DATABASE FOR MINERAL EXPLORATION

Since the beginning of the 20th century Brazil, especially through its Geological Survey (CPRM), has significantly developed geoscientific databasefor the country. Geologic, geophysical, geochemical mappings and studies for the integration of these data had been carried through extensive portions of the national territory. This group of data, which is permanently being enlarged, covers great parts of areas with important mineral potential.

This database comprises geologic mapping in the scales of 1:1,000,000, 1:250,000 and 1:100,000, magnetometry, gamma-ray spectrometry and gravimetry geophysical airborne surveys and regional geochemistry surveys of stream, soil and rock sediment and pan concentrates.

Last decade geologic mappings in scales 1:250,000 and 1:100,000 were resumed. With the effort done in recent years, besides 100% of Brazil having been mapped at 1:1,000,000, we have 54.6% of the domestic territory covered with mapping in a 1:250,000 scale, areas covered with mapping in a 1:100,000 scale reach 13.9%, and the areas outside sedimentary basins are significantly covered.

From 1971 to 2001, 48 airborne geophysical projects in several regions of the country have been carried out, the majority of which are regional surveys with flight line spacing of 2,000m to 1,000m and flight height of 150m. An area of about 2,413,323Km² was covered in this period.

At the beginning of the years 2000, a new phase in the geophysical airborne survey was initiated, where all the magnetometry and gamma-ray spectrometry projects had been carried through with 500m spacing between the flight lines, at a flight height of 100m and N-S flight line direction. The results reached are significantly better that those obtained in the previous century. To this should be added new data processing and interpretation techniques.

During this period, an area of about 3,726,364km² was covered, what corresponds to 43.76% of the Brazilian territory and approximately 95% of the crystalline basement of Brazil. From 2004 to 2014, the investment for the acquisition of such airborne surveys corresponded the US$ 188 million dollar.

The programs of regional geochemical surveys were resumed by CPRM in 2009, with the accomplishment of wide geochemical prospection programs in areas of mineral interest, totalizing 351,055 samples recorded in the “Geoquímica” (Geochemistry) base.

Considering all the geochemical projects developed, Brazil has almost half of its territory covered with non-systematic geochemical sampling: about 4,135,479 km². Of this total, 3,738,957 km² are covered with sampling of active stream sediments (44% of the country); 3,121,999 km² with pan concentrates (36.7% of the territory); 1,813,499 km² with soil sampling (20.1%) and 1,620,370 km² (19% of the country) with rock sampling for geochemical purposes, in the period 1971-1995.

The current geoscientific database implemented by the Geologic Survey of Brazil (CPRM) is called GEOSGB (former GEOBANK) and is one of most comprehensive and effective of the world, oriented to graphical objects and contains several information bases.

GEOSGB is a relational database, developed in Oracle® platform. At the moment, it gathers outcrops, geochronological datings, structures, geodiversity, geochemistry, lithostratigraphy, projects, mineral resources, petrography bases. All data are consolidated and available for access through the Internet.

The geology, geochemistry and geophysics data are available for download directly through link:
http://geosgb.cprm.gov.br.