Mapping of Structures in Cenozoic Sediments With GPR in Para and Amazonas States, Brazil

Ground penetrating radar (GPR) has been tested at numerous sites in equatorial Brazil. In the Manaus region, Sauck, et.al. (1995a) showed that penetration to as much as 12-14 meters could be achieved with the 100MHz antennae at the six sites which were tested. In the Belem area, Sauck, et.al. (1995b), similarly demonstrated successful use of GPR at four sites representing different geologic and geomorphic environments. The method has had very little reported use in applications to structural mapping, but we show that conditions in Amazonia are generally excellent for deep GPR penetration (more than 15 m) and thus it can be very valuable to assist structural and stratigraphic mapping. The structural geologist is no longer limited to road cuts and outcrops, but can now extend subsurface mapping to areas of thin cover and also to greater depths below the mapped outcrop areas. We describe here the results of preliminary GPR profiling at four different sites in Amazonian Brazil.