Orosur Mining Inc. (?OMI' or ?the Company') (TSX-V:OMI)(AIM: OMI), a South American-focused gold producer and explorer, announces an exploration update for its Chilean and Uruguayan exploration programs.

Highlights

  • Results have been received for approximately 50% of the ongoing Sobresaliente drill program. Best gold intercepts include hole SSRC039 that reported 5 meters at 14.8 g/t Au from 84 meters, including 1m at 64.29 g/t Au and hole SSRC045 that reported 23 meters at 1.64 g/t Au from 157 meters.
  • A first pass drill program of 2,497 meters of reverse circulation drilling was completed at the Anillo project. Anomalous results were reported in two of the five targets tested and this drilling indicated the presence of high level, low temperature epithermal mineralization at shallow depths below surface. Deeper drilling planned for May 2011.
  • OMI has commenced a planned 6,500 meter summer drilling program at the Pantanillo project.

David Fowler, CEO of the Company commented: "The first half of our drill program on the Sobresaliente project has confirmed the existing resources on the project and identified a number of new positive intercepts outside the existing resource such as hole SSRC045 which contained 23 meters at 1.64 g/t Au. The first pass drill program at Anillo tested five targets to a depth of up to 200 meters. Anomalous, low temperature epithermal mineralization at a number of these targets leads us to believe that we may be in the upper portions of the system and that deeper drilling is required. We plan to commence this drilling in May 2011.?

Sobresaliente (Uruguay)

The Sobresaliente project is located 5 km North of the San Gregorio Operation and comprises four discrete orebodies: North, Central, South and East. The mineralization appears to be located at the intersection of two regional structural trends where deformation has produced intense cataclasis and brecciation. Wide zones in excess of 100 m of veined / stock worked granitoids are present and the overall mineralized trend is nearly 1.2 km long.

A combined RC-DD drilling program commenced on 1 December 2010 to infill known mineralization, test along-strike extensions of the known ore bodies, test for the possibility of a bulk tonnage-low grade operation, improve the category of the resource and locally check the geologic and structural model. A total of 6,800 meters (42 holes for a total of 4,855 meters of reverse circulation (?RC?) drilling and 20 holes for a total of 1,945 meters of diamond drilling (?DD?) had been proposed. As of 10 February 2011, 2,295 meters of RC drilling (31 holes) and 1,219.85 meters of DD (14 of 20 holes) have been completed.

Gold results have been completely reported for reverse circulation drill holes and partially for diamond drill holes. In general, values have confirmed existing grades in the main ore bodies. Significant additional mineralization corresponding to narrow ore shoots is being intercepted on the north and northwest extension (~100m along-strike) of the Central Zone. A significant intercept, that finished in mineralization, of 23 meters at 1.64 g/t Au from 157 meters has also been reported down dip on the eastern zone.

Complete gold results reported until 14 February 2011 are presented in the following tables, where the drill holes are sorted by the ore body zones:

