One Dimensional Resistivity Sounding for Resolving Gem-bearing Gravel Layer: A Comparison of Schlumberger with Wenner Techniques at Bo Rai, Eastern Thailand
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Abstract
A direct detection of gem-bearing gravel is very difficult in areas covered by basaltic layer, especially in the eastern Thailand gem field, since the resistivity contrast between the gravel and basalt layers is usually much greater than the resistivity contrast within the bedrock itself. Electrical resistivity surveys are considered to be the most effective method for resolving gem-bearing gravel overlain by basalt environment. Schlumberger and Wenner electrode array configurations were applied to resistivity sounding in order to compare their effectiveness in the eastern Thailand gem field. When compared with a known lithological section in the Bo Rai area, Thailand, both survey arrays in this study were able to detect a high resistivity layer of gem bearing gravel layer, which is located under the basalt. However, the Schlumberger array is clearly more suitable for detecting zones of local gem-bearing gravel layers being more efficient, faster and more economical than the Wenner array. Thus the Wenner array is considered an option only in terrains where Schlumberger sounding cannot be conducted due to a lack of open space.
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Copyright © 2008 Department of Geology, Faculty of Science, Chulalongkorn University. Parts of an article can be photocopied or reproduced without prior written permission from the author(s), but due acknowledgments should be stated or cited accordingly.
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