Mariana Resources Ltd.

Mariana Resources Ltd.

November 02, 2011 08:00 ET

Mariana Resources Ltd.: First Phase IV Scout Drilling Results Expand Potential at Las Calandrias Gold-Silver Project, Argentina

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Nov. 2, 2011) - Mariana Resources Ltd. ('Mariana' or 'the Company') (TSX:MRY)(AIM:MARL)(PLUS:MARL), the AIM and TSX quoted exploration and development company focused in Argentina and Chile, announces positive results from the first 28 holes of the recently completed Phase IV 47 hole - 6,181m drill programme at its Las Calandrias gold-silver project ('Las Calandrias') in Santa Cruz province, southern Argentina (Figure 1).


  • Prospectivity of Las Calandrias increased significantly with scout drilling of new target areas mostly in volcaniclastics outside of the Calandria Sur resource area (Figure 2)
  • New targets explored - La Picasa, Loma Verde, Vieja Hearradura and El Clavo
  • Extensive mineralised system controlled by NE and NW structures, favourable host rocks and subsurface rhyolite domes
  • Best intersections from latest drilling include – 40m @ 1.0 g/t Au from 8m, including 1m @ 10.8 g/t Au - CSD273 and 22.8m @ 1.1 AuEq (0.6 g/t Au & 30 g/t Ag) from 26m – CSD286
  • Calandria Sur mineralised 'footprint' now extends over circa 800m by 350m-500m with intersections located up to 300m to the east and 120m to the north of the initial resource area at Calandria Sur (Figure 3)
  • Calandria Sur zone remains open in several directions and further drilling is required to test continuity and resource potential
  • Further drilling programme at Las Calandrias to be planned when all Phase IV results are received and follow up mapping and geophysics completed over key target areas

Commenting today, Chairman John Horsburgh said, "These encouraging results demonstrate the potential of the Calandrias Sur mineral system to be expanded substantially in several directions outside the core area. Results further indicate scope for breccia-hosted gold at the new El Clavo target northwest of Calandria Sur. We anticipate follow up drilling in the next few months once all results are in with detailed mapping and geophysics to further outline the targets. We await the next batch of drill results with great interest."

Scout Drilling Results Highlights:

  • At La Picasa, volcaniclastic-hosted mineralisation discovered north of the initial Calandria Sur resource (Figure 4)
    • 40m @ 1.0 g/t Au from 8 m, including 1m @ 10.8 g/t Au - CSD273
    • 18m @ 0.7 g/t Au from 0m and 15m @ 0.9 g/t Au from 31m including 0.6m @ 8.4 g/t Au from 39m - CSD274
  • At Loma Verde, two scout holes 210m east of the resource intersected wide zones of disseminated 'manto-type' gold mineralisation within volcaniclastics (Figure 5)
    • 10m @ 0.8 g/t Au from 4m - CSD270
    • 22m @ 0.6 g/t Au from 2m - CSD272
  • At Vieja Herradura, dome-hosted mineralisation intersected 60m WNW of the initial resource at Calandria Sur
    • 22.8m @ 1.1 AuEq (0.6 g/t Au & 30 g/t Ag) from 26m - CSD286
  • An extensive 70m wide breccia-hosted gold mineralised target zone discovered at El Clavo along a 450m ENE trend adjacent to Calandria Sur deposit with wide intersections of strongly anomalous to low grade gold mineralisation (Figure 6)
    • 19m @ 0.4 g/t Au from 30m - ECD301
  • Results for the remaining nine holes at El Clavo, five holes at Vieja Herradura/Picasa and Loma Verde, and five holes at high grade Calandria Norte, Nido Norte and Nido Este are expected November-December 2011

Loma Verde/La Picasa/Vieja Herradura

The holes reported in this release encountered encouraging intercepts over significant intervals along the eastern and northern flanks of the initial resource area. Mineralisation in this portion of the deposit is hosted by multiple gently dipping favourable units within the volcaniclastics. Gold mineralisation is associated with minor quartz-pyrite/marcasite veining in the primary zone and fracture controlled and disseminated iron oxides after pyrite at shallow levels (Figures 3 to 5).

