New heat flow density data from southern Portugal: a geothermal anomaly revisited

Previous geothermal work has indicated that a geothermal anomaly with heat flow density values in excess of 200 mW/m(2) exists in southern Portugal. Other geological and geophysical data from the area show no evidence of such an anomaly. To determine whether or not a geothermal anomaly occurs there, the published geothermal data and some new temperature data obtained from newly available wells, as well as from some of the previously used wells were reprocessed. The reprocessing of the published data took into consideration thermal and hydrodynamic equilibrium criteria, and so some of the wells that were previously used to draw the heat flow density map were rejected. Reprocessing of the data, together with the new measurements, indicate that a geothermal anomaly does not exist in the area and that it is a normal geothermal area with heat flow density values ranging from 50 to 90 mW/m(2). These values are similar to those obtained for other Hercynian regions in Europe. (C) 1998 Elsevier Science B.V. All rights reserved.