Geophysical exploration in the Xinglin Bay geothermal field, SE-China

Abstract

Xinglin Bay is a low-temperature geothermal field belonging to the Zhangzhou Basin geothermal area, one of the hottest geothermal areas in SE-China. In order to have a better understanding of the geothermal resource, MT and gravity data were processed and inverted and a joint interpretation with borehole data was carried out. Resistivity and density structures were studied and the surface heat flow was calculated. Geological structures were studied with geophysical work. Intrusive rocks show high resistivity and high density features. The borehole logs indicate that the regional temperature gradient is not as high as reported before. The occurrences of local natural springs are closely related to intrusions and faults. TEM work is recommended together with MT work to correct the static shift of MT data. Current geophysical work is not conclusive for geothermal exploration. Temperature gradient surveys are recommended before planning to drill deep boreholes.