Mineral Resources

The Morro dos Seis Lagos Alkaline Carbonatte Complex occurs in the northwestern part of Amazonas state (municipality of São Gabriel de Cachoeira). The complex is defined by three circular bodies aligned according to NS direction and are identified as Morro dos Seis Lagos, Morro do Meio and Morro do Norte. The Morro dos Seis Lagos body is known as the largest worldwide Niobium deposit hosted lateritic crust over 200m thick, which is composed essentally of goethite and hematite, derived from siderite carbonatite. This crust hosts rare earth (RE), niobium (Nb), ttanium (Ti) and manganese (Mn) ores that are predominantly generated by hydrothermal and weathering processes. The purpose of the Seis Lagos Mineral Resources Report is to integrate the compiled and obtained data in the present work to define the economic potential of RE in the Alkaline Complex of the Morro dos Seis Lagos. The report presents the descriptons of the drill cores with their respective mineralogical characteristics and lithological variations to contextualize it as a RE deposit. The main minerals identified by X-ray diffracton are Fe and Mn oxyhydroxides; Ti-Nb oxides, and aluminate phosphates of RE, among others. The Nb minerals of economic interest identified in the laterite crust are ilmenorutle, Nb-rutle, and Nb-brookite. Besides which indicatng significant concentratons of Nb and Ti, they present a closely spatal relationship with the minerals of the ferruginous crust. Although it contains high levels of Nb, comparing to Araxá, for example, its associaton with the laterite crust requires unusual mineral processing that should address the dominant presence of iron, which can hinder the ore processing. The RE minerals are also related to laterite crust and the RE elements can be extracted as byproducts. The main RE minerals are monazite, florencite and cerianite, which result in some intervals with up to 2% of Ce, mainly in the Esperança basin. However, these minerals are secondary ones immersed in the iron oxy-hydroxide minerals of the lateritc crust. The resultng texture is fne-grained minerals occurring as isolated crystals or in aggregates of minerals enveloped by the ferruginous matrix of the lateritc crust. Also, there has been identfed presence of Th, which according to the varios samples is ofen closely associated to RE minerals. In the case of high contents of this element, it can be a major obstacle for mining this deposit. At the most superfcial levels of the ferruginous crust, Th phosphates are observed as isolated crystals in pores and voids of the lateritc crust. Whereas in the carbonatte, thorbastnaesite occurs in greater proporton and contains Ce in its compositon. The lateritc crust is cut by manganese lenses composed mainly by minerals of the cryptomelane group, such as hollandite, and pyrolusite in a lesser proporton. In these lenses, the presence of cerianite associated with the hollandite is common, indicatng that the crystallizaton process of these minerals is contemporaneous. The obtained data allowed to calculate the RE resource of the Morro dos Seis Lagos deposit. Given the current worldwide demand for critcal RE’s (Nd, Eu, Tb, Dy, and Y = CRE, Σ of the critcal RE's) and the presence of high levels of these elements in the deposit, a separate resource estmaton for these elements was carried out. The measured total RE resource is 250,000 tonnes (mt) @ 0.65% RE2O3, and the critcal RE's is 50 mt @ 0.13% CRE 2O3. Also, the measured niobium resource was recalculated with the analytcal results obtained in this project, which has 1.15Mt @ 2.99% Nb2O5, whereas the Uaupes Project data had been estmated with 1.09Mt @ 2.85% Nb2O5 of measured resource. Locally, the Seis Lagos deposit presents areas with various geochemical anomalies of elements such as Sc, Zn, V, Ba, among others. For example, Sc, which is a commodity with high demand in the technological market, may have the contents in this deposit greater than 500 ppm in the carbonattc porton. Thus, the anomalous contents of these elements need to be beter characterized through additonal studies to determine their economic potentality.

The Batolito Pelotas - Tijucas Terrain Project is an integrated geologicalgeophysical map at scale 1:750.00, comprising 20 cartographic sheets at the scale 1:100,000, which covers an area of 60,000 km2. The project is located in the SulRiograndense Shield, represented by association of magmatic arc (Batolito Pelotas) and by associations of the reworked basement and supracrustal sequences (Tijucas Terrain). This report consists of regional integration of lithological, structural, geochemical, geophysical and mineral occurrence data, together with field and laboratory data. The aim of this study is to characterize the metallic mineralization and its controls. The absence of mines in operation of metallic assets, although existing in the past, points to greenfield area. However, a better geological and geotectonic knowledge of the studied area can increase the attractiveness for the mineral industry, since this study could improve the understanding of mineral potentiality. Many regional sections have been done that improved the geological mapping and its understanding. The obtained results from the lithochemical and petrographic data show that in some specific areas is necessary a systematic mapping for a better geotectonic understanding. In this project, it was established that the separation between the Batolito Pelotas and the Tijucas Terrain is limited by the Porto Alegre Magnetic Anomaly. Following definition the Encruzilhada Block is part of the Tijucas Terrain. The Batolito Pelotas comprises five suites: Viamão, Pinheiro Machado, Cordillera, Cerro Grande and Dom Feliciano. It was also adopted the separation of the Jaguarão Block, In the southeastern part of the SulRiograndense Shield occurs the Jaguarão Terrane as separated unit. The isotopic signature of the available Batolito Pelotas samples shows two patterns of TDM values, one around 2.0 Ga and another of 1.7 Ga, indicating a signature of mixed sources for these rocks, an oceanic plate with a probable source juvenile (1.1 Ga) and another Arquean (≈3,0 Ga) or  Paleoporterozoic. The mineralizations explored in the Batolito Pelotas and Tijucas Terrain have a relationship with volcanic rocks, indicating that epithermal deposits may be present in a more common way than the one pointed so far for the region. These data also indicate that northern part of the Batolito Pelotas corresponds to an upper portion of continental magmatic arc by the presence of great amount of volcanic rocks and of epizonal granites.