Banca de QUALIFICAÇÃO: JOÃO HENRIQUE OLIVEIRA DA SILVA

POTENTIAL OF THE USE OF AEROGEOPHYSICAL DATA IN GEOLOGICAL AND PEDOLOGICAL 

MAPPING IN A MOUNTAIN REGION OF DIFFICULT ACCESS

aerogeophysics, geological mapping, pedological mapping

The present study aims to evaluate the potential of using data

magnetometry and gamma-spectrometry aerogeophysics integrated in a GIS environment

with geological, pedological and topographic data to improve the detailing of the

thematic maps (soils, geology) currently available for the mountain region of

Rio de Janeiro state. Pedological and geological maps can serve as

support for various environmental surveys, mining, agriculture,

monitoring of risk areas, civil construction, among others in regions

mountainous and/or difficult to access, where there may be, for example, slopes

accentuated and dense vegetation cover. The integration of these data has character

promising, since the aerogeophysical data of magnetometry and

gamma spectrometry are still few used in environmental surveys. At the

present work it was possible to define lithological, structural and pedological domains,

determine the genetic character of rocks and soils and interpret the processes of

spatial distribution of sediments through radionuclide concentrations

K(%), eU(ppm) , eTh(ppm) and the ratios K/eTh, eU/eTh and K/eU associated with the

structural framework without the need to fund a team in the field, due to

problematic relief and vegetation that the study area, with all its proportion

territorial, presents. The survey of aerogeophysical data from

gammaspectrometry and magnetometry were performed by CPRM (Rio de Janeiro Project

1.117), where, from the interpolation of these data by the methods of Minimum

Curvature and Bi-Directional Line Gridding, it was possible to process the data in a GIS environment

with the purpose of testing its potential through the integration of a ternary map of

K, eU and eTh elements and K/eTh, eU/eTh and K/eU ratios, domain map

gammaspectrometry and map of structural domains that may contribute to the

optimization of a preliminary characterization of the geological and pedological context and

thus being used in pre-field work to define domains and targets

of interest, especially in areas of difficult access, in addition to serving as a subsidy

for various branches of the geological/environmental market and related research.