(MARL.L) Mariana Resources Ltd Buy/Sell

g/t Ag

Las Calandrias

Las Calandrias Project (formerly Dos Calandrias) now includes the Calandria Sur and Calandria Norte mineralised rhyolite dome complexes in the southeastern part of the project area and the recently discovered El Nido dome complex located to the west (Figure 1).

(Refer to announcement on website at www.marianaresources.com for diagrams)

The 2009 drilling campaign discovered significant disseminated style gold mineralization around the eastern brecciated margin of the Calandria Sur dome. Intersections included 91.5m @ 1.6 g/t Au (CSD 15) and 102m @ 1.2 g/t Au (CSD 13) - News Releases 19/10/09, 28/10/09. El Nido Additional exploration has resulted in the recent discovery of the El Nido rhyolite dome complex. It consists of several coalescent rhyolite domes along a northeast trending 3.5km x 2.5km belt 2km west and northwest of the Calandria Sur and Calandria Norte domes. Veins and sulphide breccias have been identified at El Nido Sur, El Nido Norte and El Nido Centro, mostly at dome margins, indicating possible similarities with Calandria Sur. Recent reconnaissance rock chip sampling at El Nido Norte is encouraging with five out of 13 samples assaying above 1.4 g/t Au, and up to 2.7 g/t Au and 638g/t Ag. El Nido has the potential to generate new targets for drilling in the next campaign.

IP Survey

A leading geophysical company, Quantec Geoscience Limited (Quantec), carried out a 3D IP and Resistivity survey over mapped rhyolite domes at Las Calandrias (Figure 2). Survey dimensions were approximately 1.4 km x 2.5 km using an Offset Pole-Dipole 3D array. The objective was to detect disseminated sulphide zones at depth and better define rhyolite dome geometry. In addition, a N-S pole-dipole test array and five pole-dipole "scout" sections each of 500m were carried out at El Nido.

Sizeable chargeability anomalies were detected within the IP grid at Calandria Sur, Calandria Norte and El Nido Este which could reflect sulphide mineralisation. At Calandrias Sur, the 8mV/V IP anomaly iso-surface produces an elongated figure with approximate dimensions 220m east-west x 350m north-south x 150 depth extent but the largest anomaly is at El Nido Este, measuring approximately 470m N-S x 300m E-W x 150m depth extent.

In a preliminary report and 3D images received from Quantec, Senior Geophysicist, Miles Rideout comments as follows:

"Sizeable IP anomalies were detected both at Calandrias South and Calandrias North demonstrating moderately elevated chargeabilities, peaking at approximately 18 mV/V and 16 mV/V respectively. These two IP anomalies demonstrate the probable distribution of sulphides, which accompany mineralization, and provide new information to extend drill targeting. Several drill holes have shown that mineralization can continue outwards to the 8mV/V chargeability level. The dimensions of the 8 mV/V IP iso-surface anomalies plotted in Figure 4 are reported below. Due to the complex forms of these anomalous features, these dimensions do not represent block volumes.

On the west side of the 3D survey block, a large new chargeable target zone has been detected at the Nido Este target. This new target demonstrates geophysical values similar to the two mineralized zones previously tested (peaking above 18 mV/V), but represents a larger target volume.

The approximate dimensions of this western elongated anomaly (8mV/V cut-off) are 300m east-west x 470m north-south x 150m depth extent. A narrow structural zone extending 200 m further south is also anomalously chargeable and may have mineral potential. Since the Nido Este target is also hosted within rhyolite dome units and shows some evidence of veining at surface. It represents a large probable target of new mineral potential".

Drilling Programme

A minimum of 3,000m of diamond drilling is to commence shortly and is designed primarily to follow up the Calandria Sur discovery. It will target down dip extensions below holes CSD13, 15 and 16, strike extensions, the northern dome margin and the IP anomaly over the centre of the dome (see Figures 2, 3). In addition, IP anomalies at Calandria Norte and El Nido Este will be tested. First assay results are expected from mid-April.

Commenting today, Managing Director of Mariana Resources Ltd, John Sutcliffe said

"The recently discovered 10sq km Las Calandrias - El Nido dome complex greatly increases the exploration potential of the Las Calandrias project for both high-grade vein and bulk tonnage mineralization. The recent IP survey has highlighted some priority concealed targets. An exciting drill campaign is about to start and will follow up the Calandria Sur gold-silver discovery and scout drill selected IP targets elsewhere on the property."

