| Abstract |
The structure of the Tokaanu geothermal field has been investigated using audiomagnetotelluricand magnetotelluric soundings. An initial interpretation of the electrical structure has been obtained from 1-dimensional modelling of the invariant apparent resistivity and phase at each measurement site. The spatial extent of low resistivities at depth is in excellent agreement with the location of observed surface thermal features. To the northeast of Tokaanu Thermal Reserve the boundary of the field is probably located close to the Tongariro River. To the southeast it appears that there is a very sharp,near vertical, boundary which is approximatelycoincident with a southwest-northeasttrending fault. |