Mariana Resources Ltd. ('Mariana' or 'the Company') (TSX:MRY)(AIM:MARL), the AIM and TSX quoted exploration and development company focused in southern Argentina, Chile and now Peru (see News Releases 4/10/12 & 19/10/12), is pleased to announce very positive results from regional exploration of its extensive portfolio in the eastern Deseado Massif, Santa Cruz (Figure 1).

Overview

--  Multiple zones of gold and silver mineralisation discovered at surface
    in an extensive 7 x 4.5km rhyolite domefield at Los Cisnes (100% owned) 
    
--  Total of six target areas identified within the Los Cisnes domefield,
    with initial exploration focused on the El Solar and El Brio targets 
    
--  The 2 x 2.5km El Solar target area includes a 300 x 600m altered
    brecciated rhyolite dome with 45 float grab samples with anomalous gold
    and silver (10 assays ranging from 0.5 to 3.4 g/t Au) 
    
--  Nearby vein-breccias at El Brio trend ENE-WSW for over 700m with rock
    chip samples returning up to 0.8m @ 3.0 g/t Au 3,849 g/t Ag 

Commenting today, Chairman John Horsburgh said, "These initial results are impressive and further reflect the greenfields prospectivity of Mariana's eastern Deseado portfolio. The discovery of exciting new gold and silver targets over a large area at the 100% owned Cisnes Project in the eastern portfolio has come from some excellent project generation and perceptive follow-up work by Mariana's Santa Cruz exploration team during the winter months. They have successfully applied geological models derived from in-house knowledge gained through the Las Calandrias discovery."

Santa Cruz Regional Exploration

A campaign of first and second pass exploration was carried out over Mariana's extensive properties in the Eastern Deseado Massif, ranging from Bozalito in the north to Los Cisnes in the south (Figure 1). Approximately 30 target areas were generated by Mariana's Santa Cruz team based on Landsat and ASTER image processing. Areas were investigated using a combination of reconnaissance mapping and geochemical prospecting, focusing on zones of alteration and structures in prospective volcanic settings, particularly rhyolite domefields. Sulphidic vein-breccias and altered brecciated rhyolites were prospected in some detail.

Over 400 rock chip grab samples of float and outcrop were collected in this phase at Bozalito, Tongoril II, Bozal I-IV, Leona Dormida, Tres Leones, Aguila/Magnolia, Canadon Pofiado I and Los Cisnes (Figure 1). These grab samples are selective by nature and are unlikely to represent average grades of the deposits.

Los Cisnes Project (100% Mariana)

At Los Cisnes, a large 4.5 x 7 km rhyolite domefield has been discovered (twice the size of the Las Calandrias domefield), with no signs of previous exploration.

Post-mineralisation cover is widespread (approx. 50%) but prospective mineralised dome breccias and related high grade vein-breccias have been identified in float and limited outcrop. Mineralisation styles, host rocks and possible structural controls all indicate a classic rhyolite domefield epithermal setting, thus offering both bulk tonnage and high grade vein-breccia potential. Six key zones of mineralisation have already been outlined and so far at El Solar, El Brio, Destello, El Valle, Presagio and Muro (Figure 2 & 3).

Los Cisnes covers 9,000 Ha and is located about 75km SW of Yamana's Cerro Moro and 120km SSE of Mariana's Las Calandrias projects. Of the 200 samples collected, 71 were strongly anomalous in gold with 27 samples returning assays over 0.5 g/t Au (maximum 11.0 g/t Au). High silver values were also detected at the El Brio target area with 8 samples ranging from 31 g/t Ag to 716 g/t Ag, and one sample assaying 0.8m @ 3,849 g/t Ag.

El Solar - large brecciated rhyolite dome system

El Solar consists of a 2 x 2.5km target area with Calandrias-style sulphidic hydrothermal breccia and vein-breccias, hosted by a strongly altered 600 x 300m rhyolite dome with superimposed intersecting NNW-SSE and E-W structures. Wide-spaced rock chip float sampling returned 45 anomalous gold and silver values, 10 of which ranged from 0.5 to 3.4 g/t Au. Significantly, mineralisation may well extend under adjacent cover.

El Brio & Destello - vein-breccias

El Brio is located on the eastern border of the property, 1km SE of El Solar, and comprises multiple sulphidic quartz-chalcedony vein-breccias (up to 3m wide) along a 700m ENE-WSW trend, hosted by ignimbrites. High grade rock chips were returned along a 250m strike with best assays of 3.0 g/t Au & 3,849 g/t Ag, 11 g/t Au & 716 g/t Ag, 0.5 g/t Au & 666 g/t Ag and 3.2 g/t Au & 398 g/t Ag. The target area may extend under cover along strike.

The Destello target is a large covered area (1.25 x 0.5km) with scattered outcrop and float of strongly oxidized breccia zones hosted by ignimbrites. The main zone is traced over 500m, is up to 2.5 to 4m wide and is developed along a NW-SE structural trend. A total of 13 samples returned strongly anomalous gold and silver, with a best assay of 1.5 g/t Au.

Work Planned

This field season, target definition has commenced and will include detailed mapping, channel rock chip sampling, LAG geochemical sampling, ground magnetics and pole-dipole IP. Follow-up trenching and drilling will be subject to the necessary permitting and access agreements and are in process. Los Cisnes now ranks as a high priority prospect for Mariana and vindicates the Company's focus in the eastern Deseado Massif.

Links: Figure 1 & 2: http://www.marianaresources.com/pdf/release/Mariana_121121.pdf

Exploration Information

Exploration information in this announcement has been compiled by John Horsburgh who is a Fellow of the Australasian Institute of Mining and Metallurgy. Mr Horsburgh has sufficient experience relevant to the style of mineralisation and types of gold deposit under consideration and to the activity that he is undertaking to qualify as a Competent Person as defined in the JORC Code. Mr Horsburgh is a qualified person within the meaning of National Instrument 43-101, Canada.

Quality Assurance/Quality Control

All technical information for the Company's Argentina projects is obtained and reported under a quality assurance and quality control (QA/QC) program. All samples are collected under the supervision of the Company geologists and dispatched via commercial transport to Alex Stewart ALS Chemex laboratories in Mendoza, Argentina, and assayed in Chile. ALS Chemex's quality system complies with the requirements for the International Standards ISO 9001:2000 and ISO 17025: 1999. Samples returning greater than 10 g/t gold and/or greater than 100 g/t silver are assayed using gravimetric analyses. Systematic assaying of sample duplicates and commercially prepared standards and blanks is performed for analytical reliability.

About Mariana Resources

Mariana Resources Ltd is an AIM and TSX quoted exploration and development company with an extensive portfolio of gold, silver and copper projects in South America. In southern Argentina, the Company's core gold-silver projects are Las Calandrias (100%), Sierra Blanca (100%), Los Amigos JV (30%) 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. In Peru, Mariana has an option to earn a 51% interest in highly prospective copper-gold and copper-silver porphyry targets in the Cordillera del Condor of northern Peru.

On 19 December 2011, Mariana announced that AngloGold had completed a strategic placement whereby AngloGold was issued 45,000,000 shares in Mariana at a price of 12 pence per share. AngloGold has the right to maintain its equity of 19.9% in Mariana in further issues by Mariana.

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.

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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.: 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 Fox Davies Capital (Co UK Broker) Jonathan Evans +44 20 3463 5000 In Canada: Mariana Resources Ltd. (Vancouver Office) Kathryn Witter +1 604 669 9336 www.marianaresources.com