John Sutcliffe

Managing Director

See website at www.marianaresources.com for diagrams or contact the following for additional information.
John Horsburgh (Chairman) Mariana Resources Ltd +61 2 94374588
John Sutcliffe (MD) Mariana Resources Ltd +593 99 808080
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

ADDITIONAL INFORMATION

The exploration programme is being directed by the Argentina Exploration Manager, Dr Gustavo A. Rodriguez under supervision of Managing Director Mr John Sutcliffe. Exploration information in this announcement has been compiled by John Sutcliffe who is a Fellow of the Geological Society of London, a Chartered Engineer and a Member of the Institute of Mining and Metallurgy. Mr Sutcliffe 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 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 ALS Chemex laboratories in Mendoza, Argentina, and assayed in Santiago de 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.

HUG¿1390784 Figure 1 Figure 2 Figure3 Figure 4

For a map showing project area and hole locations go to Mariana's website www.marianaresources.com

Mariana Managing Director John Sutcliffe said, "The Los Amigos Joint Venture offers partners access to a consolidated target area prospective for gold-silver mineralisation. The recent geochemical sampling returned encouraging results with values ranging from 0.1 g/t to 5g/t Au and 5g/t to 100 g/t Ag relating to zones of silicification, quartz veins and sulphide vein breccias. Coupled with new unexplored trends emerging from the airborne magnetic survey, additional exploration is warranted. To date we have drill tested one section along a structure five kilometres long. Although no significant gold-silver mineralisation was encountered, exploration planned for 2010 is designed to define additional drill targets."

Background to Los Amigos JV

Mariana signed a joint venture agreement with Hochschild in November 2009 to explore and develop three adjoining prospective gold-silver tenements totalling 13,455 hectares, located in the Santa Cruz area in the western sector of the Deseado Massif in southern Argentina. These tenements consist of the Company's Amigos I and Amigos II licence areas and Hochschild's San Augustin property which are located approximately 110km south of Hochschild's producing gold-silver San Jose Mine.

The partners agreed to spend US$2 million on exploration within a three year period on a 40% Mariana, 60% Hochschild basis, to confirm participating interests of 49% and 51% respectively. A budget of US$500,000 is committed in the first year.

Under the terms, Hochschild may earn a further 9% by funding 60% of the next US$3 million in the subsequent two years and a further 10% by either completing a Pre-Feasibility Study or, if requested by Mariana, providing project financing, repaid out of 80% of Mariana's share of cash flow. This would see Hochschild's interest increase to 70%.

Hochschild previously held the San Augustin property in a joint venture with IAMGOLD Corporation ('IAMGOLD'). Under the terms of the Hochschild-Mariana joint venture agreement, IAMGOLD will retain a 1.5% of net smelter returns royalty on any future production from the joint venture area.

Previous exploration at Los Amigos is limited. Five holes were drilled in the area in 2005 by Minera Andes Inc. for a total of 1,440 m which followed surface sampling and IP geophysics. The drilling did not intersect economic gold-silver mineralisation, but abundant hydrothermal breccias with a banded chalcedonic quartz-pyrite matrix were reported.

Exploration information in this announcement has been compiled by John Sutcliffe who is a Fellow of the Geological Society of London, a Chartered Engineer and a Member of the Institute of Mining and Metallurgy. Mr Sutcliffe 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.

<<ENDS>>

For further information please see www.marianaresources.com
John Horsburgh (Chairman) Mariana Resources Ltd +61 2 94374588
John Sutcliffe (MD) Mariana Resources Ltd +593 99 808080
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

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. The Company has two gold-silver discoveries and a joint venture with

Hochschild Mining in the highly prospective Deseado Massif region: the Dos Calandrias project indicating a major mineralised system with gold bulk tonnage potential; the Sierra Blanca project, a high grade silver-gold prospect; and
advanced exploration at the Los Amigos JV. In Chile, Mariana has two Iron

Oxide Copper Gold ('IOCG') exploration projects in the highly prospectiveAtacama Fault Zone, approximately 100 km from Freeport's Candelaria Copper Mine: the Buenaventura and Perro Chico projects which comprise 12,000 hectares. In addition, it has a generative pipeline of early stage projects including a major land package totalling approximately 160,000 hectares in southern Argentina.

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