Orosur Mining Regulatory News (OMI)

6 Mar 2012 15:15

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 12RC 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 including		Metalera Central		175		180		5m @ 2.70 g/t Au
				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 Number		Sector		East		North		Ag_ppb		As_ppm		Au_ppb		Cu_ppm		Hg_ppb		Pb_ppm
EX75334		Oro 52		498860		6967211		23		2		68		3		79		5
EX75361		Oro 52		498870		6968202		76		7		69		25		2,650		4
EX75362		Oro 52		498868		6968178		397		559		102		2		142		741
EX75366		Oro 52		498879		6967984		2,648		196		146		10		1,507		293
EX75385		Quebrada Pantanillo		497962		6963781		24,389		207		925		15		>50,000		239
EX75386		Quebrada Pantanillo		497988		6963772		27,808		155		129		28		32,125		218
EX75387		Quebrada Pantanillo		497956		6963764		20,442		729		504		47		20,423		766
EX75388		Quebrada Pantanillo		497960		6963754		36,110		225		72		19		21,491		199
EX75437		Pantanillo Central		493529		6962921		4,886		779		597		39		2,984		34
EX75438		Pantanillo Central		493539		6962900		6,648		2,591		580		101		2,363		35
EX75439		Pantanillo Central		493572		6962857		5,222		272		1,646		59		6,507		6
EX75440		Pantanillo Central		493541		6962642		27,858		426		3,054		64		11,272		13

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; info@orosur.ca

Canaccord Genuity Limited (Nominated Adviser & Broker)

+44 (0) 20 7050 6500

Rob Collins

Bhavesh Patel

Blythe Weigh Communications (Investor Relations)

Tim Blythe: +44 (0) 7816 924626

Matthew Neal: +44 (0) 7917 800011

Copyright Business Wire 2012