| Abstract |
The region of "El Ramal JujeÒo" in the eastern part of Jujuy Province, northwestern Argentina, presents several areas with thermal manifestations, mainly warm springs. Reconnaissance studies were able to delimit three locations with surface spring temperatures ranging between 37? and 58?C; they are: Aguas Calientes de Caimancito, Laguna La Quinta and Termas El Palmar. Detailed geological and geochemical surveys were carried out to evaluate their individual characteristics, as well as to develop a conceptual model of the area. The thermal system occurs in a Cretaceous-Recent sedimentary basin, more than 5 kilometers thick. A main structural system striking NNE characterizes the region, and is responsible for spring occurrences parallel to the western foothills of the Santa B·rbara range. Geochemical surveys showed that each location has its own water type, related to its circulation depth. Isotopic determinations indicate that thermal waters are of meteoric origin, with recharge occurring west of the areas of interest, where the permeable strata hosting the aquifers crop out. On the basis of chemical geothermometers, the water subsurface temperatures are estimated to range between 80? and 125?C, resulting from deep groundwater circulation under a normal geothermal gradient. As shown by old exploration oil wells, high temperatures might be found at shallower depths by drilling in the foothill areas of the western Santa B·rbara range. |