The large La Curva gold project in Santa Cruz hosts three drill-ready prospects along the six kilometers La Castora gold trend and additional prospects in the Curva West area. La Curva was staked in 2005 to secure alteration anomalies identified by Mirasol’s generative team. The La Curva project forms part of a newly recognized low sulphidation precious metal district within the prolific Deseado epithermal province which contains four operating multi-million ounce gold and silver mines and an additional advanced stage mine development that is scheduled for production in 2018. The results from an 18 hole, 2,550 m, Phase I diamond core drilling (DDH) program from the La Castora Trend at the La Curva were announced in February 2018.
A Letter of Intent with OceanaGold was signed in February 2017, followed by the signing of the definitive exploration and option agreement on May 18, 2017. OceanaGold has an option to acquire 70% interest over an eight-year period. The first earn in option to 51% requires an exploration spend of US$ 7 million and cash payments to Mirasol of US$ 1.5 million over four years. This includes a first-year commitment of US$ 1.25 million in exploration spending with 3,000m of drilling and a cash payment of US$ 100,000. Additional deal terms include the right for Mirasol to retain 25% and to require OceanaGold to provide the potential project development financing.
Phase I drilling at the La Curva Castora Trend has provided an initial test of three prospects: Cerro Chato, Loma Arthur and SouthWest. This drilling campaign has intersected widespread pervasive argillic alteration, silicification and Gold+Silver mineralization indicative of a low-sulfidation epithermal gold system. Mineralization is developed as a series of veinlet zones within the structurally prepared welded ignimbrite wall rock, as disseminations within laminated water lain sediments and as matrix fill in phreatomagmatic and dome margin autobreccia bodies. Preliminary geological interpretation suggests the Castora Trend prospects represent a series of intrusive dome related maar diatreme breccias.
Targeting efforts are underway for a Phase II drilling at the Castora Trend planned for the first quarter of 2018. This drilling will be designed to provide deeper testing of selected mineralized zones and permissive structural settings, and testing for the presence of favourable/receptive host rocks that could promote the development of wider, high grade veins and breccias.
Assay results from Phase I drilling confirm the presence of a large Gold+Silver system within the Castora Trend with broad zones of anomalous Gold+Silver intersected including:
47.9 m at 0.48 g/t Au and 2.1 g/t Ag (CC-DDH-01)
106.2 m at 0.61 g/t Au and 2.7 g/t Ag (SW-DDH-02)
The better down hole intersections at 0.3 AuEq60*g/t cut off include:
19.65 m grading 0.72 g/t Au and 2.6 g/t Ag, including 0.80 m grading 6.12 g/t Au and 18.6 g/t Ag, and 5.75 m grading 1.24 g/t Au and 2.0 g/t Ag, including 0.85 m grading 5.99 g/t Au and 5.9 g/t Ag (CC-DDH-01).
13.00 m grading 1.22 g/t Au and 0.7 g/t Ag, including 7.4 m grading 1.81 g/t Au and 0.7 g/t Ag (LA-DDH-04).
6.20 m grading 2.33 g/t Au and 31.1 g/t Ag, including 1.80 m grading 6.88 g/t Au and 84.9 g/t Ag, and 26.7 m grading 0.82 g/t Au and 2.2 g/t Ag, including 1.45 m grading 3.50 g/t Au and 11.3 g/t Ag (SW-DDH-02).
Two distinct stages of gold mineralization are recognized:
Stage 1: This stage is characterized by broad zones (up to 106.2 m downhole) of lower-grade, early quartz-pyrite.
Stage 2: This is a later, overprinting phase of higher-grade multi-pulse epithermal veins and veinlets with individual assays up to 0.8 m grading 12.72 g/t Au and 145.4 g/t Ag (SW-DDH-02).
Exploration is also in progress at the Curva West prospect to define drill targets where previous Mirasol sampling identified float blocks of epithermal vein and breccia in a prospective geological setting that assayed up to 20.73 g/t Au and 36.4 g/t Ag.
To learn more about La Curva, see our News Releases and the detail project presentation available in the following sections.
Additional Explanatory Notes: * AuEq60 is the sum of the value of gold and silver in a given interval represented as a gold equivalent g/t value calculated via the formula: Au assay in g/t + (silver assay in g/t ÷ 60)