Hydrogeochemistry as a tool for the assessment of aquifers in gaps of lithological well profiles

Published
2020-07-09
DOI: https://doi.org/10.14295/ras.v34i2.29764
Keywords: EPA Lagoa Santa Karst. Hydrogeochemistry. Karst Aquifers. Statistic. APA Carste de Lagoa Santa. Hidrogeoquímica. Aquíferos cárstico-fissurais. Estatística.

    Authors

  • Luisa Costa Martins Vieira Instituto de Geociências - Universidade Federal de Minas Gerais (UFMG)
  • Leila Nunes Menegasse Velasquez Instituto de Geociências - Universidade Federal de Minas Gerais (UFMG)
  • Ricardo Perobelli Borba Instituto de Geociências - Universidade Estadual de Campinas (Unicamp)

Abstract

The study area is located 30 km north of Belo Horizonte, and includes the entire Lagoa Santa Karst Environmental Protection Area and its surroundings. It represents an area of 505 km². The karst-fissure aquifer, developed in carbonated rocks of inferior (impure) and superior (pure) members of Sete Lagoas Formation – Pedro Leopoldo and Lagoa Santa respectively, is the most exploited. The other aquifers, which are comparably less explored, are the ones in metapelites of Serra de Santa Helena Formation, granites of Belo Horizonte Complex and granular overburden. Despite the large number of operating tube wells in this area, lithological description from rock loggings is precarious, which compromises their use in hydrogeological studies. In order to overcome this problem, hydrochemical results obtained and available lithological data were used. These are sourced from 21 sub-superficial and 85 deep circulation water samples. Piper and Stiff diagrams and statistical treatment of data, including Boxplots and Cluster analysis, were used in the study to classify groundwater according to its source. The classification proved to be effective, especially in the separation of silica and carbonate units. Further analysis can emphasize difference between both carbonated units.

How to Cite
Vieira, L. C. M., Velasquez, L. N. M., & Borba, R. P. (2020). Hydrogeochemistry as a tool for the assessment of aquifers in gaps of lithological well profiles. Águas Subterrâneas, 34(2), 204–220. https://doi.org/10.14295/ras.v34i2.29764