%0 Conference Proceedings
%4 sid.inpe.br/marte2/2017/10.27.15.34.34
%2 sid.inpe.br/marte2/2017/10.27.15.34.35
%@isbn 978-85-17-00088-1
%F 59336
%T Resultados preliminares de espectroscopia de reflectância em testemunho de sondagem (AG-01) na região da mina de Pb-Zn-Ag (Ba-Cu) do Perau, leste do Paraná, Cinturão Ribeira, Província Mantiqueira
%D 2017
%A Costa, Manoel Augusto Correa da,
%A Perrotta, Monica Mazzini,
%A Silva, Anderson Dourado Rodrigues da,
%@electronicmailaddress manoel.costa@cprm.gov.br
%E Gherardi, Douglas Francisco Marcolino,
%E Aragão, Luiz Eduardo Oliveira e Cruz de,
%B Simpósio Brasileiro de Sensoriamento Remoto, 18 (SBSR)
%C Santos
%8 28-31 maio 2017
%I Instituto Nacional de Pesquisas Espaciais (INPE)
%J São José dos Campos
%P 5849-5856
%S Anais
%1 Instituto Nacional de Pesquisas Espaciais (INPE)
%X The Ribeira mobile belt in the Mantiqueira Province, southeastern Brazil, is historically known by the occurrence of important Pb-Zn deposits. The Perau Pb-Zn-Ag (Ba-Cu) deposit is interpreted as a sedimentary exhalative (SEDEX) system that was metamorphised at greenschist and amphibolite facies conditions. Here we present preliminary results on reflectance spectroscopy applied to mineral mapping of host rocks and alteration zones along the drill core AG-01 in the Perau mine. Visible and infrared (VNIR-SWIR; 0.4-2,5 µm) lab spectroscopy was conducted using the ASD-FieldSpec-3 Hi-Resolution spectrometer. Contact spectral measurements allowed the identification of distinct mineral groups, including Fe/Mg-chlorites and biotites, sericites (illite and muscovite), smectites (montmorillonite), amphiboles (hornblende and actinolite), Fe-carbonates and sulphates (gypsum). Gypsum was preliminarily identified in spectral mixtures dominated by Fe-carbonate absorption features. Compositional trends of Mg-rich chlorites (FeOH absorption < 2.248 µm) and phengitic sericites (AlOH absorption > 2.214 µm), as well as the presence of actinolite (secondary MgOH absorption < 2.386 µm) and Fe-carbonate (diagnostic Fe²+ absorption > 1.240 µm), are strongly correlated with hydrothermal alteration zones close to the Pb-Zn-Ag (Ba-Cu) ore body, and suggest a mineral system dominated by fluids rich in Fe, Mg and Ca. This mineral assemblage identified by reflectance spectroscopy is coherent with others SEDEX classic deposits in the world (e.g. HYC deposit, McArthur Basin, Australia), except by the dominant presence of Mg-rich chlorite in the proximal alteration zones.
%9 Geologia
%@language pt
%3 59336.pdf