Orosur Mining Regulatory News (OMI)

12 Apr 2012 07:02

Orosur Mining Inc. ("OMI" or "the Company") (TSX VENTURE: OMI) (LSE: OMI), a South American-focused gold producer and explorer, today announces drill results from its 100 per cent owned Mahoma Project in Uruguay. The drilling programme is designed to confirm grades and widths found historically at Mahoma.

Current drilling campaign confirms similar narrow high grade gold results on Veta II as per historical drilling. Drill program to be expanded to target the definition of a NI 43-101 compliant resource during calendar 2012 with the goal of providing the basis for a feasibility study to target annual mine production of 25,000 ounces of gold that could be processed at the San Gregorio mine.

David Fowler, CEO of the Company, stated, "We are pleased with drill results from our first pass drill program at Mahoma as they have confirmed historically identified grades and widths on Veta II. Orosur will now expand its drilling programme with the objective of defining a resource during calendar 2012. It is anticipated that this resource will provide the basis for a feasibility study to produce a total of 25,000 ounces per annum. The study will be based on ore being transported to the San Gregorio mine to minimise capital expenditure and reduce study and permitting time."

The Company has completed 24 drill holes for 1,815 meters from an initial planned drill programme of approximately 3,000 meters, comprising 2,000 metres of RC pre-collars and 1,000 metres of diamond drilling. The drill programme is designed to generally confirm historical drill results for vein I, vein II and vein IIB. This work is expected to be followed by infill drilling to target an initial measured and indicated resource of 250,000 tonnes.

Table 1. Drill-Hole Results for the Mahoma Project, Uruguay
Target								Drill Hole No								From								To								Interval								Interval g/t Au
VETA II ESTE								MHDD001								No significant results
VETA II ESTE								MHDD002								No significant results
VETA II ESTE								MHDD003								42.30								42.75								0.45								21.86
																60.75								61.15								0.40								14.38
VETA II ESTE								MHDD004								No significant results
VETA II ESTE								MHDD005								85.40								85.70								0.30								56.17
																85.70								86.03								0.33								1.40
																87.53								88.25								0.72								2.00
VETA II ESTE								MHDD006								84.95								85.50								0.55								5.33
																86.70								87.20								0.50								2.45
																88.30								88.62								0.32								46.60
																88.62								88.93								0.31								29.30
																88.93								89.43								0.50								1.13
VETA II ESTE								MHDD007								82.55								82.95								0.40								7.97
																85.55								86.60								1.05								2.83
VETA II ESTE								MHDD008								80.45								80.90								0.45								3.47
VETA II ESTE								MHDD009								71.30								71.75								0.45								41.05
																72.20								72.60								.40								5.67
																73.00								73.50								0.50								3.43
																73.80								74.20								0.40								100.63
																74.60								75.00								0.40								6.10
																75.00								75.40								0.40								3.16
																81.30								81.80								0.50								3.11
VETA II ESTE								MHDD010								83.95								84.35								0.40								5.30
																85.85								86.30								0.45								3.46
VETA II ESTE								MHDD015								83.90								84.40								0.50								19.57
																84.40								85.15								0.75								4.79
																86.65								87.15								0.50								12.23
VETA II ESTE								MHRC001								28.00								29.00								1.00								10.86
																43.00								44.00								1.00								15.20
VETA II ESTE								MHRC002								6.00								7.00								1.00								2.10
VETA II ESTE								MHRC003								No significant results
VETA II OESTE								MHDD022								No significant results
VETA II OESTE								MHDD023								No significant results
VETA II OESTE								MHDD025								57.80								58.30								0.50								2.67
VETA II OESTE								MHRC008								No significant results
VETA II OESTE								MHRC009								No significant results
VETA II OESTE								MHRC010								42.00								43.00								1.00								4.25
																43.00								44.00								1.00								14.13
																44.00								45.00								1.00								2.13
VETA IIB								MHDD018								No significant results
VETA IIB								MHDD019								No significant results
VETA IIB								MHRC004								No significant results
VETA IIB								MHRC005								No significant results

A drill hole plan map and sections are available on the Company's website.