El Clavo

El Clavo is a newly discovered ENE trending fault-controlled dyke-breccia zone extending SW from Calandria Norte (Figures 2 and 5). The 70m wide breccia zone has minimal surface expression, extends for 450m and is open to the SW. El Clavo comprises rhyolite dykes and breccias emplaced into a sequence of hydrothermally altered tuffs. Mineralisation is characterised by silica flooding, quartz-marcasite veinlets and sulphide disseminations. Low grade gold mineralisation (0.1 to 0.4 g/t Au) and highly anomalous pathfinder elements (arsenic and antimony) have been intersected in most holes. Mariana considers El Clavo to have potential for structurally controlled vein-breccia quartz-sulphide gold-silver mineralisation related to a dome at depth.

Further Exploration

Follow up drilling will be planned when all results from Phase IV drilling are received. Results to date highlight the potential of coincident NW and NE trending structures, favourable host rocks and subsurface rhyolite domes to host sizeable zones of mineralisation in areas beyond the initial resource outline. In particular, the new intersections at the La Picasa target indicate highly prospective NE trending structural corridors which are open along the strike (Figure 2). Follow up exploration will also continue along the El Clavo dyke-breccia zone. The southwestern margin of the Calandria Sur dome is also emerging as a priority target with mapping, sampling and geophysics planned.

Previous Leach Well Assays of Volcaniclastic-hosted Mineralisation

Consulting metallurgist Peter Lewis reviewed the LeachWell results completed Q3 2011 at the Calandria Sur target area and compared the percentages of cyanide extractable gold in the volcaniclastic-hosted and rhyolite dome-hosted primary sulphide mineralisation. This indicated that the volcaniclastic-hosted mineralisation intersected prior to the current drilling programme should yield a higher overall gold extraction by conventional cyanidation than that in the rhyolite dome. In 19 holes there was a total of 78.7 metres of volcaniclastics with head grades >0.5 g/t Au. The weighted average gold extraction from these was 77.4% from an average head grade of 2.24 g/t Au. Hole CSD261, which was collared 30m from the dome margin, intersected multiple sulfide-rich veinlets hosted entirely in volcaniclastics. Of the 18.2 metres of volcaniclastics between 36.0 and 61.2m with a grade >0.5 g/t Au, the average LeachWell gold extraction was 89% from an average head grade of 3.13 g/t Au. LeachWell analyses will also be carried out on selected phase IV drill intersections.

To see Figures 1 to 5 go to:

Summary Phase IV Drilling Results
(to 31 October 2011)
CSD265 18.35 24.00 5.65 1.0 2.7 1.0 Loma Verde
CSD268 5.00 13.00 8.00 0.4 1.8 0.4 La Picasa
CSD269 3.00 9.00 6.00 0.3 1.0 0.3 La Picasa
And 20.00 28.00 8.00 0.7 2.6 0.8 La Picasa
And 51.50 57.50 6.00 1.4 5.0 1.4 La Picasa
CSD270 4.00 14.00 10.00 0.8 2.4 0.8 Loma Verde
CSD271 12.00 27.00 15.00 0.4 1.5 0.4 Loma Verde
CSD272 2.00 24.00 22.00 0.6 1.5 0.6 Loma Verde
CSD273 8.00 48.00 40.00 1.0 2.3 1.0 La Picasa
Inc 39.00 40.00 1.00 10.85 8.4
CSD274 0.00 18.00 18.00 0.7 2.2 0.7 La Picasa
CSD274 31.00 46.00 15.00 0.9 3.6 1.0 La Picasa
Inc 39.00 39.6 0.60 8.42 35.8 9.0
CSD276 41.00 52.00 11.00 0.6 28.6 1.1 La Vieja Herradura
And 62.00 72.00 10.00 0.5 17.7 0.8 La Vieja Herradura
ECD279 116.20 123.00 6.80 0.2 1.2 0.2 El Clavo
CSD282 63.00 80.50 17.50 0.3 6.2 0.4 Vieja Herradura
CSD283 15.00 30.00 15.00 0.3 0.9 0.4 La Picasa
CSD286 26.20 49.00 22.80 0.6 30.0 1.1 Vieja Herradura
CSD287 30.00 32.70 2.70 0.3 4.1 0.4 Loma Verde
CSD289 105.00 106.30 1.30 0.6 0.7 0.6 Loma Verde
ECD292 27.40 30.00 2.60 0.5 2.3 0.5 El Clavo
ECD292 92 92.5 0.50 4.02 16.4 4.3 El Clavo
ECD298 101.00 103.00 2.00 0.4 1.9 0.4 El Clavo
ECD300 25.00 44.00 19.00 0.2 1.9 0.2 El Clavo
ECD301 30.00 49.00 19.00 0.4 5.5 0.4 El Clavo
*Gold equivalent ('AuEq') grade has been calculated by dividing silver assays by 60 and adding to the gold value and this assumes 100% metallurgical recovery.

