Riscos de Oro Project
Overview Diamond Drilling on Riscos de Oro Project 2011  Borosi Concession Overview - Riscos de Oro To date, 17 drill holes (4,337 metres) of a planned 6,000 metre diamond drill program have been completed with assay results received for 9 holes totaling 2,328 metres. All 9 holes intersected veins or mineralized structures with variable gold and silver grades. The resource delineation drill program has been successful in confirming the continuity of the gold-silver vein system in a 200 metre long data gap between the areas of historic drill testing and the area newly identified by Calibre in the 2010 drill program. To date the resource delineation program has also successfully added an additional 250 metres of confirmed strike length to the vein system northeast and southwest of the previously drilled areas, with gold-silver mineralization now confirmed over a strike length of 725 metres and to a depth of 299 metres. The major resource delineation drill program on the Riscos de Oro deposit is on-going. The program includes:
The Company has received assay results for a 2011 regional soil survey program at Riscos that included over 1,500 soil samples. The results show anomalous gold -- arsenic over a three kilometre strike length coincident with the Riscos de Oro vein trend in the vicinity of the historic deposit. Additional anomalies have been identified extending a further four kilometres of strike length towards the southwest. Areas of anomalous Au-As-Pb-Zn have also been highlighted in the El Paraiso area and at the Central Zone. Based on the success of the soil survey, the Company has commenced a trenching program along the trend of the inferred vein system to further investigate the strong Au-As anomalies identified. Combined results from soil samples and trenches will be used to plan reconnaissance drill holes along the seven kilometre structure that hosts the Riscos de Oro deposit. The following slides provide a drill-hole plan and gold in soil anomaly maps. Highlights of the Phase II Resource Delineation drill results include;
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Phase I and II Drilling Results Beginning in late 2009, Calibre completed reconnaissance geological mapping over a 20 square kilometer area, excavated 87 metres of trenches and collected 106 surface rock and 1393 soil samples. In 2010 and 2011, 4,600 metres of diamond drilling in 18 holes was completed by Calibre at Riscos de Oro. The historically defined ore shoot at Riscos de Oro was only mined to an approximate depth of 93 metres below surface and along strike for 300 metres. The initial drill program in 2010 focused on testing the down dip extension of the known mineralization and tested for an additional possible ore shoot along strike of the main workings towards the northeast. Over the course of the initial program, Calibre was able to extend the historically exploited ore shoot to a depth of over 280 metres, highlighted by intercepts of 11.50 g/t gold and 72.30 g/t silver over 2.30 metres (RD10-003) and 2.44 g/t gold and 292.60 g/t silver over 5.80 metres (RD10-001). As part of the same program, drill-hole RD10-005 was collared approximately 300 metres along strike and to the northeast of hole RD10-001. RD10-005 intercepted 9.04 g/t gold and 30.02 g/t silver over 4.14 metres. This hole was noteworthy as it confirmed that Riscos de Oro is a robust gold-silver target with numerous mineralized ore shoots that can be traced on surface and to depth below shallow historic workings. This hole was followed up by RD10-009 which intercepted 4.23 g/t gold and 384.86 g/t silver over 8.53 metres. The 2011 drilling program was designed to follow up on the multiple high grade gold and silver intercepts from 2010. The 2011 program was extremely successful with all 8 holes drilled intersecting significant widths and grades of gold-silver mineralization further confirming the extensive and robust nature of this precious metal epithermal system. In addition, economically significant parallel epithermal veins were encountered beneath the historically defined veins significantly adding to the potential of the system. The 2011 program was highlighted by drill-hole RD11-010 which intercepted 10.25 g/t gold and 288.25 g/t silver over 5.40 metres and RD11-017 which intercepted 9.31 g/t gold and 336.06 g/t silver over 3.90 metres. Click to Enlarge
The deposit remains open in all directions and the Company is planning an expanded program of infill and step out drilling in order to define the full extent of this impressive gold-silver system. The program is slated to begin in the second half of 2011. Highlights of the assay results for the completed programs in 2010 and 2011 are compiled below.
Click here to view complete assay results for the completed programs in 2010 and 2011 in PDF Format
Geology Historically defined mineralization occurs within a single epithermal quartz vein zone that ranges from 7 to 11 metres thick in underground workings, strikes 053o and dips 60o towards the northwest. The vein is commonly of low sulphide content (~3%) but can locally contain up to 10% sulphides. The observed sulphide assemblage includes pyrite, chalcopyrite, sphalerite, galena and argentite. The low-sulphidation epithermal veins encountered in the northeastern part of the Borosi concessions (of which Riscos de Oro is included) are similar in many respects to the epithermal veins of the >2.6 million ounce Bonanza gold-mine district, located 35 kilometres to the west. The areas of defined veining in each camp are roughly similar in size (12 x 14 km for the northeast Borosi concessions; 7 x 20 km for Bonanza), both are hosted by Cretaceous to mid-Tertiary Matagalpa and pre-Matagalpa Formation andesitic volcanic rocks, the majority of veining strikes NE-SW and dips steeply towards the northwest and the veins appear related to Tertiary extension in northeastern Nicaragua. Topographic relief in the Bonanza camp is significant and therefore delineation of epithermal veins is easier than on the Borosi concessions were the topography is more subdued. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
