Orosur Mining update on Chile

 
TIDMOMI 
 
 

Orosur Mining Inc announces initial drilling results in Talca and

Commences drilling at Pantanillo in Chile

SANTIAGO, Chile, March 6, 2012 - Orosur Mining Inc. (the "Company") (TSX VENTURE: OMI) (LSE: OMI) a South American-focused gold producer and explorer, announces results of the drilling campaigns at its projects in Chile: Talca, Pantanillo and Anillo.

Highlights

 
 
    -- Initial assay results from three holes drilled during 2012 at the 

Talca project in Chile have defined 2 meters at 5.7 g/t Au in hole

number Talca 12-23-RC on the Metallera fault and two intercepts of 1

meter at 10 g/t Au in holes Talca 12-29-RC and Talca 12-30-RC in the

southern sector. These results are encouraging and consistent with

expectations for these targets.

 
    -- A 3,000 meter drill campaign has commenced at the Pantanillo project 

in Chile. Three targets will be tested during this programme -

Pantanillo Sur, Oro 52 and Quebrada Pantanilio. Recent sampling and

mapping supports the potential for discovery on these targets and

follows up historical drilling and trenching on these targets by

previous operators.

David Fowler, CEO of the Company commented: "Initial drilling in the southern sector at Talca is encouraging with intercepts confirming the potential for multiple narrow high grade gold mineralization over a potential strike length of 500 meters. This sector and the Metallera central zones which have been significant historical production areas are the focus of current drilling. Drilling has also commenced at the Pantanillo project on three priority targets, Pantanillo Central, Oro 52 and Quebrada Pantanillo. 3,000 meters of RC drilling will target the discovery of new oxide resources. Results of this program are expected to be received in May and June 2012.

Talca - Chile

A second drill campaign at Talca commenced in January 2012. To date, 4,000 meters of RC and diamond holes have been drilled from a planned 7,900 meters in the second campaign, giving a total since drilling began in October 2011 of 8,500 meters combined diamond and RC drilling. An additional diamond rig has been mobilized to the project in order to speed-up drilling and to complete the total planned meters before mid-April 2012.

The second phase of drilling has been focused around the Metalera Central and Sector Sur sheared quartz-veins, both areas with the most intense historical mining activity. Drilling has been planned to delineate the down-dip potential of gold mineralization beneath the historical workings, which extend to a maximum of approximately 100m vertical depth from surface. Significant intercepts from the second phase of drilling to date can be seen in the table below.

 
Hole ID         Sector            From  To   Intercept 
Talca-12-23RC   Metalera Central  175   180  5m @ 2.70 g/t Au 
including 
                                  178   180  2m @ 5.62 g/t Au 
Talca-12-29RC   Delirio           112   113  1m @ 10 g/t Au 
                                  242   244  2m @ 1.15 g/t Au 
                                  247   249  2m @ 1.32 g/t Au 
Talca-12-30RC   Juica W           85    86   1m @ 10 g/t Au 
 
 

The results from drill hole Talca-12-23RC reflect the nature of mineralization along the Metalera Fault with lower grade, 2-3 g/t Au, across the 5-7m wide structure with an increase in grade observed around the footwall contact. This result is encouraging as the intercept is situated approximately 50 meters beneath the extent of the historical workings at this point of the Metalera Fault and mineralization is still open down-dip.

Drillholes Talca-12-29RC and Talca-12-30RC are also encouraging as both holes were drilled as exploration holes testing the potential of the western extension in the Sector Sur sheared vein sets, in this case, the Delirio and Juica veins respectively. The ground across this particular zone has not previously been subject to any historical mining. These intercepts of >10 g/t gold are over 500m west of the intersection between the vein sets and the Metalera Fault system. Assays for other holes drilled in Sector Sur are pending with results expected by the end of March.

The Company's objective is to define the first Inferred NI-43101 resource calculation during calendar 2012.

Pantanillo Chile

Orosur has a measured and indicated resource of 45.9 million tonnes at .69 g/t for 1.023 million contained ounces of gold at the Pantanillo project in the Maricunga belt of Chile. On the 12th of January 2012 the results of a preliminary economic assessment of the project were announced. The major focus of exploration in the 2012 field season which commenced in January 2012 is to identify areas where additional resources can be established to increase potential mine life at Pantanillo before proceeding with the completion of a prefeasibility study on Pantanillo. Three key targets will be the focus of field work at Pantanillo this year, Pantanillo Central, Quebrada Pantanillo and Oro 52. Exploration on these new target areas continued through January and February 2012, with further mapping and rock sampling

The most significant results from the sampling campaign are shown below. Drill targets have been delineated as a result of the surface work with a planned 3,000m RC drilling commencing on 5th March 2012. This exploration drilling campaign is to be executed in tandem with water exploration drilling, which is due to commence on 12th March 2012.

