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El Pavon
The El Pavon low-sulphidation epithermal gold system --originally known as Natividad- was discovered in 2003 by Radius's geologists close to the town of Waslala, a 5 hour drive from Managua in central Nicaragua. The vein system outcrops on a main road and access to most parts of the project area is possible by foot or on horse back. It is located in a hilly agricultural region largely given over to cattle grazing. The original forest cover has been cut down over many years by slash and burn farmers.
Initial prospecting and trenching returned excellent results - up to 34g/t Au over 4.9m - and El Pavon developed rapidly into one of Radius's key projects.
In 2004, the project was joint ventured to Meridian Gold who funded a major drilling campaign which commenced in late March 2005, with first results published in late July 2005. Meridian tested the most promising gold-bearing structures. The result of their drilling was the definition of a modest historic gold resource, of roughly 340,000oz to 350,000oz of gold contained within roughly 900,000 to 1,000,000 tonnes of mineralized quartz vein. The reader is cautioned that this resource is not compliant with NI43-101, Radius has not yet completed the work required to verify this resource and it cannot be relied upon.
The El Pavon veins are classic examples of the low-sulphidation epithermal type of gold deposit, hosted by two principal rock types, dacite porphyry and moderately welded andesitic ignimbrite flowsis located within a region defined as the "Central Province" of Nicaragua.
Geology
The El Pavon low sulphidation epithermal veins were emplaced within an interbedded, bimodal basaltic andesite-rhyodacite sequence, which has been intruded by domes, dikes and stocks ranging in composition from rhyolite to gabbro. Gold-silver mineralization is hosted within vein, stockwork and breccia zones, with textures typical of formation in the low sulfidation epithermal environment. Many of the veins display multiple stages of both quartz deposition and tectonic and/or hydrothermal brecciation. In fact, brecciated vein zones are far more common than massive fissure veins in the Pavon area.
Mapping defined 3 main zones of veins -Pavon North, Central and South- with at least half a dozen major veins or float trends, totalling many kilometres of strike length of mineralized structures. Meridian's work expanded on Radius' and outlined additional significant structures on the property including (see map):
- Pavon North
- Pavon Central/South
- Ahumada
- Las Brisas
- Manceras
- Astrid
- Las Valles
- Jinji
- Babaska
Click to Enlarge
The epithermal veins are situated within a regional scale structural corridor defined by sub-parallel NW-SE faults. These structures consist of discrete shear zones up to 3m wide striking generally NW, but on a finer scale consist of structures oriented from NW, NNW and connecting structures oriented at EW to ENE.
Vein quartz ranges widely in texture within veins and between veins. Common quartz textures include granular (locally gray with disseminated pyrite), sugary or massive, banded clear, gray and blue chalcedonic. Coarsely crystalline or massive quartz, cockscomb and cockade textures are less common, suggesting most quartz stages deposited at low temperatures.
Adularia is an important component in the Pavon Norte, Central, Sur and Ahumada Veins, and a lesser component in the Las Brisas Vein. It occurs as millimeter-wide growth rims with banded massive, granular or chalcedonic quartz, and locally as radiating crystal sprays extending up to 1.0 cm into quartz bands. Examination of drill logs shows a general correlation of gold with total vein percent and adularia vein percent. Unfortunately, the presence of adularia does not guarantee gold values over 1.0 g/t, and visual identification of ore grade material in Phase I core holes was not very reliable.
Click to Enlarge
Outcrop of banded quartz-adularia vein above Radius hole PADH-07.
Photograph courtesy J. M. Edwards Corp.
In July 2005, Meridian completed Phase 1 drilling, and they then completed a second phase --an additional 27 holes- in Q3 2006. Over all, the drilling results were disappointing and failed to extend the mineralized shoots intersected Radius's initial trenching. Strong veining with highly favourable textures has been intersected in many drill holes, but results generally failed to exceed 2-5 g/t Au.
The results from the drilling at Pavon Central and Pavon North veins show the most encouragement with a couple of significant intercepts, although here also deeper drilling shows a dramatic decrease in veining and gold grades. The best result in the 2006 drilling from Pavon Central was 30.54 m at 5.84 g/t Au in hole NAT-06-060 from a vein and breccia zone that included seven metres at 11.26 g/t Au, and, at Pavon North, hole NAT-06-067 cut 20.2 m at 3.22 g/t Au, including 4.52 m at 7.25 g/t Au.
Detail of the trenching and drill results can be found in the following press releases:
June 22, 2004: Radius upgrades high-grade trench results from El Pavon, Nicaragua
September 16, 2004: Radius cuts 2.5m grading 57.3 g/t Au at Pavon
April 1, 2005: Drilling underway at El Pavon gold project, Nicaragua
July 25, 2005: Radius releases first Natividad drill results
November 21, 2005 Radius Provides Natividad Update
October 13, 2006: Radius provides Natividad drilling update
Radius' management agree with Meridian Gold's conclusion that a moderate-sized, potentially open-pittable gold resource exists at Pavon.
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