Mira IV Acquisition Corp. V.MRY.P

Intersects 30.1 Metres at 3.9 g/t AuEq (2.2 g/t Au

[yvrean]

Company News Alert

Mariana Drilling Intersects 30.1 Metres at 3.9 g/t AuEq (2.2 g/t Au and 101 g/t Ag) at Sierra Blanca Gold-Silver Project, Southern Argentina (ccnm)

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Aug. 3, 2011) - Mariana Resources Ltd (TSX:MRY)(AIM:MARL)(PLUS:MARL) ('Mariana' or 'the Company') the AIM and TSX quoted exploration and development company focused in Argentina and Chile, announces further positive results from the latest 25 holes of the 31-hole 5,181m 2011 drilling programme at the Chala-Achen zone at its 70% owned Sierra Blanca silver-gold project ('Sierra Blanca') located in the Deseado Massif of the Santa Cruz Province, southern Argentina (Figure 1).

Overview

• Drilling along the 1.1km Chala-Achen vein system has discovered wide intervals of gold-silver mineralisation with high grade zones at Chala Central and Achen.
• Multiple vein breccias up to 40m true width drilled at Achen over 450m strike.
• Best Achen intersection of 20.3m @ 1.5 g/t gold ('Au') and 34 g/t silver ('Ag') (2.0 g/t AuEq**) from 121.7m including 2.65m @ 6.8 g/t Au and 23 g/t Ag from 135.6m in Hole CHD71
• Best Chala Central intersection of 30.1m @ 2.2 g/t Au and 101 g/t Ag (3.9 g/t AuEq) from 23.0m, including 2.1m @ 15.9 g/t Au and 38 g/t Ag(16.5 g/t Au Eq) from 41m in CHD84.
• Chala Splay was tested along 440m strike to 100m depth, with high-grades over 190m strike and best intersection 3.2m @ 406 g/t Ag and 0.7 g/t Au (7.5 g/t AuEq) from 67.0m in CHD79
• Induced Polarisation ('IP') geophysics, detailed mapping and sampling underway at Chala-Achen and other key targets with follow up drilling (6,000m minimum) September 2011
• Mariana has the option to acquire IAMGOLD's 30% interest in Sierra Blanca
• Sierra Blanca is adjacent to TSX quoted Argentex Mining's Pinguino discovery

John Horsburgh, Chairman of Mariana commented, "These drill results are highly encouraging with robust multiple veins, classic epithermal textures and a three kilometres aggregate of veins, all pointing to an impressive target area at Chala-Achen. Additionally, there is the untested two kilometres strike extension under cover to the west of Chala-Achen and other key prospects such as Lucila and Vetarron for drill testing in the next campaign, scheduled to begin in September this year."

Achen Vein System

The Achen vein system (Figure 2) consists of multiple banded quartz-sulphide-manganese carbonate vein breccias with classic intermediate sulphidation epithermal textures and a true width up to 40m. Hole CHD71 intersected 20.3m @ 1.5 g/t gold ('Au') and 34 g/t silver ('Ag') (2.0 g/t AuEq) from 121.7m including 2.65m @ 6.8 g/t Au and 23 g/t Ag from 135.6m. Also Hole CHD61 (announced previously) intersected 28.7m @ 1.4 g/t Au and 11 g/t Ag from 85m and including 3m @ 9.5 g/t Au and 28 g/t Ag (10.0 g/t AuEq) (Figure 3). The vein system has NW-SE and E-W components, a 450m strike and a steep northerly dip. It has been drilled only to 130m depth, is mostly concealed under extensive gravel cover and is open to the west. A possible link with the Lucila vein two kilometres away is indicated by a prominent linear magnetic low (Figure 2).

Best 2011 intersections:

-- CHD61*- 28.7m @ 1.4 g/t Au, 11.5 g/t Ag (1.6 g/t AuEq) from 85.0m
	including 3.0m @ 9.5 g/t Au, 28 g/t Ag (9.9 g/t AuEq) from 87.0m
-- CHD62- 0.6m @ 6.0 g/t Au, 776 g/t Ag (19.0 g/t AuEq) from 111.6m
-- CHD71- 20.3m @ 1.5 g/t Au, 34 g/t Ag (2.1 g/t AuEq) from 121.7m
	including 2.65m @ 6.8 g/t Au, 23 g/t Ag (7.2 g/t AuEq) from 135.6m
-- CHD72- 14.5m @ 1.2 g/t Au, 17.2 g/t Ag (1.5 g/t AuEq) from 126.5m
	including 6.0m @ 2.5 g/t Au, 18 g/t Ag (2.8 g/t AuEq) from 135.0m
-- CHD75- 1.0m @ 0.1 g/t Au, 401 g/t Ag (6.8 g/t AuEq) from 128.5m
-- CHD87- 10.3m @ 0.5 g/t Au, 71 g/t Ag (1.7 g/t AuEq) from 67. m

