On January 13, 2020, Mirasol announced that it signed an option agreement with subsidiaries of Newmont Corporation (“NEM”) to acquire the Inca Gold project in Northern Chile.
The agreement gives Mirasol the opportunity to add to its portfolio a district-scale and underexplored, intermediate sulfidation epithermal project in the prolific Paleocene belt of Chile. The project hosts multiple attractive targets that have not been drill tested, and it fits well with the Company’s strategy to fund drilling on high quality prospects with favorable infrastructure.
The 14,000 ha Inca Gold project is located in Region III of Chile, approximately 100 kilometers north of Copiapo and 17 kilometers east of the town of Inca de Oro. The project lies between 2,000 to 3,000 meters ASL and has good access allowing for year-round exploration activities.
Mirasol was granted the option over 5 years to earn-in 100% of the Project, subject to a 1.5% NSR royalty, by drilling 1,000 meters on the Project over 2 years; and incurring US$3 million in exploration expenditures over 5 years. Mirasol can terminate the Agreement at any time after the completion of the initial 1,000m drilling commitment.
Upon completion of this option, NEM will have the right to earn back 70% of the Project, in two stages, by reimbursing Mirasol’s exploration expenditures and either funding the delivery a NI 43-101 compliant Prefeasibility Study; or incurring a total of US$21 million in exploration expenditures over 6 years. If NEM completes its back-in right, then Mirasol and NEM will hold 30% and 70%, respectively, in a joint venture company holding the project. Mirasol will then have the option to either fund its 30% interest or reduce it to a 25% interest in exchange for a loan from NEM to fund the project development to commercial production.
The project lies within the Paleocene Belt which consists of a thick sequence of andesitic volcanics interlayered with ignimbrites and volcano-sedimentary rocks. The belt hosts both intermediate (El Peñon, Faride, Amancaya) and high (Guanaco) sulfidation epithermal deposits, as well as copper porphyry deposits (Spence, Sierra Gorda).
Locally, the project is within the Inca Del Oro mining district, which hosts Santiago Metals’ San Pedro de Cachiyuyo Cu-Au tourmaline breccia deposit and PanAust/Codelco’s Inca de Oro Cu-Mo-Au porphyry deposit. Local geology on the southern portion of the project is characterized by a thick volcanic-sedimentary sequence consisting of ignimbrites, lava flows, and volcanic breccias. The northern portion consists of an older sequence of intensely folded and faulted ignimbrites and volcanic breccias. These two geologic domains are separated by a regional NE lineament mostly covered by Atacama Gravels.
The completed surface and prospecting activities to date have identified five target areas, none of which have been drill tested. The two main targets, the Sandra and Vania prospects, are the focus, and the other three prospects areas (Rincon, Guerda, Inca North) are secondary priorities at the moment.
Located at the southwestern border of the property, Sandra is the better-known target where a large hydrothermal system with development of intermediate sulfidation mineralization has been recognized. Mirasol will initially focus most of its exploration efforts on this prospect. Mineralization at Sandra comprises of at least five subparallel trends striking NW within an area of 2.5 kilometers x 4 kilometers, with continuous individual vein trends extending over lengths of up to 1.2 kilometers with wide individual veins (up to 3 meters) and intervening sheeted vein zones (20 meters) (see Figures 3 and 4). Vein textures are comprised of brecciated and crustiform-colloform banding with commonly bladed textures. Multiple pulses of vein fill is observed with a first stage of crystalline quartz with elevated Cu-low Au grades, generally occupying the margin of the veins at the contact with host rocks, and a second stage of colloform-crustiform banding with fine-grained quartz and abundant Mn oxides, sulfide-rich bands (now completely leached and replaced by hematite), high Ag-Zn-Pb (±Au) values, including:
The Sandra prospect may potentially host concealed or blind veins.
Mirasol´s exploration plans include a systematic geological mapping and sampling program as well as electrical IP geophysics to aid in the selection of the best targets for the maiden drill program. Structural mapping and interpretation will be used to gain a clear understanding of the controls on mineralization and to define drill targets. Mirasol will use a small portable diamond drill rig to minimize environmental impact during the first drill campaigns, which will include up to 1,500 meters as an initial test-of-concept at this exciting under-explored prospect.
Vania, the next highest priority, is a concealed porphyry target located on a regional northeast lineament, below the Atacama gravels, with subtle hydrothermal alteration zones identified in the surrounded host rocks. Grid soil samples have identified Au anomalies surrounded by a halo of pathfinder metals (Hg-Mo-Ag-Ni-As) coincident with a magnetic depletion zone at the intersection of northwest and northeast lineaments.