Atlas Lítio Brasil Ltda. (ALBL), the Brazilian subsidiary of Atlas Lithium Corp., owns the mining rights to the Neves Lithium Project.
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Summary:
Deposit Type
The mineral systems in highly evolved magmatic sources of REEs and lithium are controlled by the degree of fractionation. In granitic rocks with a high degree of fractionation, lithium and tantalum is more abundant. This characteristic defines the spatial zoning and distribution of pegmatite mineralogy with respect to the parent magma (pluton). The relationship between fractionation and REE concentration has not been determined in eastern Minas Gerais. Based on geochemical studies, Morteani et al. (2000) show that the pegmatites of the Araçuai-Itinga/orogen cover the complete fractionation interval exposed in the Eastern Brazilian Pegmatite Province (EBPP).
The Araçuaí-Itinga lithium pegmatites are controlled by structure which can be concordant or discordant with respect to schist foliation. The work of Sá (1977) shows that pegmatites discordant with schist foliation predominate, with strikes varying from 40° to 80° and high angle dips in the northeastern quadrant of the exploration area. The pegmatite bodies tend to be tabular with little variable thickness and are hosted in the schists of the Salinas Formation.
Local and Property Geology
In eastern Minas Gerais, lithium-rich pegmatite mineralization is hosted in metamorphosed Salinas Formation shales (cordierite-quartz-mica schist) and is either concordant or discordant with schist foliation. The pegmatites occur as tabular bodies with thicknesses from 2 m to 36 m. Laterally, mineralized bodies vary from 40 m to 350 m in length and are primarily made of quartz, alkali (K-) feldspar (perthitic microcline), albite, muscovite, spodumene, and petalite. Spodumene makes up approximately 20% of the mineralization, with K-feldspar and albite constituting approximately 35%, quartz approximately 35%, and muscovite less than 10%.
Schists of the Salinas Formation outcrop in the Neves exploration areas (ANM No. 833.331/2006, 832.925/2008, 833.356/2008, and 833.639/2003) which were intruded by magmatic suite G4 monzogranites of the Teixerinha batholith and pegmatites hosting lithium rich spodumene, columbite-tantalite, and gem quality tourmalines.
The exploration area is covered by a thick (five meter) horizon of sandy to silty soil brownish ochre in color, with blocks (<30 cm) of pegmatites from adjacent artisanal mines or displaced by heavy rainfall and steep relief. The Neves area is heavily vegetated which makes it difficult to identify outcrop, however, historical artisanal mining activity has exposed the deposits. For decades, the Neves exploration area has been developed for tourmaline resources and gems (spodumene, triphane, petalite, columbite-tantalite) at some farms within the mineral right. The artisanal mines are inactive today. Tailings from these mines were disposed of in piles or "dumps" scattered throughout the area, and in some places complicating access to outcrop.
Cordierite-quartz-mica schists of the Salinas Formation outcropping in the Neves exploration area are light gray to black in color, banded, and occasionally with quartzitic composition. The banding reflects variations in the proportions of biotite to muscovite (dark bands) and the sum of quartz and feldspar (light bands). These metamorphic rocks are in the green schist facies with foliations perpendicular to the strike which varies between N30°E and N50°E. High angle dips (45°-80°) have been observed in contact with intrusive igneous rocks. Syn-tectonic quartz veins are concordant with the schist foliation, exhibit local boudinage structure, and are one centimeter to 30 cm thick. The Salinas Formation schists host significant pegmatite bodies, ranging from 1 m to 2 m thick to 10 m to 30 m thick and up to 40 m to 450 m long.
Six mineralized pegmatite outerops have been mapped in the western portion of the Neves exploration property, that are 2 m to 29 m thick and up to 200 m long, where exposed at surface. The strike of the pegmatites is sub-parallel to oblique to schist foliation, locally homogeneous, and composed of quartz, feldspar, muscovite, black tourmaline, and locally spodumene and petalite. The spodumene and petalite occurs as altered white clay at surface and as phenocrysts disseminated throughout the host rock.
In the eastern portion of the property, several pegmatite bodies outcrop along the main drainages in schists of the Salinas Formation. The pegmatites follow a strike trend of N5°E to N30°E and are concordant with schist foliation.