Mariana Resources Ltd, the AIM quoted exploration and development company focused in Argentina and Chile, has commenced drilling at its 70% owned Sierra Blanca Silver-Gold Project, located in the Deseado Massif gold district in southern Argentina.

Overview
• 4,000m drill programme underway primarily targeting the 1.4km Veta Chala silver-gold epithermal vein system to depths of up to 200m below surface

• Impressive intersections from 2008 scout drilling programme to be followed up include: 3.0m @ 4.3 g/t Au & 236 g/t, 11.0m @ 3.4 g/t Au & 386 g/t Ag and 14.3m @ 2.8 g/t Au & 242 g/t Ag

• Recent soil sampling (up to 10.2 g/t Au in lag), ground magnetics and Induced
Polarisation surveys have highlighted new targets at Central and Eastern Chala
Commenting today, Chairman John Horsburgh said, “The previous exploration results
highlight the exploration potential of Sierra Blanca. The 1.4km long trending silver-gold
vein system is a prime target with intersections such as 11.0m @ 3.4 g/t Au & 386 g/t
Ag. The aim is to quantify the economic potential with this 4,000m campaign. Coupled
with our flagship Las Calandrias gold project, this will enhance Mariana’s position as a
leading exploration player in the Santa Cruz region with significant upside.”

Sierra Blanca Silver-Gold Project
Mariana discovered intermediate sulphidation epithermal vein-style silver-goldmineralisation along the Veta Chala target area in 2008. Veta Chala is an east-west striking vein system occurring within a 1,400m x 300m area. Targets along the trend comprise the Chala West, Chala Central and Chala Splay. Cumulative strike length of individual veins at surface is about 2.2km. The 2008 drilling was limited to 17 Reverse Circulation (‘RC’) and six diamond holes totaling 1,750m with less than half of the 1.4km long vein system tested to a depth of 60m. The scout drilling targeted 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 2 April 2008 and results below).

• 4.5m @ 3.6 g/t Au, 694 g/t Ag
• 16.5m @ 0.5 g/t Au, 384 g/t Ag
• 9.4m @ 0.9 g/t Au, 236 g/t Ag
• 8.3m @ 1.7 g/t Au, 507 g/t Ag
• 9.4m @ 1.3 g/t Au, 2,362 g/t Ag
• 3.4m @ 10.1 g/t Au, 1,238 g/t Ag

Best intersections from the 2008 scout drilling campaign included:
• 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 - SBR27
• 3.0m @ 4.3 g/t Au, 236 g/t Ag from 30m - SBR38
• 4.0m @ 2.3 g/t Au, 120 g/t Ag from 33m - SBR40
• 0.75m @ 3.7 g/t Au 727 g/t Ag from 23.5m SBR50
• 11.0m @ 3.4 g/t Au, 386 g/t Ag from 4m incl. 2.8m @ 12.7 g/t Au 1,172 g/t Ag -
SBD51
• 14.3m @ 2.8 g/t Au, 242 g/t Ag from 31m incl. 1.5m @ 15.2 g/t Au and 775 g/t
Ag - SBD55

A review by consultant epithermal specialist Dr. R. H. Sillitoe in Q1 2009 indicated
potential for vein type economic ore shoots along the Veta Chala trend with infill and
deeper drilling recommended (see news release 2 March 2009).

The current drilling programme will both undercut and infill 2008 intersections and test
new targets along the trend.

Mariana owns 70% of Sierra Blanca and has an option to acquire the 30% held by joint
venture partners IAMGOLD by paying US$500,000, issuing Mariana shares to the value
of US$500,000 and awarding a 3% royalty on net smelter returns from any future goldsilver production at Sierra Blanca.

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 area.

The lag sampling outlined other gold anomalies to the north and south of Veta Chala
trend.

Veta Chala Geophysical Surveys
Mariana carried out ground magnetics over a 3.2km x 2.7km area on 50m spaced lines
and Induced Polarisation surveys 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.

Las Calandrias Project – Santa Cruz, southern Argentina
Mariana is currently drill testing for extensions to the Calandria Norte vein system and
Calandria Sur. Assays are pending from 65 holes at El Nido, Nido Norte, Calandria Norte and Calandria Sur.

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 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.

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) programme. 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. ACME 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.