 
Sample    Sector      East    North    Ag_ppb  As_ppm  Au_ppb  Cu_ppm  Hg_ppb   Pb_ppm 
Number 
EX75334   Oro         498860  6967211  23      2       68      3       79       5 
          52 
EX75361   Oro         498870  6968202  76      7       69      25      2,650    4 
          52 
EX75362   Oro         498868  6968178  397     559     102     2       142      741 
          52 
EX75366   Oro         498879  6967984  2,648   196     146     10      1,507    293 
          52 
EX75385   Quebrada    497962  6963781  24,389  207     925     15      >50,000  239 
          Pantanillo 
EX75386   Quebrada    497988  6963772  27,808  155     129     28      32,125   218 
          Pantanillo 
EX75387   Quebrada    497956  6963764  20,442  729     504     47      20,423   766 
          Pantanillo 
EX75388   Quebrada    497960  6963754  36,110  225     72      19      21,491   199 
          Pantanillo 
EX75437   Pantanillo  493529  6962921  4,886   779     597     39      2,984    34 
          Central 
EX75438   Pantanillo  493539  6962900  6,648   2,591   580     101     2,363    35 
          Central 
EX75439   Pantanillo  493572  6962857  5,222   272     1,646   59      6,507    6 
          Central 
EX75440   Pantanillo  493541  6962642  27,858  426     3,054   64      11,272   13 
          Central 
 
 

The rock sample results reflect the differing styles of mineralization that occur within the Pantanillo district. Oro 52 results shows anomalous gold values that are weaker, in comparison to Pantanillo Central and Quebrada Pantanillo, however, the values appear more consistent and are coupled with lower anomalous silver values. The conceptual model for Oro 52 is that of a porphyry system similar to Pantanillo Norte, with lower background anomalies and buried beneath post-mineral superficial cover.

Mineralization at Quebrada Pantanillo visually appears to be a classic hydrothermally altered high-sulphidation system normally observed around the peripheries of porphyry systems. This has now been backed-up by the significant results in the area with high grade silver-mercury and moderate anomalies of gold. A soil sampling campaign will take place along with the exploration drilling at Quebrada Pantanillo, targeting further potential mineralized areas that are highlighted by intense alunite-kaolinte alteration in Aster® imagery. Hypogene alunite alteration is typically observed throughout the whole of the Maricunga belt, associated with advanced argillic alteration caps that overlay gold bearing porphyry-type stockwork systems. Kinross drilled a combined total of 1,235 meter diamond and RC holes in Quebrada Pantanillo during their 2006 and 2007 field campaigns. One hole in particular stands out, DDHQP-02, which intercepted 25.9m @ 0.6 g/t Au, between 98-123.9m depth. More significantly, this drill hole was terminated in mineralization. This drill information together with encouraging rock sample results provide significant encouragement for the potential to make a discovery at Quebrada Pantanillo.

Pantanillo Central exhibits encouraging gold results and moderate to high grade silver and mercury. This high-sulphidation style of mineralization is similar to that observed at Quebrada Pantanillo and together with the high-grade silver results seen in historical trenching done by Anglo-American, justifies the need to drill test this area. The table below shows significant results from some of the trench samples* taken by Anglo-American in the mid-1980s.

 
Trench ID       East_PSAD56  North_PSAD56  Length(m)  Au g/t  Ag g/t 
Road Cutting    493740       6963005,4     7          2,37    8,86 
Trench T2       493754       6963189,19    3          1,00    2,00 
Trench T19      493716       6963207,02    3          1,50    26,00 
Trench T19      493747       6963236,87    6          0,83    5,00 
Trench T19      493757       6963244,72    4          0,93    2,50 
Trench T3       493688       6963267,47    4          0,56    4,50 
Trench T37      493826       6963789,16    5          1,06    9,20 
Trench T37      493833       6963788,88    3          1,23    2,60 
Trench T33      493846       6964275,95    32         0,00    106,20 
Trench T33      493841       6964293,22    10         0,00    34,60 
Trench T5       493851       6964303,19    29         0,00    82,36 
Trench T31      493755       6964311,21    12         0,00    69,50 
Trench T6 (E)   493665       6964301,31    7          1,60    29,80 
 
 

* Taken from Anglo-American data, in which they presented only data above cut-off grades 0.5 g/t Au and/or 30 g/t Ag

Anillo - Chile

Anillo is strategically placed tenement package between Yamana's El Peñon mine and its Pampa Augusta Victoria discovery. A total of 7,173 meters of reverse circulation drilling over two campaigns has been been drilled with a number of anomalous intercepts. Further exploration work has been planned from May 2012, targeting potential NNE strike extension of the El Peñon mineralized structure that appears, from ground magnetic geophysics and selected float sampling, to pass through the western part of Anillo. A programme of detailed mapping and approximately 1,000 meters of trenching will be carried out to further define drill targets.

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).

For further information, please contact:

Orosur Mining Inc

David Fowler, CEO

Ignacio Salazar, CFO + 56 2 9246800; [e-mail]

Canaccord Genuity Limited (Nominated Adviser & Broker)

[phone]

Rob Collins

Bhavesh Patel

Blythe Weigh Communications (Investor Relations)

Tim Blythe: [phone]

Matthew Neal: [phone]