[cid:image003.gif@01CBFE6B.F9B42680] Mariana Resources Ltd AIM and PLUS code: MARL 19 April 2011 High Grade Silver and Gold Mineralisation Intersected - Sierra Blanca Project, Southern Argentina Mariana Resources Ltd (Mariana or the Company) the AIM quoted exploration and development company focused in Argentina and Chile, announces positive high grade silver and gold results from the first six holes of its 4,000m 2011 drilling programme at its Sierra Blanca silver-gold project (Sierra Blanca) located in the Deseado Massif of the Santa Cruz Province, southern Argentina. Overview � Completed 2,200m of drilling over 15 drill holes at Sierra Blanca - assays received for six holes totalling 650m � High grade silver mineralisation intersected in twin hole CHD59 at Chala Splay target in the eastern Veta Chala target area - 4.2m @ 420 g/t Ag and 1.2 g/t Au from 74.6m. � Wide zones of manganese-carbonate-quartz-sulphide vein breccias discovered at the Achen vein system (formerly Chala West) in the western sector of 1.4km Veta Chala target area � Best Achen vein system intersection: 3m @ 9.5 g/t gold (Au) and 28 g/t silver (Ag) within a broader zone of 28.7m @ 1.4 g/t Au and 11 g/t Ag from 85m in Hole CHD61 � Multiple zones of vein breccias up to 35m wide intersected in all Achen vein system holes over a strike length of at least 450m and 130m below surface (assays pending). � Drill campaign expanded to 5,000m to test the full extent of silver and gold mineralisation of the Veta Chala target area
John Horsburgh, Chairman of Mariana commented, "These initial results from what is potentially a robust vein system at Achen with both high grade and broader stockwork mineralisation are excellent and substantially upgrade the economic potential of the Veta Chala target area.

Additionally, bonanza grade silver mineralisation of 4.2m @ 420 g/t Ag was intersected at the Chala Splay prospect highlighting it as another prime target for follow up.

Drilling will now focus on depth and strike extensions of an essentially concealed vein system, extending for at least 450m and open to the west under gravel cover plus testing of other targets at our Sierra Blanca silver-gold project." Achen Vein System The Achen vein system (Figure 1) consists of quartz-sulphide-manganese carbonate vein breccias located in the western part of the Veta Chala target area.

The vein system has a north-westerly trend with an east-west component apparent and dips steeply to the north.

True widths will be established with further drilling; however vein breccias plus enveloping stockworks over approximately 40m true width have been identified in holes to date. Hole CHD61 (figure 2) intersected multiple quartz-carbonate-sulphide vein zones over 40% downhole length.

An interval averaging 1.4 g/t Au and 11 g/t Ag over 28.7m from 85m depth, included several high grade gold intervals with best intercept of 3m @ 9.5 g/ Au and 28 g/t Ag. The vein intersection in CHD61 is approximately 25m down dip of the intercepts received in hole SBR39 (10m @ 0.05 g/t Au and 10 g/t Ag) from the Companys 2008 reverse circulation drilling programme and shows a dramatic increase in vein grade with depth.

The shallow hole SBR39 intersected multiple manganese carbonate and quartz vein breccias 40m below surface. The Achen vein system is composed of banded fine to coarse grained quartz, adularia, rhodochrosite, rhodonite and sulphide, all of which display textures typically found in intermediate sulphidation epithermal vein systems.

The vein system is mostly concealed under extensive gravel cover and is open to the west.

Two 2008 drill holes also intersected promising mineralisation at shallow depths: SBR 38 - 3.0m @ 4.3 g/t Au, 236 g/t Ag from 30m SBR 40 - 4.0m @ 2.3 g/t Au, 120 g/t Ag from 33m Results are pending for another 9 holes drilled to date, mostly along the Achen vein system. Chala Central and Chala Splay Bonanza grade silver mineralisation was intersected in 2011 drill hole CHD59 at the Chala Splay target within the main Veta Chala zone with 4.2m @ 420 g/t Ag and 1.2 g/t Au from 74.6m (figure 3).

