New Insights into the Evolution and Footprints of the Paraíba Au-Cu-Mo Deposit, Alta Floresta Mineral Province (Brazil), through Integration of Spectral and Conventional Methods

Abstract

The Paraíba is an Au-Cu-Mo deposit located in the southern part of the Amazon Craton, in the Alta Floresta Mineral Province, Mato Grosso State, Brazil. It is composed of Au-Cu-bearing quartz veins and Cu-Mo-rich hydrothermal breccias and stockworks, both associated with several hydrothermal alteration zones. The integration of spectral (reflectance and imaging spectroscopy) and conventional techniques (core logging, petrography, mineral chemistry, and scanning electron microscopy) was applied to map alteration zones, identify mineral parageneses, and determine the evolution of the deposit to generate a solid proxy for mineralized zones. This study shows an overlapping of two different mineralization systems in the AFMP, referenced hereafter as alteration Groups 1 and 2. Group 1 is an Orogenic Gold system related to Au-Cu-rich quartz veins in phyllonites and mylonites. Group 2 is a Cu-Mo Porphyry system related to a syenogranite intrusion and the subsequent generation of several hydrothermal alteration zones, Cu and Mo hydrothermal breccias, and stockwork mineralization. This study reveals several alteration footprints, guides, and vectors for the mineral exploration of these deposits in the Alta Floresta Mineral Province.