Orosur Mining Inc. Announces
Exploration and Development Update
SANTIAGO, Chile, August 15, 2012 � Orosur Mining Inc. (the "Company") (TSX: OMI) (LSE: OMI) a South American-focused gold producer and explorer, announces updates on its major exploration projects in Uruguay and Chile.
David Fowler, Chief Executive Officer commented:
�Good progress has been made on Mahoma and Pantanillo during the quarter. At Mahoma drilling has confirmed the potential to delineate a high grade ore source that could extend the mine life at San Gregorio. A further 4,500 meters of drilling is planned for calendar 2012 to define a NI 43-101 resource. At Pantanillo drilling confirmed the potential for additional oxide resources and our preliminary economic assessment demonstrated the potential for Pantanillo to develop into a production asset.�
Key Developments
- A 3,016 meter drill program at Mahoma confirms the potential for high grade narrow vein mineralization. A follow-up drilling program of approximately 4,500 meters is planned to commence in September 2012 to enable a NI 43-101 resource to be defined in calendar 2012 with a goal of providing the basis for a feasibility study during the first half of calendar 2013.
- Preliminary Economic Assessment of the Pantanillo project released in May 2012 showed a net present value before income tax of $US 50 million at an 8% discount rate and an IRR of 19 percent at a $US 1,250 gold price.
- New mineralized breccia zone drilled at Pantanillo Central approximately 2 km from the existing resource confirms potential to add to oxide resources at Pantanillo. Drill hole PCEN-12-005 returned an encouraging intercept of 19 meters at 0.73 g/t Au.
- Follow-up field work on new target at Anillo expected to commence in September 2012.
- Talca drilling intercepts high grade mineralization in Sector Sur including 2 meters at 47.2 g/t in drill hole TALCA12-43DDH.
- Mr Walter Muelebach was appointed General Manager Exploration on 1 July 2012.
Uruguay Projects
San Gregorio
A drilling program, comprising 4,553 meters of reverse circulation (�RC�) and Diamond drilling, was completed during the 2012 fiscal year at San Gregorio in order to update the geologic model and better define the resource for the San Gregorio deposit.
OMI completed a 1,523 meter resource definition drill program at the Vaca Muerta project located approximately 85km east (by existing roads) of the San Gregorio plant. Surface work in the Isla Cristalina belt near the San Gregorio operation during 2012 has identified targets at Santa Barbara, Santa Ernestina, Peru/ Esperanza and Arenal East.
Final resources and reserves numbers are expected to be released in September 2012.
Mahoma
The Mahoma Project area contains four principal gold bearing quartz veins that were previously mined via shallow open pits within granodiorite host rocks. The granodiorite stock measures approximately 3 km wide in the Mahoma area and contains additional quartz veins that have not yet been explored. The area is located approximately 130 kilometres from Montevideo and 405 kilometres from the San Gregorio mine, into the Florida Greenstone belt.
Four principal veins have been identified; veins I, II, IIB and IV. Vein II is the longest and most consistent that has been historically drilled and mined. It has a drilled strike length of 900 metres and a shallow open pit extends along 450 metres of its strike length. A second portion of vein II is approximately 1,200 metres to the east of the main mineralized lens and it has been drilled for over 700 metres along strike with 220 metres showing continuous mineralization.
Only the upper portions of the four drill hole defined veins have previously been mined and there is significant exploration upside potential to define more veins and extend the known veins down dip.
Orosur has held the property since 2009, however issues with land access had previously prevented exploration. During the second half of 2011 these issues were resolved and exploration is now being conducted.
The Mahoma Project, previously operated by American Resource Corporation, produced 16,419 ounces (73,431 tonnes at 6.98 g/t Au with 91.6 per cent recovery) between 1993 and 1997. A pre-mining non -compliant NI 43-101 probable reserve of 281,000 tonnes at a diluted grade of 9.36 g/t (15 per cent dilution assumed) was estimated by Watts, Griffis and McOuat.
During the second half of fiscal 2011/12 the Company completed 38 drill holes for a total of 3,016 meters, comprising 588 meters of RC pre-collars and 2428 metres of Diamond drilling. The drill programme was designed to generally confirm historical drill results for vein I, vein II and vein IIB. New drill results are shown in table 1 with previously reported results shown in table 2.
To read the complete news release, please see the following link:
http://www.orosur.ca/_resources/news/nr_2012_08_15b.pdf