This was a twin diamond hole of the Companys 2008 reverse circulation (RC) hole SBR28 which assayed 4m @ 0.1 g/t Au 44 g/t Ag.

The RC hole was rendered ineffective because of high water flows below the water table.

Other intersections from initial 2011 drill hole results were: � Hole CHD56 - 6 m @ 4.5 g/t Au and 17 g/t Ag from 146 m (Chala Central) � Hole CHD57 - 19.9 m @ 0.5 g/t Au and 11 g/t Ag from 64.8m (Chala Central) � Hole CHD59 - 4.2 m @ 1.2 g/t Au and 420 g/t Ag from 74.6m (Chala Splay) including 0.5 m @ 3.2 g/t Au & 813 g/t Ag from 77 A complete table of drill results will be provided in the next news release. Sierra Blanca Gold-Silver Project - Additional Background Information The Sierra Blanca project is part of the Santa Cruz Joint Venture with IAMGOLD (which is not contributing to the exploration programme).

Mariana holds 70% and has an option to acquire IAMGOLDs 30% by paying US$500,000 and issuing Mariana shares to the value US$500,000. Mariana discovered intermediate sulphidation epithermal vein-style gold mineralisation along the east-west trending 1,400 x 300m Veta Chala target area in 2008, however lacked the resources to fully test the zone at that time.

Target areas along the trend comprised Chala West (now known as the Achen Vein System), Chala Central and Chala Splay.

The 2008 drilling was limited to 17 RC and 6 diamond holes totalling 1,750m targeting multi-stage epithermal quartz veining and breccias exposed along the trend in backhoe trenches from which numerous bonanza and high grade assays were obtained in channel sampling (see news release 02/04/08).

Mariana completed additional 3-D Induced Polarisation (IP) and ground magnetic surveys in 2010 before designing the current drilling programme which includes drill testing of anomalies outside the Veta Chala vein system.

Recent surface geochemical sampling (up to 10.2 g/t Au in lag soils), ground magnetics and IP surveys at Sierra Blancas Veta Chala target have highlighted new targets at Central and Eastern Chala zones. 2008 Backhoe Channel Sampling The current drilling is testing the vein system at depths well below base of oxidation.

The backhoe sampling in 2008 achieved some outstanding results and indicated the potential for silver-rich mineralisation in the untested oxide zone.

Backhoe sampling results from 2008 are listed below:
* 4.5m @ 694 g/t Ag and 3.6 g/t Au incl.

0.5m @ 5,480 g/t Ag and 25.7 g/t Au * 1.5m @ 384 g/t Ag and 0.5 g/t Au * 9.4m @ 236 g/t Ag and 0.9 g/t Au * 8.3m @ 507 g/t Ag and 1.7 g/t Au incl.

1m @ 3,630 g/t Ag and 6.5 g/t Au * 94m @ 2,362 g/t Ag and 1.3 g/t Au * 3.4m @ 1,238 g/t Ag and 10.1 g/t Au * 3.5m @ 465 g/t Ag and 3.7 g/t Au * 9.4m @ 1,211 g/t Ag and 1 g/t Au 2008 Drill Highlights Several of the 2008 holes intersected significant mineralisation and further highlights the prospectivity of the vein trend:
* SBR27 - 9.0m @ 0.9 g/t Au and 426 g/t Ag from 44m incl.

2.0m @ 2.7 g/t Au, 1,435 g/t Ag) * SBR 38 - 3.0m @ 4.3 g/t Au, 236 g/t Ag from 30m * SBR 40 - 4.0m @ 2.3 g/t Au, 120 g/t Ag from 33m * SBR 48 -13.0m @ 0.5 g/t Au, 49 g/t Ag from 69m * SBD 51 -11.0m @ 3.4 g/t Au, 386 g/t Ag from 4m incl.