* Announced 19/04/2011

Two 2008 drill holes also intersected promising mineralisation at shallow depths:

-- 38- 3.0m @ 4.3 g/t Au, 236 g/t Ag (8.3 g/t AuEq) from 30m

-- 40- 4.0m @ 2.3 g/t Au, 120 g/t Ag (4.3 g/t AEq) from 33m

See Figure 4 for longitudinal projection.

Chala Central and Chala Splay

Best Chala Central (Figure 2) intersection from results received was 30.1m @ 2.2 g/t Au and 101 g/t Ag (3.9 g/t AuEq) from 23.0m, including 2.1m @ 15.9 g/t Au and 38 g/t Ag (16.5 g/t Au Eq) from 41m in CHD84. High grade silver mineralisation was intersected in CHD59 (announced previously) with 4.2m @ 1.2 g/t Au and 420 g/t Ag (8.2 g/t AuEq) from 74.6m (Figure 3).

Chala Splay was tested along 440m strike to 100m depth, with high-grades over 190m strike and best intersection 3.2m @ 406 g/t Ag and 0.7 g/t Au (7.5 g/t AuEq) from 67.0m in CHD79 (Figure 3).

Best 2011 intersections:

-- CHD57*- 19.9m @ 0.5 g/t Au and 11 g/t Ag (0.7 g/t AuEq) from 64.8m (Chala Central)
-- CHD59*- 4.2m @ 1.2 g/t Au and 420 g/t Ag (8.2 g/t AuEq) from 74.6m
	including 0.5m @ 3.2 g/t Au & 813 g/t Ag (16.8 g/t AuEq) from 77m (Chala Splay)
-- CHD79- 3.2m @ 0.7 g/t Au and 405 g/t Ag (7.4 g/t AuEq) from 67m
	including 0.9m @ 0.1 g/t Au & 982 g/t Ag (16.5 g/t AuEq) from 68m (Chala Splay)
-- CHD84- 30.1m @ 2.2 g/t Au and 101 g/t Ag (3.9 g/t AuEq) from 23.0m
	including 2.9m @ 1.8 g/t Au & 666 g/t Ag (12.9 g/t AuEq) from 27.4m and 2.1m @ 15.9g/t Au & 38.5 g/t Ag (16.5 g/t AuEq) from 41m (Chala Central)
-- CHD56*- 0.6m @ 4.5 g/t Au and 17 g/t Ag (4.8 g/t AuEq) from 14 m (Chala Central)

* Announced 19/04/11

2008 drill highlights:

-- SBR27- 21.0m @ 0.7 g/t Au and 189 g/t Ag (3.7 g/t AuEq) from 33m
	including 2.0m @ 2.7 g/t Au & 1,435 g/t Ag (26.6 g/t AuEq) from 46m (Chala Central)
-- SBD50- 0.8m @ 3.7 g/t Au and 727 g/t Ag (15.8 g/t Au Eq) from 73.5m (Chala Central)
-- SBD51- 11.0m @ 3.4 g/t Au and 385 g/t Ag (9.8 g/t AuEq) from 46m
	including 2.8m @ 12.7 g/t Au & 1,172 g/t Ag (32.3 g/t AuEq) from 50.2m (Chala Splay)
-- SBD55- 14.3m @ 2.8 g/t Au and 242 g/t Ag (6.8 g/t Au Eq) from 31.7m
	including 1.5m @ 15.2 g/t Au & 775 g/t Ag (28.1 g/t AuEq) from 40.7m (Chala Splay)

See Figure 4 for longitudinal projection.

Other Chala-Achen Targets

In the Chala East target area, hole CHD66, collared 425m east of hole CHD84, intersected two zones of manganese carbonate-quartz sulphide veinlets with anomalous silver and gold extending the Chala-Achen System further east. Hole CHD85 testing the prominent NE- trending low magnetic zone 200m north of Chala-Achen intersected a wide zone of chalcedonic quartz veinlets hosted by a diorite porphyry assaying 6m @ 0.1 g/t Au and 7 g/t Ag from 34m. This prominent structural feature is untested over two kilometres between Chala-Achen and Lucila (Figure 1).

