THERMALISM AND HYDROCHEMISTRY AS EVIDENCES OF REGIONAL

Published
2010-09-09
DOI: https://doi.org/10.14295/ras.v24i1.12982

    Authors

  • Arnoldo Giardin UNISINOS
  • Ubiratan Ferruccio Faccini PPGEO/UNISINOS

Abstract

Limits to regional flow in Guarani Aquifer System (GAS), produced by two lineaments, named Rio das Antas (RAL) and Rio Forqueta (RFL), had been identified in northeast Rio Grande do Sul State, Brazil. Thermometry and hydrochemistry were decisive criteria in flow barriers identification. The block of GAS located northeast from these lineaments presents hot waters (28,6 ºC to 46,7ºC) and hydrochemistry compatible with long residence time. To the south of RAL and west of RFL, waters are cold (19ºC 21ºC) and have chemical composition related to the exploited aquifer: Botucatu and Passo das Tropas, respectivelly. Potentiometric gradient can’t identify both flow barriers (RAL and RFL). To the south of RAL, hydraulic head distribution suggests existence of divergent flow, directed to Rio das Antas and Rio Caí valleys. RAL flow barrier is due to a horizontal heterogeneity (faulting); whereas the RFL one is vertical: Serra Geral and Santa Maria Formations being in direct contact. The limits defined by RAL and RFL for a cell flow in Guarani Aquifer System will eliminate discrepancies between modeled and observer hydraulic heads to the south of Rio das Antas valley.Key words: Guarani Aquifer, thermometry, hydrochemistry, lineament.

How to Cite
Giardin, A., & Faccini, U. F. (2010). THERMALISM AND HYDROCHEMISTRY AS EVIDENCES OF REGIONAL. Águas Subterrâneas, 24(1). https://doi.org/10.14295/ras.v24i1.12982