Mariana Resources Ltd Commences Drilling at Las Calandrias Project, Southern Argentina

VANCOUVER, BRITISH COLUMBIA -- (Marketwire) -- 05/22/12 -- Mariana Resources Ltd (TSX: MRY)(AIM: MARL) ('Mariana' or 'the Company'), the AIM and TSX quoted exploration and development company focused on Argentina and Chile, is pleased to announce that a 3,500m diamond drill programme has commenced at its flagship Las Calandrias project in the Santa Cruz Province of Argentina.

This campaign will test new targets identified adjacent to, below and outside the limits of the current Calandria Sur initial resource estimate as reported on 11 July 2011. The programme will serve to validate the geological model which has been revised through the compilation of detailed surface mapping, trench and outcrop channel sampling, re-sampling of previous drill core and detailed ground magnetics. This work highlights potential for both high-grade and bulk tonnage gold mineralisation hosted by the volcaniclastic rocks surrounding the extensive NW-SE trending Calandria Sur rhyolite dome.

Two outlier targets will also be drill tested. At the Nido Este prospect, 750m NW of Calandria Sur, a single hole will test a prominent NE structural corridor adjacent to a strong chargeability anomaly. At Pichones, 2,500m NW of Calandria Sur, a small erosion window in the volcanic suite has exposed a brecciated chalcedony horizon which may be related to steam heated alteration above mineralisation at depth. Two holes are planned to test the target which has highly anomalous gold pathfinder geochemistry and a coincident high resistivity response from the geophysical survey.

Information derived from this relatively short drill programme will be fundamental in the design of a more extensive drill campaign to be executed in the latter half of 2012.

Commenting today, Chairman John Horsburgh said, "This next campaign follows very encouraging target definition work over the last four months which has defined a mix of both high grade and bulk tonnage style targets."

For further information please visit website at www.marianaresources.com.

About Mariana Resources

Mariana Resources Ltd is an AIM and TSX quoted exploration and development company with an extensive portfolio of gold and silver projects in Argentina and Chile. In southern Argentina, the Company's core gold-silver projects are Las Calandrias (100%), Sierra Blanca (100%), Los Amigos JV (49%) and Aguila-Picadero (100%). These projects are part of a 200,000+ Ha land package in the Deseado Massif epithermal gold-silver district in mining-friendly Santa Cruz Province. In Chile, Mariana has a joint venture with US based international mining and natural resources company Cliffs Natural Resources Inc., to explore for iron oxide-copper-gold deposits in a 92,000 km2 area in north-central Chile along the highly prospective Atacama Fault Zone. Mariana is also evaluating a number of gold-silver and copper-gold opportunities away from the Cliffs JV area.

Safe Harbour

This press release contains "forward-looking information" within the meaning of Canadian securities legislation ("forward-looking statements"). These forward-looking statements are made as at the date of this press release and include, without limitation, statements regarding discussions of future plans, the realization, cost, timing and extent of mineral resource estimates, estimated future exploration expenditures, costs and timing of the development of new deposits, success of exploration activities, permitting time lines, and requirements for additional capital. The words "plans", "expects", "budget", "scheduled", "estimate", "forecasts", "intend", "anticipate", "believe", "may", "will", or similar expressions or variations of such words are intended to identify forward-looking statements. Forward-looking statements are subject to known and unknown risks, uncertainties, assumptions and other factors that may cause actual results to vary materially from those expressed or implied by such forward-looking statements, including, but not limited to: the effects of general economic conditions; the price of gold and silver; misjudgments in the course of preparing forward-looking statements; risks associated with international operations; the need for additional financing; risks inherent in exploration results; conclusions of economic evaluations; changes in project parameters; currency and commodity price fluctuations; title matters; environmental liability claims; unanticipated operational risks; accidents, labour disputes and other risks of the mining industry; delays in obtaining governmental approvals or in the completion of development or construction activities; political risk; and other risks and uncertainties described in the Company's annual information form and MD&A for the most recently completed financial year available on SEDAR. Although we believe that the expectations reflected in such forward-looking statements are based upon reasonable assumptions and have attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such forward-looking statements. Accordingly, readers are cautioned not to place undue reliance on forward-looking statements. We do not undertake to update any forward-looking statements, except in accordance with applicable securities laws.

Incorporated in Guernsey registered number 44276.

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Contacts:

In Australia:

Mariana Resources Ltd

John Horsburgh

Chairman

+61 2 94374588


Mariana Resources Ltd

Glen Parsons

CFO

+61 2 94374588


RFC Ambrian Limited (Nomad)

Rob Adamson

+61 2 9250 0041


RFC Ambrian Limited (Nomad)

Will Souter

+61 2 9250 0050


In U.K.:

Fox Davies Capital (Co UK Broker)

Jonathan Evans

+44 20 3463 5000


St Brides Media and Finance Ltd (PR)

Felicity Edwards

+44 20 7236 1177


RFC Ambrian Limited (Co UK Broker)

Klara Kaczmarek

+44 20 7634 4725


In Canada:

Mariana Resources Ltd (Vancouver Office)

Kathryn Witter

+1 604 669 9336
www.marianaresources.com