Estudo Geofísico Preliminar Com Os Métodos Tem/Fem Na Planície Costeira Norte Fluminense

In 1998, ON/CNPq and LENEP/UENF undertook a geophysical pilot study in the Northern Coastal Plain of Rio de Janeiro State, near Rio das Ostras town. The region is characterised by both the scarcity of drinking water for human consumption and the existence of saline intrusions; this last caused mainly by the presence of a complex quaternary geology and the excessive exploitation of the aquifers. The research was performed by employing the time (TEM) and frequency (FEM) domains electromagnetic methods to evaluate the effectiveness of both methods in these geological conditions in order to be able to formulate a more comprehensive hidrogeological research in the region in near future. The FEM profiles and the uni-dimensional interpretation of the TEM were able to depict the different geological formations, to locate the main aquifers and to reveal the salty water- fresh water contact. Our results evince a promising future for using eletromagnetic geophysical methods in the region as well as it confirmed that a regional survey is essential in the indication of most suitable places to locate productive fresh-water wells.