Zone   Hole (1)   From (m)   Intercept (m @ g/t)   Notes
         
Central SSRC022 75 2 @ 0.62  
Central SSRC023 20 6 @ 1.97 incl. 1m @ 7.50 g/t
Central SSRC024     No significant results
Central SSRC025 0 4 @ 1.53 incl. 1m @ 3.64 g/t
Central SSRC025 6 2 @ 0.63  
Central SSRC025 13 2 @ 0.68  
Central SSRC025 19 6 @ 0.64  
Central SSRC025 33 1 @ 1.07  
Central SSRC025 60 1 @ 2.77  
Central SSRC029 20 2 @ 1.32  
Central SSRC029 28 4 @ 2.90 incl. 1m @ 4.43 g/t
Central SSRC029 28   incl. 1m @ 4.73 g/t
Central SSRC029 42 2 @ 1.12  
Central SSRC030 7 2 @ 0.93  
Central SSRC030 25 3 @ 0.54  
Central SSRC030 122 5 @ 0.79  
Central SSRC030 153 5 @ 0.53  
Central SSRC030 169 4 @ 0.68  
Central SSRC031 71 1 @ 1.06  
Central SSRC032 0 1 @ 2.46  
Central SSRC033 29 1 @ 0.80  
Central SSRC034     No significant results
Central SSRC035 11 7 @ 0.45  
Central SSRC035 61 4 @ 1.90 incl. 1m @ 4.05 g/t
Central SSRC035 122 4 @ 2.74 incl. 2m @ 4.53 g/t
Central SSRC035 132 2 @ 0.52  
Central SSRC035 149 1 @ 3.29  
Central SSRC039 27 2 @ 0.64  
Central SSRC039 47 1 @ 1.37  
Central SSRC039 66 4 @ 3.52 incl. 2m @ 6.55 g/t
Central SSRC039 84 5 @ 14.80 incl. 1m @ 6.87 g/t
Central SSRC039 84   incl. 1m @ 64.29 g/t
Central SSRC039 129 2 @ 2.08 incl. 1m @ 3.43 g/t
Central SSRC040 61 2 @ 4.22  
Central SSRC041 43 1 @ 0.69  
Central SSRC042 22 2 @ 1.38  
Central SSRC042 35 6 @ 4.19 incl. 1m @ 21.73 g/t
Central SSRC042 46 1 @ 2.27  
Central SSRC043 41 1 @ 0.98  
Central SSRC043 44 2 @ 1.32  
Central SSRC044 0 1 @ 2.35  
Central SSRC044 10 3 @ 0.82  
Central SSRC044 28 2 @ 0.57  
East SSRC016 33 2 @ 1.28  
East SSRC016 40 3 @ 0.57  
East SSRC016 59 4 @ 1.92 incl. 1m @ 3.86 g/t
East SSRC017 23 3 @ 0.83  
East SSRC017 36 4 @ 1.19  
East SSRC019 50 1 @ 1.82  
East SSRC045 4 3 @ 1.44  
East SSRC045 157 23 @ 1.64 incl. 1m @ 4.02 g/t
East SSRC045 157   incl. 1m @ 3.34 g/t
East SSRC045 157   incl. 1m @ 4.08 g/t
North SSRC018     No significant results
North SSRC020 3 1 @ 1.29  
North SSRC020 7 1 @ 1.61  
North SSRC021     No significant results
North SSRC036 131 3 @ 0.72  
North SSRC037 49 3 @ 0.92  
North SSRC037 121 4 @ 0.82  
North SSRC037 128 2 @ 0.49  
North SSRC037 132 7 @ 0.88  
North SSRC037 141 2 @ 0.65  
North SSRC038 86 3 @ 0.48  
North SSRC038 102 1 @ 0.90  
North SSRC038 111 3 @ 2.49 incl. 1m @ 4.42 g/t
North SSRC046 75 3 @ 0.55  
North SSRC046 86 4 @ 0.45  
North SSRC046 140 1 @ 2.93  
South SSRC026 21 1 @ 3.06  
South SSRC027 7 1 @ 1.06  
South SSRC027 21 4 @ 1.92 incl. 1m @ 5.20 g/t
South SSRC027 27 1 @ 2.13  
South SSRC027 34 5 @ 0.62  
South SSRC028     No significant results
Central SSDD007 0 12 @ 2.76 incl. 4m @ 6.90 g/t
Central SSDD007 17 3.65 @ 1.74 incl 0.5m @ 9.00 g/t
Central SSDD007 24 1.30 @ 0.84  
Central SSDD017 19 6.1 @ 0.56  
Central SSDD018 16,2 2.4 @ 2.07  
Central SSDD018 21,8 7.7 @ 0.55  
Central SSDD018 79,2 1.7 @ 2.01  
Central SSDD019 28 7.3 @ 0.63  
Central SSDD019 38,25 7.5 @ 2.10 incl 0.75m @ 4.19 g/t
Central SSDD019 38,25   incl 1m @ 7.33 g/t
Central SSDD019 57 2 @ 0.55  
Central SSDD019 71,8 3.9 @ 0.63  
East SSDD012 33,1 1.6 @ 0.98  
East SSDD012 37,3 2.6 @ 1.58  
East SSDD012 41,7 5 @ 0.90  
East SSDD012 75,7 4.9 @ 0.51  
North SSDD009 9 7 @ 0.63  
North SSDD010 28 6.4 @ 0.97  
North SSDD010 54,9 2.50 @ 1.05  
North SSDD010 81,45 2.00 @ 0.58  
North SSDD011 26,4 1.6 @ 1.76  
North SSDD011 51,3 0.9 @ 1.27  
North SSDD011 59,2 5.6 @ 0.48  
North SSDD013 103,4 3.3 @ 0.57  
North SSDD014     Results pending
South SSDD008 52,25 1.60 @ 0.53  
South SSDD008 77 2 @ 0.97  
South SSDD008 81 4.50 @ 2.05 incl 0.5m @ 14.76 g/t
South SSDD015     Results pending
South SSDD016     Results pending
 
Notes

Weighted intercept grades were calculated using an external cutoff of 0.4g/t Au and up to 2 meters of internal dilution is reported. Samples were processed using OMI's in house laboratory using fire assay with atomic absorption finish. For quality control purposes 5% of samples are re-analyzed at external laboratories.

The best intercepts reported correspond mainly to the Central Zone (5m at 14.8 g/t including 1m at 64.29g/t) and East Zone (23m at 1.64 g/t). The drilling program will continue during February. The objective is to produce a new resource estimation that is NI43-101 compliant by Mid 2011.

