The rhyolite itself comprises the REE mineralized body. Magmas with a peralkaline compositionare known to have high concentrationsof incompatible elements such as U, REE, Th, and Zr.

The rhyolite magma that developed Round Top Peak probably cooled too quickly to develop a coarse-grained texture or to develop zones with high REE concentrations. A quick cooling rate would cause a fine-grained texture of the rhyolite and even distribution of the REE minerals. The rhyolite magma was saturated in fluorine, which is reflected in the high percentage of fluorine accessory mineralsthat are distributed throughout the rhyolite mass. As the magma cooled, fluorine saturated fluids exsolved from thecrystallizing magma. These fluorine rich fluidsaccumulated in interstices and vugs between the earlier crystallized minerals anddeposited REE minerals and other accessory minerals in the interstices. The REE deposit at Round Top Peak can be classified as quartz saturated peralkaline (A-1) granite with a rhyolitic texture and a composition similar to certain pegmatites.

REE mineralization is hosted by the Round Top Peak laccolith. The rhyolite is fine grained with a microporphyritic texture. The porphyry phenocrysts consist of alkali-feldspar with albite cores, clear quartz grains, and minor brown to clear Li-mica. Within the quartz grains or crystals, inclusions along planes of crystallization have been observed. The groundmass is aphanitic and consists of quartz, feldspar, and mica with vugs or vesicles. The vugs may be lined with quartz, feldspar, fluorite, cryolite, and li-mica crystals. Some vugs are filled with kaolinite or fluorite and are surrounded by coarsely crystalized minerals. The vugs occur in bands and can be locally clustered in isolated locations. Late-stage fractionation of volatile components, such as F, CO 2 or H 2 O, from the crystallizing rhyolite probably formed these vugs.

Round Top Peak displays some pegmatitic characteristics, including an abundance of cryolite, lithium rich micas, rutilated quartz and vapor rich fluid inclusions (Price et al., 1987). Peralkaline rhyolites and pegmatites can contain an abundance of incompatibleelements including REEs. The Round Top Peak rhyolite is enriched in incompatible elements including Li, F, Rb, Y, Zr, Nb, Sn, Ta, Pb, REE, Th, and U.

Isolated zones of brown rhyolite are present and are often related to fault structures or near the contact between the rhyolite and sedimentary rocks. In these brown zones, the iron minerals are replaced by goethite and limonite giving the rhyolite a brown color. Tan rhyolite is found along the contact between the rhyolite and sedimentary rocks. Tan rhyolite can also occur as mottling in the red and pink rhyolites located near mineralized faults and the contact between the intrusive and sedimentary rocks. The tan rhyolites were probably altered by vapor phase or hydrothermal fluids and consist of kaolinite clay and residual quartz phenocrysts. Magnetite and hematite are absent or present in only trace amounts. Degree of alteration varies and can be represented by a complete replacement of the feldspars by kaolinite to a partial replacement. Multiple colored fluorites often occur as fracture fillings and replacements in the tan rhyolites that contact the sedimentary rocks.

REE distribution and grades were not affected by the hematitic alteration of the rhyolite. However, the vapor phase or hydrothermal alteration of the tan rhyolite had an impact on the REE grade. The more intensely altered tan rhyolite zones can have a lower REE grade than the other four rhyolite phases.

Typical open pit mining methods will be used, ore will be transported from the pit to a crushing plant located adjacent to the leach pads. A haul road will be pioneered to the top of the mountain and mining will begin at the upper most benches and progress downward. As mining proceeds to lower benches, a haul road will remain in the high wall to allow access to catch berms and additional mining areas. The pit is designed with sufficient area to allow for two separate working benches or faces.

The very nature of how the mineralization sits above regional topography creates a mine with very little waste material or cover. As such there is no waste rock storage facility planned for this project. Any surface material overlying the mineralization within the pit area is expected to be unconsolidated colluvium which will be used as construction materials for leach pads and roads.

The rhyolite will be mined in 20 ft. benches, the recommended height for the class of loader selected. Two 12m3 wheel loaders will load 90 tonne haul trucks to reach a daily production rate of 20,000 tonnes. The general site layout, including pits, waste dumps, infrastructure, ponds, and heap leach pads.

The initial 20-year pit was designed based on the configuration of the rhyolite laccolith. The initial 20-year pit was designed to keep all the mining to the northwest portion of Round Top. It was decided to mine this area first due to the highest drilling density in this area and in order to minimize the visual impact of the mining from the Interstate. Additionally, all the crushing and leaching facilities will be located north of Round top so this will minimize haul distances at the beginning.

Pit slopes have been designed at 45° inter-ramp wall angle. Fracturing within the rhyolite is not yet completely understood and this may affect pit slopes, at least locally. Haul roads are designed at a width of 100 ft., which provides sufficient width for two-way haul traffic and a safety berm. The maximum grade of the haul roads is 10%.

The initial mine plan was developed to remove 20 years of rhyolite from the northwest portion of the hill, proximal to the crushing plant and processing facilities.

The conceptual process flowsheet was developed for recovery of rare earth elements, lithium, aluminum sulfate and sulfate products based on scoping study testing and use of known technologies for production of lithium carbonate and sulfate products.

The run-of-mine (ROM) ore will be stage crushed to three stages to nominal 0.5 in (P 80 of 12.5 mm). The crushed ore will be conveyed and stacked on the heap pads using conveyors, grasshoppers and radial stackers. Sulfuric acid will be dripped on to the ore on the conveyor for acid cure prior to leaching.

The ore will be leached for 30 to 45 days. The pregnant solution for the first 10 days, having a higher metal concentration, will be sent to PLS pond 1. The remaining solution will be pumped to PLS pond 2. The PLS from pond 2 will be recycled back to the heap and contacted with fresh ore.

The PLS from pond 1 will be pumped to the rare earth extraction circuit. Scoping level study indicated that continuous i ........