引起极小值异常;自然电位梯度在剖面上出现过零点异常,在平面上呈以零值线为对称轴的正负对称的似“蝴蝶状”异常。岩溶区自然电场法干扰因素主要有工业游散电流等人文干扰电磁场、地下金属管道(线)自然极化电场、上升或下降泉自然电场、山地电场、炭质灰岩自然电场等。针对岩溶区自然电场法干扰因素特点,本文提出采用避让法、排除法、在线监测法进行消除,并将之应用于广西来宾市吉利村岩溶塌陷探测中。结果表明,自然电位剖面曲线在地面沉陷区中心附近出现极小值异常,自然电位梯度剖面曲线也在相同部位显示过零点异常。水文地质监测钻孔在相应的位置上分别揭露了塌陷堆积物、溶洞和断层破碎带,从而验证了上述自然电场法异常的属性。 |
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Bibliography: | CHEN Yi-xiang, GAN Fu-ping, LU Cheng-jie, WEI Ji-yi (Institute of Karst Geology, Chinese Academy of Geological Sciences / Karst Dynamics Laboratory, MLR ~ GZAR , Guilin, Guangxi 541004,China) 45-1157/P The groundwater that flowing through soil cave or karst collapse pit destroys the balance of posi-tive and negative charges in the ion double electrode layer between the solid-liquid interface in soil,which induces spontaneous polarization of underground medium (soil layer)and forms downward natural electric field.The soil cave and karst collapse cause self-potential negative anomaly that looks like concentric ring in the plane view and cause minimum value anomaly in the profile.The self-potential gradient appears zero crossing point anomaly in the profile and appears "butterfly-shaped" anomaly that is negative-positive sym-metrical in relation to the symmetry axis of zero value line in the plane.The main interference factors of nat-ural electric field in karst region are industrial stray currents,spont |
ISSN: | 1001-4810 |