APLICAÇÃO DE ELETRORRESISTIVIDADE EM SEDIMENTOS PALEOZOICOS E MESOZOICOS DO ESTADO DE SÃO PAULO

Resumo

In the State of São Paulo, the water wells are mostly concentrated in rocks of the Paraná Basin. Therefore geophysical prospecting was employed to determine its applicability in solving geologic and ground-water problems. There was also the intention to verify: how a "geophysical stratigraphy" corresponds with the geologic stratigraphy; if there is a correlation between lateral variation of resistivity and water production in the Tubarão Group sediments. The conclusions are:
- it seems that it is possible to estimate, with regard to the resistivity of the rocks, the production of a well in the Tubarão Group;
- the Botucatu Sandstone, when saturated of water, has a resistivity of about 30 ohm' m. The position of the water level and the thickness of the Sandstone layer are easily determined;
- the thickness of the basalt is not difficult to determine. When there are more than one flow, a strong "eletrical anisotrophy" may occur;
- the saturated Bauru Sandstone has a resistivity of about 18 ohm' m its thickness and the position of the water level can be determined.