New geological and hydrogeological implications of the resistivity distribution inferred from audiomagnetotellurics over La Fournaise young shield volcano (Reunion Island)
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- 作者：Courteaud ; M. ; Ritz ; M. ; Robineau ; B. ; Join ; J.L. ; Coudray ; J.
- 关键词：La Fournaise volcano ; Audiomagnetotellurics ; Geoelectric structures ; Volcano-tectonic processes ; Groundwater ; Reunion Island
- 刊名：Journal of Hydrology
- 出版年：1997
- 出版时间：December 31, 1997
- 年：1997
- 卷：203
- 期：1-4
- 页码：93-100
- 全文大小：527 K
文摘
An audiomagnetotelluric survey has been performed along an inactive flank of La Fournaise volcano massif in Reunion island, to study the subsurface resistivity structure. One-dimensional modelling of the AMT data at each site revealed an extensive low-resistivity (less than 10 Ω m) zone at a few hundred meters below the surface. The significance of this unexpected conductive substratum is discussed in relation with the proposed impact of volcano-tectonic processes (caldera and landslides collapses), and a new interpretation of the geological structure is proposed. Moreover, it is likely that these conductors are poorly permeable argilaceous materials; then they coincide with a limit in permeability and determine groundwater behavior.