The Company secured agreements over two potential near-term copper/gold projects near the city of La Serena in 2016. The development of the projects (Farellon and Maria Luisa) was progressed through 2017 under a joint venture farm in by a Canadian Listed Company (Altiplano Minerals Limited) whereby they committed to provide US$2 million in funding to earn a 50% equity in the two projects. During 2017, under the operatorship of Comet, a 400-metre development decline was completed behind the primary structural target at the Farellon. Extraction and sale of ore from the operation commenced in December 2017, following cross cutting to the mineralised zone. Shortly after commencement of sales, an offer was received from Altiplano to purchase Comet’s 50% share in the joint venture – which the Company accepted.
Full details of the development of these projects and the transaction between Comet and Altiplano are provided on Altiplano’s web site (www.altiplanominerals.com).
Farellon and Maria Luisa Projects in northern Chile are focused on the potential mining development of copper and gold mineralisation. To date, small producers have exploited copper and gold mineralization at both properties via underground workings but they have lacked the capital to define the resource and develop the small mines into modern deeper and more sustainable operations.
Subduction of oceanic crust under the Chilean continental plate resulted in the formation of magmatic volcanic and plutonic arcs during the Jurassic to Cretaceous periods. Between the Jurassic and present day, eastward migration of these arcs led to the formation of the major tectonic features known as the Coast Range, Central Valley and the Andean Cordillera. The area of the Farellon and Maria Luisa Properties is located within a region of major volcanism and plutonism related to the Jurassic-Cretaceous continental plate subduction event. During this time, extensive fault systems and shear zones were active in the area, including the Atacama Fault system. The Atacama Fault Zone trends north-northeast for over 1,000 km, coincident with the volcanic-plutonic arc that forms the Coast Range. The fault zone and its splays are closely associated with a significant number of iron, copper (Cu) and copper-gold (Cu-Au) deposits found in the Coastal Belt.
At the Farellon Property, copper and gold mineralization occurs within east-northeast trending vein systems hosted within a Cretaceous-aged granite to granodiorite unit, most significantly within the Farellon, Laura and Rosario Veins. Mineralization within the Farellon vein structures consists of Cu+/-Au, with grades of the reported historic mining averaging on the order of 2.5% Cu and 0.5 g/t Au. The Farellon area veins historically are known for their consistent, high grade copper values.
The Farellon Project consisting of the Farellon, Laura and Rosario vein structures offers excellent potential to develop high grade copper-gold vein based resources. Based upon work conducted by Comet and past exploration, including underground and surface sampling along with mapping and three-dimensional modelling there is potential for the three vein structures to host a total of 200,000 to 600,000 tonnes of vein material with a range of grades of 1% to 2.5% Cu and 0.1 to 1.0 g/t Au.
The Maria Luisa Property is located in an area with well-defined structural systems, most notably are major northwest and north-south trending strike-slip faults. Mineralisation in and around the Maria Luisa Property is found primarily in the extensional northwest and east-west trending vein systems hosted in the chloritic- and propylitically-altered granite and volcanic rocks. The mineralisation is characterised by mainly copper-gold (+/-iron oxides) with associated pyrite, chalcopyrite and bornite sulphides. The Maria Luisa veins consistently yield significant grades of gold, with the recent selective mining (2013 to 2015) of over 600 tonnes yielding an average grade of approximately 6.85 grams per tonne (g/t) Au and 1.89 percent (%) Cu.
A mineralisation target has been defined for the Maria Luisa Property based upon the historic resource estimates, recent underground sampling and mapping conducted by Comet, historic production records and three-dimensional modelling which ranges from 200,000 to 400,000 tonnes with a range of grades of 1.5% Cu and 2 g/t Au to 2.5% Cu and 5 g/t Au.