2.8 m@ 12.7 g/t Au 1,172 g/t Ag * SBD 55 -14.3m @ 2.8 g/t Au, 242 g/t Ag from 31m incl.

1 .5 m@ 15.2 g/t Au and 775 g/t Ag. A review by epithermal specialist consultant Dr.

R.

H.

Sillitoe in 2009 indicated potential for economic ore shoots along the Veta Chala zone with infill and deeper drilling recommended (see news release 2 March 2009). 2010/2011 Exploration Veta Chala Geochemical Sampling Geochemical sampling of the coarse soil fraction on a 50m x 50m grid at the Veta Chala target revealed a coherent 1,300m x 350m zone of +10ppb Au including a 900m x 200m core of +50ppb Au.

High gold values (>250 ppb to 10,200 ppb Au) over a 500m x 120m area highlight Central and Eastern Chala as key target zones within the Veta Chala target area.

The lag sampling outlined other gold anomalies to the north and south of the Veta Chala target. Geophysical Surveys Mariana has carried out ground magnetics over a 3.2km x 2.7km area on 50m spaced lines and IP comprising gradient array (1.5km x 1.5km area, 25m dipole spacing) and 3D offset pole-dipole (1m x 1.4km area, 25m line spacing, 20m dipoles).

Magnetic lows highlight structures north of the Veta Chala target.

Coincident magnetic, chargeability and resistivity anomalies were located 500m south of Chala West.

A number of chargeability anomalies along the Veta Chala trend indicate possible sulphides at depth.

Anomalous chargeability was also recorded west of Chala Splay where bonanza silver intercepts were returned in the 2008 drilling. ADDITIONAL INFORMATION Drilling is being undertaken by ECOMINERA.

The drill programme is being directed by the Argentina Exploration Manager, Dr Gustavo Rodriguez under supervision of Executive Chairman Mr John Horsburgh.

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 mineralization 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. Quality Assurance/Quality Control All technical information for the Companys 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 ALS laboratories in Mendoza, Argentina, and assayed in Santiago de Chile.

ALS 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. **ENDS** For further information please visit website at www.marianaresources.com or contact the following. John Horsburgh (Chairman) Mariana Resources Ltd +61 2 94374588 Glen Parsons (CFO) Mariana Resources Ltd +612 94374588 Rob Adamson RFC Corporate Finance Limited (Nomad) +61 2 9250 0041 Will Souter RFC Corporate Finance Limited (Nomad) +61 2 9250 0050 Joe Lunn (Analyst) FinnCap (Broker) +44 20 7600 1658 Matthew Robinson FinnCap (Broker) +44 20 7600 1658 Felicity Edwards St Brides Media and Finance Ltd (PR) +44 20 7236 1177 Hugo de Salis St Brides Media and Finance Ltd (PR) +44 20 7236 1177
About Mariana Resources Mariana Resources Ltd is an AIM quoted exploration and development company with an extensive portfolio of gold, silver and copper projects in Argentina and Chile.

In Southern Argentina, in addition to the Las Calandrias gold-silver discovery, the Company has the Sierra Blanca silver-gold prospect (70%); the Los Amigos joint venture (49%) with Hochschild Mining and a 160,000 Ha land package (100%).

All of these projects are located in the Deseado Massif epithermal gold-silver district in mining-friendly Santa Cruz province of southern Argentina, which hosts four mines and several advanced projects. 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 (IOCG) in a 92,000 km� area (SCM Mariana Area) in north-central Chile along the highly prospective Atacama Fault Zone.

The SCM Mariana Area includes the 44km� Buenaventura and 46km� Perro Chico IOCG projects.

Mariana is also evaluating a number of gold-silver and copper-gold opportunities away from the Cliffs JV area, as part of a new initiative.
Felicity Edwards St Brides Media and Finance Ltd Chaucer House 38 Bow Lane London EC4M 9AY Tel: +44 (0) 207 236 1177 Mob: +44 (0) 7748 843871 Fax: +44 (0) 207 236 1188 Email: Web: www.stbridesmedia.co.uk