Diamond drill holes 1 to 10 and 15 and reverse circulation drill holes 1 to 3 were all drilled within the historically defined 600 meter main portion of the II vein. Diamond drill holes 1 and 2 confirm previous drilling that showed no significant mineralisation on the sections and to depths drilled. Short intervals were assayed to understand grade distribution. While many of the intercepts are narrow the current drilling supports the envisaged target of 9-10 g/t Au over a minable width of 1.5 meters.

Drilling on Veta II Oeste and Veta IIB has not confirmed mineralisation identified in a number of historic sections with results less consistent than expected.

Table 2. Drill Hole Location Data, Mahoma Project, Uruguay
Drill Hole No								East_GK								North_GK								RL								Azimuth								Dip								Depth
MHRC003								401915								6219796								91.5								175								-50								40
MHRC002								402064								6219819								88								175								-55								30
MHDD015								402208								6219880								87								175								-65								110
MHDD010								402337								6219899								82								175								-60								96
MHDD009								402360								6219902								81								175								-60								89
MHDD008								402382								6219903								81								175								-60								85
MHDD007								402408								6219908								80								175								-60								91
MHDD006								402436								6219910								80								175								-60								96
MHDD005								402457								6219909								78								175								-60								93
MHDD004								402483								6219911								78								175								-60								81
MHDD003								402507								6219912								77								175								-55								66
MHRC001								402532								6219900								77								175								-60								60
MHDD002								402582								6219923								76								175								-60								110
MHDD001								402631								6219927								75								175								-50								78
MHDD025								401316								6219756								101.5								175								-55								70
MHRC008								401366								6219760								101								175								-60								70
MHDD022								401439								6219787								101								175								-50								76
MHDD023								401464								6219784								100								175								-50								68
MHRC010								401489								6219791								99								175								-50								60
MHRC009								401517								6219773								100								175								-45								70
MHRC005								401741								6219538								97								175								-45								45
MHRC004								401893								6219553								99								185								-55								70
MHDD019								402044								6219550								99								185								-55								80
MHDD018								402116								6219552								98								175								-55								79
																																																1,815

About Mahoma

The 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 in 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. The main portion of Vein II is sub vertical and the average true thickness is around 1.7 metres. 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 of strike with 220 metres showing continuous mineralization. The width of the second vein varies from 0.2 metres to 3.2 metres with an average width of approximately 1.9 metres.

Vein IIB, 300 metres to the south of vein II, is approximately 550 metres in length and exhibits an average width of 1.5 metres. Vein IV is a thicker quartz vein zone than the other zones but also has a lower grade and a shorter strike length of approximately 250 metres. It has been drilled to only 30 metres from the surface. Vein I comprises a series of short and narrow veins with the average width of these veins being 20 centimetres and the largest vein having a strike length of 100 metres.

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.

Assaying and Qualified Person

Project geologists log and mark the core then technicians cut the individual lengths with a diamond saw, tag the sample bags and secure them with security clips. The samples are then transported to the Company's laboratory facility at San Gregorio. They are dried and crushed to -2mm. A 1,000 gram split of the coarse material is then pulverized to -200 mesh. The rejects remained at the prep facility and the pulps are analyzed for gold by 30g fire assay with an AA/gravimetric finish. In addition, a 214 element ICP analysis is conducted on selective samples. A QA/QC program has been implemented as part of the sampling procedure for the drill program. One standard, one blank or one duplicate are inserted per group of ten samples sent to the laboratory. The information in this news release has been approved by William Lindqvist, the Company's Qualified Person under National Instrument 43-101 standards.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

About Orosur Mining Inc.

Orosur Mining Inc. is a fully integrated gold producer and exploration company focused on identifying and developing gold projects in Latin America. The Company operates the only producing gold mine in Uruguay (San Gregorio), and has assembled an exploration portfolio of high quality assets in Uruguay and Chile. The Company is quoted in Canada (TSX-Venture Exchange: OMI) and London (AIM: OMI).

Orosur Mining IncDavid Fowler, CEOorIgnacio Salazar, + 56 2 9246800CFOinfo@orosur.caorCanaccord Genuity Limited (Nominated Adviser & Broker)Rob Collins, +44 (0) 20 7050 6500orBlythe Weigh Communications (Investor Relations)Tim Blythe, +44 (0) 7816 924626orMatthew Neal, +44 (0) 7917 800011

Copyright Business Wire 2012