The Aguas Calientes mineral exploration concession, which includes the Piedra Iman copper gold project, is located in the district of Chinandega approximately 200km northeast of Managua. This concession was acquired by Royal Road in 2017 as part of the Caza Gold transaction.
Piedra Imán is a copper and gold project which shares many geological similarities with "cordilleran-style" Iron Oxide Copper Gold (IOCG) systems such as those which occur in Chile and Peru.
Gold and copper mineralisation is hosted within a dacitic porphyry and a magmatic breccia. The porphyry is host to more gold-rich (up to 1 meter at 70g/t gold in drilling) quartz-albite-actinolite-tourmaline veins whereas the magmatic breccia hosts stockwork style copper veinlets. The porphyritic rock is the earlies of the intrusive phases in the district.
The Piedra Imán project was initially explored in the early 1970’s by Noranda Inc. Noranda’s work included the drilling of 17 shallow diamond drill holes and the development of one 300m long exploration adit. Noranda’s drilling and underground sampling intersected significant widths of copper mineralization including DDH-851 (36.6 meters at 1.13% Copper), DDH-876 (14.8 meters at 1.65% Copper), DDH-846 (14.3 meters at 1.42% Copper) and DDH-818 (9.1 meters at 1.50% Copper). Samples were only sporadically assayed for gold, but drilling results included one interval of 3.6 meters at 6.3 g/t gold. These results were provided in analogue format, are historic in nature and have not been verified by a qualified person. Historic maps indicate that the exploration adit intersected gold and copper along its strike length with gold only mineralization dominating the southwestern end of the adit and combined copper and gold mineralization dominating the northeastern extent of the adit. There are no reports available to verify the style of adit sampling or to confirm the underground grades labelled on historic maps. Noranda abandoned the project due to the onset of hostilities related with the Sandinista conflict in 1978.
Caza Gold acquired the project in 2013 and focused their exploration work on mapping, soil and rock-choip geochemistry.
Caza Gold’s rock chip and mapping program highlighted the area represented by more gold-rich mineralization and returned grab samples up to 60.7 g/t gold.
In 2017 Royal Road completed a horizontal saw-cut channel sampling program at the project. Channels were cut across rock faces which exposed the magmatic breccia and the porphyritic intrusion. A total of 9 channels were cut and sampled on 1 meter intervals over a total strike distance of approximately 400m. Some significant results included:
Channel 4 – 20 meters at 1.10% copper and 5 meters at 0.95% Copper
Channel 8 – 8 meters at 1.05% copper and 1.13 grams per tonne gold
Channel 7 – 5 meters at 0.28% copper and 2.50 grams per tonne gold
Channel 2 – 9 meters at 0.70% copper
Channel 5 – 6 meters at 0.87% copper
In early 2018, Royal Road completed a 9-hole reverse circulation scout drilling program at the project. Results from this program included best intersections of PI-006; 8 meters at 9.3 grams per tonne gold and 31 meters at 0.5% copper, PI-008; 103 meters at 0.36% copper and PI-007, 40 meters at 0.38% copper.
Recent work at Piedra Iman has identified the porphyry-hosted area of the project, where gold is related to quartz-tourmaline veins, as a potential high-level part of the mineralizing system (with the more copper-rich magmatic breccia representing a distal component). Further mapping and petrographical work is underway with a view to defining drill targets if warranted.