Osiris
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Property Type
Porphyry Cu Project
Size
10,000 ha
Status
Available for Partnership
Exploration Stage
Pre-drillinng
Rock chip assay sampling, geological and alteration mappingLocation
- Mio-Pliocene age mineral belt in northern Chile
- 17km from Los Azules, an advanced-stage porphyry Cu project
The 100% owned Osiris Cu project is located within the fertile Miocene belt of Chile which is host to several high-profile advanced projects such as Altar, Los Azules, El Pachon and Pelambres, among others. Osiris was staked by Mirasol through its project generation program and comprises approximately 10,000 ha of exploration claims. Mirasol’s detailed surface exploration, which included geological mapping, geochemical sampling and alteration analysis, has defined two drill-ready concealed porphyry Cu-Mo-(Au) targets.
Mirasol has initiated a search for an exploration partner to advance and drill test this attractive project.
At the regional level, Osiris is located within the southern extension of the Miocene Age El Indio high sulfidation epithermal belt and northern extension of the Southern Miocene porphyry belt, both of which are well-endowed regions in Chile and Argentina. Mineralization at Osiris appears to be controlled by the same prominent northwest striking lineament, a key regional feature which also controlled the emplacement of the late Miocene Los Azules, an advanced-stage porphyry Cu project (McEwen Mining Inc - Indicated Resources: 10.2 B lbs at 0.48% Cu and 1.7 Moz at 0.06 g/t Au[1]) located some 17 km to the southeast.
At a project scale Osiris is characterized by Paleozoic biotite migmatites and weakly foliated diorite lithologies, which have been cross-cut by Carboniferous-Permian-Triassic intrusives and several diorite dykes. Mineralization is interpreted to be associated with Miocene aged (13.7 Ma) diorite to rhyolite porphyritic intrusives and structurally controlled magmatic-hydrothermal breccias associated with west-northwest and north-northwest regional structures. The long-lived magmatism, multi-phase porphyritic intrusives together with the observed structural preparation is considered highly favourable for porphyry Cu-Mo-(Au) mineralisation.
Cu-Mo-(Au) rock chip geochemistry and alteration spectral analysis have defined two targets, at the Filo Gordito and Northern Osiris, with Cu mineralization occurring as supergene oxides developed from primary chalcopyrite. Peripheral to these two targets, geochemical surveys have also defined epithermal polymetallic Ag-As-Sb-Te-Bi-Pb±Au anomalies. In addition, on the southeast part of the Filo Gordito target, a large 3 x 2 km phyllic alteration footprint affects porphyritic units and intrusive breccias. The intrusive breccia has strong quartz-sericite alteration, which is cut by quartz sericite veins (D-style porphyry veins). This phyllic alteration, locally displaying an alunite overprint, is considered to be typical of a porphyry environment and may represent the mid-upper levels of the system and vectors to potentially higher Cu-Au grades within the deeper and underlying the potassic zone.
[1] McEwen Mining Inc: NI 43-101 Technical Report-Preliminary Economic Assessment Update for the Los Azules Project, Argentina, dated September 1, 2017. The mineral resource estimate was prepared under the direction of Robert Sim, PGeo, with the assistance of Bruce Davis, PhD, FAusIMM.
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