Anillo (Chile)

OMI completed a first pass drill campaign of 16 reverse circulation drill holes for a total of 2,497 meters at the Anillo project. The drilling targeted anomalous geochemistry in rock and trench sampling combined with magnetic and VLF anomalies from geophysical surveys completed in October 2010.

Anomalous Ag and Au values (maximum 0.37 ppm for Au and 6 ppm for Ag) were intercepted over several meters in holes drilled in two different sectors located to the north and east of Yamana's neighboring Pampa Victoria discovery. Drilling confirms the presence of high level, low temperature epithermal mineralization at shallow depths below surface.

The Company is planning a follow up drill campaign including several deep holes (up to 500m depth) drilled in fences to test for mineralized N/S oriented structures. This decision is based on the knowledge that epithermal orebodies in the district are characteristically deep and often blind with only weak surface manifestations.

Two new sectors (central and west) at the Anillo project are currently being mapped in detail, and high density surface geochemistry is underway. Ground magnetic surveys also continue. The company hopes to generate new targets for first pass drilling in combination with the drilling mentioned above, during May 2011

Pantanillo (Chile)

OMI commenced a planned 6,500 meter summer drilling program at the Pantanillo project in early February 2011.

The first 1000m of (RC) drilling will test for additional oxide resources on the Pantanillo Sur target and will be followed by some 5,000m of reverse circulation and diamond drilling at Pantanillo Norte in late February pending the approval of the DIA which is expected by mid February.

Drilling at Pantanillo Norte will focus on enlarging as well as upgrading the current NI43-101 compliant measured and indicated oxide resource of 1.05M ounces (Sept, 2010). Also, the Company plans to drill several deep diamond holes at Pantanillo Norte to further investigate and better define the underlying sulfide resource and obtain material for metallurgical and geomechanical tests.

Vaca Muerta (Uruguay)

OMI completed a 2,736 meter drill program in December 2010 at the Vaca Muerta project located approximately 85km east (by existing roads) of the San Gregorio plant. Encouraging final assay results where reported in the quarter 2 news release (12 Jan, 2011).

The Company has begun initial metallurgical tests and resource modeling to fast track the project. Additional detailed surface mapping and soil sampling began in January covering the entire Vaca Muerta property. Special attention is being given to the combined 1km strike extensions to the NW and SE of the Vaca Muerta deposit, as well as to the north and south where several reconnaissance geochemical anomalies are known.

Additional drilling planned for March, 2011 will include step-out holes along the Vaca Muerta controlling structure, testing of new geochemical targets and infill drilling to facilitate a measured and indicated NI 43-101 compliant resource estimation.

Other Projects (Uruguay)

OMI continues exploration on several other properties located in southern Uruguay. The Company will start a 1,500 meter infill drill campaign at Crucera in February 2011 and complete a measured and indicated NI43-101 resource estimate by the end of fiscal 2011. First pass exploration drilling has also been planned for the Rocha and Texas projects in southern Uruguay. Some 2,000-2,500 meters has been dedicated to each project and drilling will begin in April 2011.

Qualified Person's Statement

The information presented in this press release has been reviewed by William F. Lindqvist, a director of OMI. Dr. Lindqvist holds a Ph.D. in Applied Geology from Imperial College, London, has been a member of the AusIMM for 46 years, and has had 40 years of experience in international minerals exploration and property evaluation.

Forward-Looking Statements

All statements, other than statements of historical fact, contained or incorporated by reference in this news release, including any information as to the future financial or operating performance of the Company, constitute "forward-looking statements" within the meaning of certain securities laws, including the "safe harbour" provisions of the Securities Act (Ontario) and the United States Private Securities Litigation Reform Act of 1995 and are based on expectations estimates and projections as of the date of this news release. There can be no assurance that such statements will prove to be accurate; such statements are subject to significant risks and uncertainties, and actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements include, without limitation success of exploration activities; permitting time lines; the failure of plant; equipment or processes to operate as anticipated; accidents; labour disputes; requirements for additional capital title disputes or claims and limitations on insurance coverage. The Company disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events and such forward-looking statements, except to the extent required by applicable law.

ENDS

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 Inc
David Fowler, CEO + 598 2601 6354
Ignacio Salazar, CFO + 598 2601 6354
info@orosur.ca
or
Matrix Corporate Capital LLP (Nominated Adviser & Broker)
Louis Castro, +44 (0) 203 206 7209
Tim Graham, +44 (0) 203 206 7206
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Blythe Weigh Communications (Public Relations and Investor Relations)
Tim Blythe: +44 (0) 7816 924626
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