1. Federal University of Paraná, Laboratory for Research in Applied Geophysics, Department of Geology, Av. Cel. Francisco H. dos Santos, 100 — Jardim das Américas, P.O. Box 19045, Curitiba (PR) 81531-980, Brazil and Paraná State Secretary of Education, Av. Água Verde, 2140 — Vila Izabel, Curitiba — PR 80240-900, Brazil.(corresponding author).
2. Federal University of Paraná, Department of Mathematics, R. Evaristo F. Ferreira da Costa, 408 — Jardim das Américas, Curitiba — PR 81530-015, Brazil..
3. Federal University of Paraná, Laboratory for Research in Applied Geophysics, Department of Geology, Av. Cel. Francisco H. dos Santos, 100 — Jardim das Américas, P.O. Box 19045, Curitiba (PR) 81531-980, Brazil..