Prism and Miranda “scout” drill-tested a large low-sulfidation epithermal gold system at Cerro Oro, where mapping and sampling indicate the potential for multiple high-grade gold veins occurring within broader zones of lower grade disseminated and fracture controlled mineralization. The original planned program called for four to five angle holes totaling 1,200 meters.
Due to failure to obtain important surface easements in a timely manner, the drill program was limited to three angle holes totaling 472 meters. Miranda will continue to work on easement agreements.
All three holes completed have significant mineralization.
Cerro Oro drilling highlights (refer to Table below):
? CO-001: 1m @ 3.67 g Au/t in a locally coliform, sulfide-quartz breccia, interpreted to be a down-dip and strike extension of the “Victoria Vein”.
? CO-003: 1.45m @ 3.53 g Au/t in a heterolithic, matrix supported hydrothermal breccia that forms a contact zone with a dacite porphyry dike. The main breccia is subsequently injected by finer “fluidized” breccia. Several crosscutting sulfide veinlets occur in matrix and clasts. This is a newly recognized mineralization style on the project and indicates complexity and multi-stage mineralization in the system.
The Colombian Ministry of Interior has notified Miranda that a “Consulta Previa” with nearby indigenous peoples will be required for any additional work on the project. Miranda has started the “Consulta Previa” process, and intends to pursue it expeditiously.
Prism has decided to withdraw from the joint venture in the Cerro Oro project; partially because the planned drill program is delayed, and because Prism intends to focus on the exploration of their recent acquisition of the past-producing Huampar Mine in Peru, a historic silver-gold producer.
As a consequence of the delay in the planned Cerro Oro drill program, Miranda has advised Prism that their obligations under the joint venture agreement are now satisfied, and that Prism may terminate the agreement with no monetary consequence. Miranda is pleased to have had Prism as a partner at Cerro Oro, and both companies will continue to consider partnering other Miranda projects in Colombia. Miranda will look for another funding partner on the project.
Miranda drilling demonstrated a proof of exploration target concept, and encountered significant multi-stage, telescoped primary epithermal and possible secondary porphyry-style alteration. This alteration and mineralization complexity was not recognized previous to core drilling. The geometry of the “Victoria Vein” and other veins and vein-breccia were defined, which will help design follow up drilling.
As a consequence of the delay in the planned Cerro Oro drill program, Miranda has advised Prism that their obligations under the joint venture agreement are now satisfied, and that Prism may terminate the agreement with no monetary consequence. Miranda is pleased to have had Prism as a partner at Cerro Oro, and both companies will continue to consider partnering other Miranda projects in Colombia. Miranda will look for another funding partner on the project.
Miranda drilling demonstrated a proof of exploration target concept, and encountered significant multi-stage, telescoped primary epithermal and possible secondary porphyry-style alteration. This alteration and mineralization complexity was not recognized previous to core drilling. The geometry of the “Victoria Vein” and other veins and vein-breccia were defined, which will help design follow up drilling.
These drill results show a strike extent of 130 m along the “Victoria” fault-breccia-vein zone extending from the surface to a depth of 80m. Gold mineralization is strongly correlated with mercury (to 9.6 ppm), antimony (to 139 ppm), arsenic (to 1900 ppm) and zinc (to 4740 ppm). No other elements show appreciable elevated values.
In conventional zoning models for epithermal systems, high level to low level elemental occurrences are – Mercury ? Antimony ?Arsenic ? Gold. In the same zoning models, gold is typically minor or absent in the mercury zone and gold begins to occur more strongly at the deepest extent of antimony, and the highest gold grades occur where arsenic begins to diminish as a major element. Zinc is associated with gold in many South American epithermal deposits, and the gold-zinc association at Cerro Oro compares favorably to the same relationship seen at nearby Marmato. Using the same exploration zoning model, Marmato would occur with similar abundant zinc and adularia, but below the zone of mercury-antimony observed at Cerro Oro.
All five plus-1g Au/t intercepts contained either banded quartz vein or vein-breccia over 1m or greater. The minus-1g Au/t intercepts contained pyritic stockwork or sheeted pyritic veinlets and disseminated pyrite. Fine-grained adularia is associated with all gold occurrences. Some breccias contain matrix supported, mineralized clasts that may be explosively injected from lower depths. Breccias are from 6 m to 20 m wide, although the significant gold intervals within them are narrower. However in CO-001, 14.7 m of mixed banded vein and vein-breccia are significantly mineralized.
Alteration is typified by abundant mixed clays and more local silicification. In core, up to four cross-cutting events are observed. Adularia has two habits of occurrence – both as vein and veinlet selvages or pervasive within other alteration.
This limited drill program tests 130m of a system that has a mapped 1.5km strike and 600m width. Miranda believes that intercepting multiple mineralized zones justifies continued drill tests of the large epithermal gold system at Cerro Oro. Widely used epithermal zoning models suggest higher gold grades are highly permissible below a near surface zone one of high mercury and antimony.
Miranda intends to do gridded auger soils over the entire alteration zone and where possible determine clay species in soil pits, surface exposures and existing drill core. Gridded soils should indicate the centers of stronger and more continuous areas of gold mineralization. Areas of high-temperature illite may indicate upwelling fluid centers above high-grade mineralization. After modeling structural-dilational controls, future drilling will be designed to test below the mercury-antimony zone.
