The Central Mineral Belt (CMB) of Labrador encompasses largely Proterozoic rocks of six supracrustal sequences ranging from the 2178 Ma Post Hill Group to the 1225 Ma Seal Lake Group. The focus of Aurora’s uranium exploration is in the eastern portion of the CMB in deformed greenschist to amphibolite facies rocks of the Post Hill and Aillik groups. The thickness of the Post Hill Group volcano-sedimentary package is ~2,700m. Lithologies include basal quartzite overlain by paragneiss, amphibolite, metapsammite, metapelite, quartzite and pillowed metabasalt. The overlying Aillik Group is ~5,000m thick, dated at 1883 to 1856 Ma. The lower portions include conglomerate, sandstone, siltstone, shale, limestone and minor dacite, rhyolite and basalt. The upper part is dominated by felsic volcanic rocks, including ash fall and flow, rhyolite and rhyolite porphyries.
The volcano-sedimentary package is cut by numerous granitic intrusions, including:
-1858 Ma foliated quartz-feldspar porphyritic granites
-1800 Ma foliated Kennedy Mountain Intrusive Suite
-1720 Ma granitoid plutons of undeformed syenites, alkali-syenites, alkali-granites and granites
-1650 Ma Monkey Hill Intrusive Suite of biotite quartz monzonite to monzodiorite
Regional geologic maps of Labrador can be viewed on the Government of Newfoundland and Labrador website at: http://www.nr.gov.nl.ca/mines&en/geosurvey/maps/
Aurora’s exploration activities are focused within a 10 km x 3 km area around the Michelin deposit. Local geology consists of foliated, ENE-striking, felsic and mafic Aillik Group rocks and biotite-hornblende-granites. Host rocks of the Michelin uranium deposit are foliated, fine-grained to porphyritic rhyolite flows cut by unmineralized mafic dike swarms and granite. The Michelin deposit consists of a main tabular 1.2 km long by 5-30m thick zone and minor footwall and hanging wall lenses, as depicted in the figure below. Rocks dip 50-60° SE and are characterized by albite, sodic amphibole, hematite and magnetite alteration. The oblique intersection of foliation and stratigraphy create a steep southwest plunge to mineralization, which has been drilled to depths of 800m.
Michelin uranium wireframes, looking west
The CMB contains resources of 164M lb U3O8, of which 140M lb are owned by Aurora. Aurora has identified significant uranium resources at Michelin and Jacques Lake, and satellite deposits at Nash, Inda, Gear and Rainbow. Michelin is by far the largest of these resources (107 M lb U3O8) and is the cornerstone of Aurora’s activities.
The map below shows Aurora’s CMB claim boundary and surface uranium mineralization. For more information on any of our six deposits, please click its name on the map.
The mineral resources are reported by using cut-off grades of 0.05% U3O8 for underground mineable material and 0.02% U3O8 for open pit mineable material. A technical report title ‘Michelin Uranium Project, Labrador Canada, NI 43-101 Technical Report on Preliminary Assessment’ dated 1 August, 2009 was filed by Fronteer Development Group Inc (the previous owner of Aurora) on SEDAR. The Technical report has been reviewed by Dave Princep (Principal Geologist, Resources) with Paladin Energy. To the best of Paladin’s knowledge there is no new information that would make this disclosure of the mineral resources inaccurate or misleading.
The table below summarizes Aurora’s NI 43-101 compliant resources in Labrador.
Please click on table to expand or click here to view as PDF.
Metallurgical testing of Michelin samples indicates uranium recoveries of 85-90% using acid leach methods. Potential mining would be by open pit and underground methods. Mine and mill access would require a 140 km long road and power line to be built from Happy Valley-Goose Bay. The nearby Jacques Lake deposit has also been evaluated for metallurgy and mine design to supplement Michelin production. The Rainbow, Inda, Nash and Gear deposits are considered possible future development targets but are not currently included in Aurora’s development plans.
The Michelin deposit is Aurora's most advanced project. It is located 40 km south of Postville and 80 km from Makkovik in the eastern portion of the Central Mineral Belt. Michelin was discovered in 1968. Drilling by Aurora from 2005 to 2014 increased the Michelin resource from 18 million pounds to 107 million pounds of uranium oxide. The deposit is open at depth and along strike and further drilling is planned. Additionally, infill drilling is planned to increase the measured and indicated categories.
Jacques Lake Deposit
The Jacques Lake deposit was discovered by Aurora in 2005. The resource of 20 million pounds of uranium oxide is located 26 km east of Michelin. It is one of the few new significant uranium discoveries made in the world over the past ten years. Jacques Lake remains open for expansion.
Located 3 km south of Michelin, the Rainbow Zone was first drilled in 1970. Subsequent drilling in 1975, and by Aurora in 2006, confirmed near-surface uranium mineralization. The Rainbow deposit remains open for expansion.
Nash, Inda and Gear
The Nash, Inda and Gear deposits are three deposits in the northeast portion of Aurora's mineral tenure. Resources range from 1 to 5 million pounds of uranium oxide. These deposits were drilled by Aurora in 2006 and 2007. The Nash, Inda and Gear deposits remain open for expansion.
The CMB offers excellent potential for additional discoveries. Aurora’s exploration program is focused on increasing resources in the Michelin area through prospecting, mapping, airborne and ground magnetic and radiometric surveys, glaciation studies, core relogging, 3D geologic modelling, data compilation, prospectivity mapping and drilling. Exploration is based from the fly-in/fly-out Michelin camp, located 140 km northeast of Happy Valley-Goose Bay, using fixed-wing and helicopter air support to move supplies and personnel. The Michelin field camp accommodates up to 40 people, including 20-30 seasonal staff hired from coastal Labrador communities.