Oroco Commences Phase Two Drilling at Cerro Prieto
Thursday, July 23rd, 2009
Oroco Resource Corp. is pleased to announce the commencement of the 2009 field program on its Cerro Prieto Project in northern Sonora, Mexico.
A drill contract has been signed with Cabo Drilling de Mexico S.A. de C.V. and crews are currently in the field preparing for the arrival of the first of two diamond drill rigs that will be used for the 8,000 meters of drilling planned for Oroco’s Phase Two program at Cerro Prieto. The program is focusing on the expansion, on strike to the north, of the previously defined oxide resource. Cerro Prieto’s indicated resource of 7.45 million tonnes, with an average grade of 1.24 g/t Au, 12.8 g/t Ag, 0.41% Pb and 1.04% Zn using a 0.5 g/t gold cutoff (see news release dated May 11, 2009), was calculated following initial drilling on 600 meters of strike length of the mineralized structure. Phase Two drilling will test approximately 1,500 meters of strike length of the structure, where continuity of the mineralized zone has been established by a step-out drill hole and surface trenching completed during 2008, as well as being strongly indicated by the presence of historic mine workings. This resource is hosted in a near vertical shear zone, which is present from surface to a maximum depth of approximately 350 meters, where it transitions to sulphide mineralization. Oxide mineralization was encountered in all holes drilled in Phase One with the exception of the deepest, which encountered sulphide mineralization at a depth of 400 meters from surface. Following Phase One drilling completed by Oroco during 2008, mineralization remains open at depth as well as on strike to the north and south.
Phase Two drill holes will be centered at 100 meter intervals on the plane of mineralization on the approximately 550 meters of strike length remaining to the north boundary of Oroco’s San Felix concession, and will continue northward at 200 meter intervals for approximately 1,000 meters of strike length on the adjacent concession recently optioned by Oroco from Yamana Gold. Infill drilling at 100 meter intervals will follow as warranted. Twenty-two holes were completed in Phase One, all successfully hitting the targeted mineralized zone, and approximately 40 holes are anticipated to be completed in Phase Two drilling.
Drilling as part of Phase Two will also include a minimum of two holes targeted to test the sulphide zone previously intersected in CP011 (an intersection of 4.2 meters true thickness averaging 0.19 g/t Au, 79.3 g/t Ag, 0.78% Cu, 3.71% Pb and 6.13% Zn contained within 30 metres of true thickness of mineralization) at a depth of 400 meters from surface, and a minimum of two holes under the highly anomalous exposures of the mineralized zone on the Cerro Prieto North property, where sampling of outcropping mineralization yielded individual assays as high as 2.18 g/t Au, 200 g/t Ag, 2.26% Pb, and 3.17% Zn.
It is anticipated that Phase Two drilling will be completed in approximately four months.
The location of Phase One drill holes as well as the area targeted in Phase Two drilling may be found at the Oroco website at http://www.orocoresourcecorp.com/projects-Cerro-Prieto-Project-Maps-and-Sections.html
Initial metallurgical testing incorporating bottle roll leach tests were successful in extracting up to 91.5% of the contained gold over a 96 hour period (see News Release dated May 11, 2009). Concurrent with Phase Two drilling Oroco will provide coarser samples of ore to be tested by the column leach method in order to determine an optimized metallurgical recovery process. Metallurgical testing is being supervised by consultant, A. H. Winckers & Associates Inc.
The company is working towards having an updated resource calculation along with the next phase of metallurgical testing completed by the end of 2009.