UnB - Instituto de Geociências - Produção Científica
RESUMOS/ABSTRACTS

Estimativa de densidades a partir de dados gravimétricos distribuídos aleatoriamente. 

Blum,M.L.B.

International Congress of the Brazilian Geophysical Society, 7th, 2001, Salvador, SBGf. Extended Abstracts.

Abstract

In a gravity survey, Bouguer and terrain corrections require the knowledge of subsurface densities. Commonly, rock samples taken from outcrops, boreholes or mines are left in laboratories for specific weight determinations. However, those results may not be representative of subsurface rocks. In spite of that, good estimations can be taken from gravity measurements in site as suggested by many authors. In this paper I present an improved method using the relation between free-air anomaly versus Bouguer and terrain corrections in randomly collected gravity data. The method was applied to a survey released in Crixás, Goiás, Brazil. The results show great correlations to laboratory measured densities and well-known geology: 3.2 to 3.4 g/cm3 for mafic/ultramafic rocks and 2.4 to 2.9 g/cm3 for gneissic rocks.