Orosur Mining Inc. Announces Update on Explorat...

Orosur Mining Inc. Announces Update on Exploration Activities in Chile

Orosur Mining

Orosur Mining Inc (“OMI”, ‘Orosur’ or the ‘Company’) (TSX: OMI) (AIM: OMI), the South American focused gold explorer and producer, today provides an update on exploration activities undertaken at its key Chilean prospects, Anillo and Pantanillo.

Highlights:

• Anillo – successful completion of CSAMT (Controlled Source Audio-frequency Magneto Telluric) survey, to pinpoint the location of sub-vertical silica-bearing structures which may host economic gold-silver mineralization. The Company will commence drill testing the highest priority targets in May, 2013.
• Pantanillo - new geological mapping and sampling has confirmed the evidence of a high sulfidation gold system under a steam heated zone at Quebrada Pantanillo. Additional activities over the last 6 months have been focused on the evaluation of new, potentially higher grade, exploration targets that lie outside of the existing mineral resource. This potential high sulfidation gold system is located approximately 4 kilometres East-Southeast of Pantanillo Norte where the Company has defined a maiden National Instrument 43-101 measured and indicated mineral resource of 47 million tonnes at 0.69 grams of gold per tonne for 1.05 Million ounces of gold. The Company is currently evaluating next summer campaign including geophysics and drilling at the new areas starting in November 2013.

Tony Shearer, OMI’s Chairman, commented: “We are very pleased with the results of the CSMAT geophysics which have identified high priority drill targets at Anillo which we plan to start drilling in May. At the same time, the re-evaluation of Quebrada Pantanillo as a high sulfidation gold system is an encouraging step in improving the economics of the Pantanillo project.”

Anillo Prospect, Region II (OMI earning up to 65% Interest)

The Anillo prospect is located 150 kilometers southeast of Antofagasta, at an average altitude of 1,900 metres above sea level, between Yamana Gold’s El Peñon gold-silver mine (which in 2012 produced 462,000 gold equivalent ounces (“GEO”) at cash costs of $US 440 per GEO) and the Pampa Augusta Victoria gold-silver discovery.

OMI’s exploration activities to-date have focused on the discovery of high grade epithermal (El Peñon-type) gold-silver mineralization in the western part of the property. The definition of drill targets at Anillo through a combination of geological mapping, trenching, and geophysics has been completed, with drill testing of the highest priority targets scheduled for May, 2013.

A map of Anillo is accessible at: http://www.orosur.ca/exploration_chile/anillo/

Recent exploration activities completed at Anillo have confirmed the presence of anomalous gold and silver values associated with the shallow, weakly mineralized portions of an epithermal vein system. Geophysical contractor Zonge has completed a CSAMT survey, the primary goal of which is to pinpoint the location of the sub-vertical silica-bearing structures which may host economic gold-silver mineralization. A total of 19 line kilometers of CSAMT in 14 lines have been completed. The CSAMT geophysical method has been a highly valuable technique in the discovery of El Peñon and other epithermal vein systems worldwide.

During May, 2013, an initial 10 holes (3,000 meters) of Reverse Circulation Drilling will be initiated to test the highest priority targets for gold and base metals on the Anillo property.

OMI’s Chilean subsidiary Fortune Valley signed an earn-in agreement for Anillo with Chilean state entity CODELCO in September, 2009, which gave OMI the right to earn-in to a 65% interest in the prospect in return for completing i) $US 3 million of staged exploration expenditures before September, 2013, and ii) the completion of an economic study by September, 2015. As of the third anniversary of the agreement (August 31, 2012), OMI had completed expenditures of $US 2.49 million at Anillo. The Company anticipates that the programme planned for May 2013 will take the Company over the $US 3 million mark.

Pantanillo Prospect, Region III (100% OMI)

Pantanillo is located 100 kilometers east of Copiapó in the prolific Maricunga belt of Chile’s Region III.

Field activities over the last 6 months have focused on the evaluation of new, potentially higher grade, exploration targets (e.g. Quebrada Pantanillo) that lie outside of the existing mineral resource. New geological mapping and sampling has confirmed the evidence of a high sulfidation gold system under a steam heated zone at Quebrada Pantanillo. This is close to an historical drill hole DDHQP-02 from Kinross. This hole returned higher gold intercepts (up to 2.9 grams per tonne of gold) than the average occurred at Pantanillo Norte. Pantanillo Norte forms the basis of the existing defined resource. Quebrada Pantanillo is located approx. 4 km to the E-SE of Pantanillo Norte.

The Company is considering further surface mapping, geophysics and drilling in the areas of Quebrada Pantanillo and Oro-52 in order to follow up on the good results obtained from the 2012 drilling campaign.

A map of Pantanillo is accessible at: http://www.orosur.ca/exploration_chile/pantanillo/

On June 1, 2012, OMI announced updated results for a Preliminary Economic Assessment (“PEA”) completed on the Pantanillo Norte gold resource, concluding that positive economics could be derived from a 5 year mine life, combined open pit mining and heap leach operation treating 7 million tonnes ore per annum on the existing resource. The additional exploration has the objective of adding new mineral resources to improve the economics of the project.

Talca Prospect, Region IV (25% OMI, Earning in to a 100% interest)

No significant work has been completed at the Talca project since October 2012, as the Company continues to evaluate alternatives for maximizing returns to OMI shareholders.

Qualified Person's Statement

The information presented in this press release has been reviewed by Walter Muehlebach, GM Exploration of OMI and is considered to be in compliance with NI 43-101 reporting guidelines. Mr Muehlebach is a graduate in Geology of the Universidad Católica del Norte (Chile) and a member of the Chilean Comisión Calificadora de Competencias en Recursos y Reservas Mineras, and has 23 years of experience in the field of mineral exploration.

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 (OMI.TO) and London (OMI).

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.

For further information, please contact:
Orosur Mining Inc
Tony Shearer, Chairman, + 44 7961 307 894
[e-mail]
Ignacio Salazar, Interim Managing Director, + 562 2924 6800
[e-mail]
or
Canaccord Genuity Limited (Nominated Adviser & Broker)
Andrew Chubb/Ross Allister, [phone]