SPECTRAL LIBRARY AS A SUPPORT FOR THE CHARACTERIZATION OF GEODIVERSITY IN THE CAMPINAS SUB-BASIN (BA, BRAZIL)

Abstract

- Remote sensing has been increasingly used for the interpretation and characterization of targets on the Earth's surface, as in mineral prospecting through spectroradiometrics, which aims at spectral discrimination of specific targets, based on their spectral reflectance curve. The collection of different spectral signatures organizes a spectral library, which works as a digital catalog of targets, to be studied and consulted for environmental purposes.  Thus, this research was one of the spectral patterns as a support for the elaborated research of activity inventories for library purposes for the characterization of geodiversity in the Campinas Sub-Basin, in the conservation state of Bahia, where it understands as Neoproterozoic sedimentary assumptions, with the occurrence of essentially carbonate units in the Una group. A collection of 27 spectral data was used in this study, with 22 samples of carbonate rocks and 5 of soils, collected in the municipalities of Morro do Chapéu, Várzea Nova, and Jacobina, using a VIS-NIR-SWIR spectroradiometer. In the spectra of the rock samples, all of them present the diagnostic bands of CO₃²⁻ in the range between 2300 nm and 2350 nm, characteristic of carbonate minerals (calcite and/or dolomite), in addition to other absorptions resulting from the common impurities found in the composition of these rocks. Soil spectra show absorption features resulting from iron oxy-hydroxyls in the VIS-NIR range and clay mineral absorptions in SWIR.