| Abstract |
Geological, geochemical and geophysical surveys were performed in the Dien Bien to develop the hydrothermal model associated with the Dien Bien hot springs. The geomorphology of the surveyed area is dominated by the Dien Bien Depression, which is a graben whose axis is oriented N-S. Four major geological structural features have been considered in the area: the Dien Bien deep-seated fault system, the Nam Rom deep seated fault, the NW-SE fault and NE-SW fault. All four faults cross the depression in which the Dien Bien deep seated fault system intersects the Dien Bien city centre. The integrated interpretation of the geological, geochemical and geophysical data, suggests a meteoric origin for Dien Bien thermal waters, which infiltrate in the northwestern zone of Dien Bien Depression or further areas, percolate at great depth and ascend at the Dien Bien Depression, probably due to the intersection of the existing fault systems. In fact, in these four zones, low resistivity values were measured, which are associated with the hydrothermal fluid circulation. |