Sierra Blanca Background

The 7,000 Ha Sierra Blanca project is located 70km NW of Cerro Vanguardia along the Tranquilo regional fault system and is adjacent to Argentex Mining's Pinguino epithermal gold-silver/polymetallic discovery (Figure 1). Sierra Blanca is part of the Santa Cruz Joint Venture with IAMGOLD. Mariana holds 70% and has an option to acquire IAMGOLD's 30% by paying US$500,000 cash and issuing Mariana shares to the value US$500,000.

Mariana discovered intermediate sulphidation epithermal gold-silver mineralisation at Veta Chala in 2008. Drilling was limited to 17 reverse circulation and 6 diamond holes totalling 1,750m targeting veins and breccias exposed in trenches from which numerous bonanza and high grade assays were obtained in channel sampling (see news release 02/04/08). Several of these holes were rendered ineffective because of poor diamond core recovery or high water flow in RC holes. 3-D IP, LAG sampling and ground magnetic surveys preceded the recent programme. Chala-Achen is one of several epithermal gold-silver prospects and numerous underexplored veins located within the property.

ADDITIONAL INFORMATION

Drilling was undertaken by ECOMINERA. The drill programme was 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 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. 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.

**Gold Equivalent grade is calculated by dividing silver assays by 60 and adding to the gold value and this assumes metallurgical recovery and net smelter returns are 100%. Intervals are weighted averages with 3m maximum <0.2 g/t Au within the intervals.

For further information and to see the figures referred to in this announcement please visit the website at www.marianaresources.com.

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 km² area ('SCM Mariana Area') in north-central Chile along the highly prospective Atacama Fault Zone. The SCM Mariana Area includes the 44km² Buenaventura and 46km² 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.

Safe Harbour

This press release presents "forward-looking statements" within the meaning of Canadian securities legislation that involve inherent risks and uncertainties. Forward-looking statements include, but are not limited to, statements with respect to the future price of gold and other minerals and metals, the estimation of mineral resources, the capital expenditures, costs and timing of the resources, the realization of mineral reserve estimates, the capital expenditures, costs and timing of the development of new deposits, success of exploration activities, permitting time lines, currency exchange rate fluctuations, requirements for additional capital, government regulation of mining operations, environmental risks, unanticipated reclamation expenses, title disputes or claims and limitations on insurance coverage. Generally, these forward-looking statements can be identified by the use of forward looking terminology such as "plans", "expects" or "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or variations of such words and phrases or state that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved". Forward-looking statements are subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of Mariana to be materially different from those expressed or implied by such forward looking statements, including but not limited to: risks related to international operations, actual results of current exploration activities; actual results of current or future reclamation activities; conclusions of economic evaluations; changes in project parameters as plans continue to be refined; future prices of gold and other minerals and metals; possible variations in ore reserves, grade or recovery rates; failure of equipment or processes to operate as anticipated; accidents, labour disputes and other risks of the mining industry; and delays in obtaining governmental approvals or financing or in the completion of development or construction activities. Although the management of Mariana believes 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 statements. Accordingly, readers should not place undue reliance on forward-looking statements. Mariana Resources does not undertake to update any forward-looking statements that are incorporated by reference herein, except in accordance with applicable securities laws.

FOR FURTHER INFORMATION PLEASE CONTACT:

  John Horsburgh (Chairman) Mariana Resources Ltd [phone] 

  OR

  Glen Parsons (CFO) Mariana Resources Ltd [phone] 

  OR

  Kathryn Witter Mariana Resources Ltd (Vancouver Office) [phone] www.marianaresources.com

  OR

  Rob Adamson RFC Corporate Finance Limited (Nomad) [phone] 

  OR

  Will Souter RFC Corporate Finance Limited (Nomad) [phone] 

  OR

  Matthew Robinson FinnCap (Co UK Broker) [phone] 

  OR

  Jonathan Evans Fox Davies Capital (Co UK Broker) [phone] 

  OR

  Felicity Edwards St Brides Media and Finance Ltd (PR) [phone] 

  OR

  Hugo de Salis St Brides Media and Finance Ltd (PR) [phone] 

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