Las Calandrias Project Background

Las Calandrias comprises multiple zones of gold mineralisation hosted by rhyolite domes and volcaniclastics over a 12 sq km area. To date, a total of 41,885m of drilling has been completed comprising Phase I drilling (September-October 2009 - 1,566m), Phase II drilling (March-April 2010 - 4,400m), Phase IIIA drilling (September-December 2010 - 14,002m) and Phase IIIB (January-April 2011 - 15,736m) and Phase IV drilling (August-September 2011) which consisted of 6,181m in 47 holes; Calandria Sur bulk tonnage target outside of maiden resource area (24 holes/3,003m); Calandria Norte high grade target area (3 holes/35m); Despreciada: Nido Norte (1 hole/210m); Nido Este (2 holes/272m); and El Clavo (17 holes/ 2,343m).

An initial NI 43-101-compliant resource comprising the Calandria Sur and La Calandria target areas of 491,000 ounces ('oz') AuEq Indicated and 28,000 oz AuEq Inferred was released July 2011. The combined estimate was 11,840,000t @ 1.0 g/t gold (Au) and 17.4 g/t silver (Ag) Indicated and 870,000t @ 0.93 g/t Au and 5.17 g/t Ag Inferred.

To see the resources statement, go to:

The fourth drilling programme was undertaken by ECOMINERA. The Company's Argentina Exploration Manager, Dr. Gustavo Rodriguez (MAIG), directed the drill programme under the 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. Mr. Horsburgh is a qualified person within the meaning of National Instrument 43-101.

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 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 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%) in the country. 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.

Incorporated in Guernsey registered number 44276.

Neither the TSX nor its Regulation Services Provider (as that term is defined in the policies of the TSX Exchange) accepts responsibility for the adequacy or accuracy of this release.

Contact Information

  • Mariana Resources Ltd
    John Horsburgh
    +61 2 94374588

    Mariana Resources Ltd
    Glen Parsons
    +612 94374588

    RFC Corporate Finance Limited (Nomad)
    Rob Adamson
    +61 2 9250 0041

    RFC Corporate Finance Limited (Nomad)
    Will Souter
    +61 2 9250 0050

    FinnCap (Broker)
    Matthew Robinson
    +44 20 7600 1658

    Fox Davies Capital (Co UK Broker)
    Jonathan Evans
    +44 20 3463 5000

    St Brides Media and Finance Ltd (PR)
    Felicity Edwards
    +44 20 7236 1177

    St Brides Media and Finance Ltd (PR)
    Hugo de Salis
    +44 20 7236 1177

    Mariana Resources Ltd (Vancouver Office)
    Kathryn Witter
    +1 604 669 9336

    Renmark Financial Communications (PR)
    Arash Shahi
    +1 514 939 3989

    Renmark Financial Communications (PR)
    Philip Robin
    +1 416 644 2020