Mariana Resources Ltd.
TSX : MRY
AIM : MARL
PLUS : MARL

Mariana Resources Ltd.

April 03, 2012 08:00 ET

Mariana Resources Discovers New Zones of Volcaniclastic-Hosted Gold-Silver Mineralisation at Las Calandrias Project, Argentina

VANCOUVER, BRITISH COLUMBIA--(Marketwire - April 3, 2012) - Mariana Resources Ltd (TSX:MRY)(AIM:MARL)(PLUS:MARL) ('Mariana' or 'the Company'), the AIM and TSX quoted exploration and development company focused in southern Argentina and Chile, is pleased to announce a positive update from its Las Calandrias gold-silver project located in the world class Santa Cruz mineral district in southern Argentina.

Overview

  • Re-sampling 15 of 40 holes has discovered new zones of vein/stockwork gold-silver mineralisation in silicified volcaniclastics at Calandria Sur
  • Mineralisation extends laterally and below the NI 43-101 compliant initial resource of 441,000 AuEq oz at the rhyolite-hosted bulk tonnage Calandria Sur prospect (Figure 1)
  • Best gold intersections in volcaniclastics lateral to the resource in re-sampled holes, previously considered low priority, include:
    • 52m @ 0.5 g/t Au from 8m - CSD11
    • 7m @ 0.9 g/t Au from 17m - CSD266
    • 8m @ 1.0 g/t Au from 15m & 26m @ 0.6 g/t Au from 29m - CSD275
  • Re-sampling of volcaniclastics below the dome base has extended original rhyolite-hosted intersections in three holes:
    • 69m @ 0.7 g/t Au & 11 g/t Ag from 40m - CSD19 (previously 63m @ 0.6 g/t Au & 11 g/t Ag)
    • 79.5m @ 1.9 g/t Au & 34 g/t Ag from 47m - CSD23 (previously 69.5m @ 2.1 g/t Au & 39 g/t Ag)
    • 93.5m @ 2.2 g/t Au & 33 g/t Ag from 20m - CSD86 (previously 84.5m @ 2.4 g/t Au & 37 g/t Ag)
  • Initial re-sampling of hole CSD222 returned 3m @ 2.4 g/t Au & 12 g/t Ag from 147m and 6m @ 1.7 g/t Au & 17 g/t Ag from 207m, up to 60m below dome-hosted resource base, with assays pending for another 90m of re-sampled core
  • The Calandria Sur mineralised system now extends over an impressive area of 800m NW-SE by 600m NE-SW and up to 170m below surface
  • Intensive further target definition underway at Las Calandrias with integrated results expected this month and Phase V drilling scheduled end Q2/early Q3 2012

To view the Figures referred to in this report go to the following URL: http://www.marianaresources.com/pdf/2012/120403_Mariana_news.pdf

Commenting today, Chairman John Horsburgh said, "These positive first results of the re-sampling programme indicate further gold and silver below and adjacent to the Calandria Sur rhyolite dome resource, in rock types initially considered to be barren. This, together with numerous volcaniclastic-hosted intersections already reported, greatly enhances the potential to expand the Calandria Sur mineralised system in the next drill programme with a view to increasing the resource."

Re-sampling Programme - Extension Potential

The re-appraisal of volcaniclastic drill core was prompted by positive results from the last campaign with veinlet/stockwork style gold mineralisation hosted by volcaniclastic rocks outside the rhyolite-hosted resource areas. In the earlier drilling, the volcaniclastics were not considered to be as prospective as the rhyolites.

Sampling and logging of 40 drill holes within volcaniclastics surrounding the Calandria Sur resource that were not previously sampled are in progress. Results have been received for 15 holes of the first 22-hole batch with new intersections in nine of them. Assays of the remaining seven holes in batch I and another 25 holes in batch II will be released together with new integrated cross sections when received and compiled.

This re-sampling beyond the resource area has revealed significant gold mineralisation hosted by altered silicified volcaniclastic rocks with disseminated sulphides, stockworks and veinlets. High primary permeability of host rocks is considered to have been a factor in localising gold mineralisation. The Calandria Sur mineralised system now extends over an area of 800m NW-SE by 600m NE-SW and up to 170m below surface (Figure 2).

