Pioneering insights into deep groundwater Comparison with subsurface flows

Abstract We present results of a pioneering study that provide new insights into the characteristics of deep groundwater flow systems of the Parana basin. The technique employed, based on geothermal methods, is capable of providing simultaneous estimates of both vertical and horizontal components of groundwater flows. The analysis use of bottom-hole temperature data from oil wellsVertical velocities of subsurface flows are the range of 10 -10 to 10 -9 m/s while the horcomponents are generally an order of magnitude higher, falling in the range of 10 -9 to 10 -8 m/s. obtained have allowed identification of three different regions of up flows and five different regions of down flows, at depths ranging from 1000 to 400geographic distribution of such flow patterncomplex interplays of subsurface recharge and discharge systems of groundwater in the Parana basin. This system is unlike that found in the basins in the Amazon region, where systematic lateral flows in the west –is ubiquitous. Introduction