using Landsat imagery. This vegetation occurs predominantly in the central 
part of the nation and occupies an estimated area of 1,500,000 km, This 
mapping will provide valuable information for rational agricultural and 
cattle raising activities of this region, which is a priority of the 
present government. 
A project to control deforestation in the Amazon region was 
also in this program (SANTO 77). It has been made operational and trans 
ferred to SUDAM which is the government agency responsible for this 
control. 
Regional Geological Mapping 
The Brazilian regional geology is. generally not well known, 
even in large scales. In this respect, this program is of high importance 
since the knowledge of the regional geology is the first step for the 
systematic exploitation of the mineral resources of a region. To date, 
this program has already mapped the areas shown in figure 2, at scales 
equal or greater than 1:1,000,000 (MENES 77). 
Mineral Exploration 
Several projects have been completed in this program. Some 
of the more recent ones are: 
e Study of the circular structure that forms the alkaline massif of 
Pocos de Caldas, State of Minas Gerais, with Landsat imagery. This 
study allowed the definition of the main parameters that conditioned 
its radioactive mineralizations. It has been verified that the 
presence of radioactive minerals is related to secondary circular 
structures, internal to the main caldera (i.e. the known deposits 
are exactly in the perimeter of these internal structures). The 
mapping of these secondary structures, which were unknown before 
this work, is being used as a guide for further prospecting work 
in the area. 
e The mapping of the deposits of tin-bearing alkaline granites of 
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Marine