Significant gold assays in volcaniclastics lateral to the resource east of the dome, in holes previously considered low priority, include 52m @ 0.5 g/t Au from 8m - CSD11, 7m @ 0.9 g/t Au from 17m - CSD266 and 8m @ 1.0 g/t Au from 15m & 26m @ 0.6 g/t Au from 29m - CSD275. Mineralisation in CSD275 correlates well with CSD269 and CSD274 and in all three holes the intersections are in the zone of oxidation (Figure 4). Re-sampling of CSD69 gave an intersection of 3.5m @ 1.8 g/t Au from 64m, the first indication of volaniclastic gold on the western side of the dome.

Re-sampling of volcaniclastics below the dome base has extended original intersections in three holes:

  • 69m @ 0.7 g/t Au & 11 g/t Ag from 40m - CSD19 (previously 63m @ 0.6 g/t Au & 11 g/t Ag)
  • 79.5m @ 1.9 g/t Au & 34 g/t Ag from 47m - CSD23 (previously 69.5m @ 2.1 g/t Au & 39 g/t Ag)
  • 93.5m @ 2.2 g/t Au & 33 g/t Ag from 20m - CSD86 (previously 84.5m @ 2.4 g/t Au & 37 g/t Ag)

A broad zone of volcaniclastic-hosted veinlet/stockwork mineralisation associated with manganese carbonates intersected in CSD222 (Figures 3 and 6), up to 60m below the rhyolite dome base, was re-sampled with initial assays of 3m @ 2.4 g/t Au & 12 g/t Ag from 147m and 6m @ 1.7 g/t Au & 17 g/t Ag from 207m. Assays are pending for another 90m of re-sampled core.

These results, together with previous encouraging gold intercepts hosted by the volcaniclastics (2 Nov. 2011, Figure 5), affirm resource potential along the eastern and western flanks of the initial Calandria Sur resource area.

Mineralisation in CSD222 below the dome base indicates new targets between a deeper rhyodacitic porphyry and the rhyolite dome above. Approximately 175m west is another new target zone, a faulted crystal ignimbrite/volcaniclastic contact (Figure 3).

New Target Definition

Structural/alteration mapping, rock chip/lag sampling, trenching and ground magnetics are underway to better define targets/target areas identified to date across the Las Calandrias dome field:

  • Lateral extensions of Calandria Sur gold-silver mineralisation into adjacent volcaniclastics at Loma Verde/La Picasa
  • Possible "feeders" along the SW and NE margins of Calandria Sur
  • Stockwork/veinlet zones between deeper rhyodacite and rhyolite dome base at Calandria Sur
  • Root zones of gold-bearing phreatomagmatic breccia at El Clavo
  • Calandria Norte vein-breccia extensions
  • Nido Este, Pichones and NE-SW structural corridor from Nido Norte to Nido Sur

Phase V Drilling

Phase V drilling is scheduled to commence end Q2/early Q3 after initial drilling at the Aguila-Picadero Project, 50km to the south. The objective is to expand the resource potential at Calandria Sur and to discover new zones of mineralisation in priority areas outlined above which include a number of high grade targets. If results are positive, a resource upgrade would be anticipated Q1, 2013.

Table : Summary of drill core re-sampling

A Previously released intersections
HOLE FROM
(m)
TO
(m)
CORE
LENGTH (m)
GOLD
(g/t)
SILVER
(g/t)
GOLD
Eq*
CSD11
CSD19 40 103 63 0.6 11 0.8
CSD23 47 116.5 69.5 2.1 39 2.8
CSD69 No significant intercept- hole remains in the volcaniclastic
CSD86 20 104.5 84.5 2.4 37 3.0
CSD222 10.00 12.00 2.00 2.4 23 2.8
And 21.00 31.00 10.00 0.3 4
CSD266 not sampled
CSD275 not sampled
B Re-sampled intersections
HOLE FROM
(m)
TO
(m)
CORE
LENGTH (m)
GOLD
(g/t)
SILVER
(g/t)
GOLD
Eq*
CSD11 8.00 60.00 52.00 0.5 1.2
Inc 34.00 41.00 7.00 1.3 2.6
CSD19 40.00 109.60 69.60 0.70 11 0.9
CSD23 47.00 126.50 79.50 1.90 34.40 2.5
CSD69 33.00 37.60 4.60 0.4 2.38
And 64.00 67.50 3.50 1.80 2.80
CSD86 20.00 113.50 93.50 2.20 33.00 2.8
CSD210 96.00 105.00 9.00 0.90 2.10
CSD222 147.00 150.00 3.00 2.4 12.3 2.6
And 207.00 213.00 6 1.70 16.50 2.0
CSD266 17.00 24.00 7.00 0.90 3.7
Inc 17.00 18.20 1.20 2.20 1.4
CSD275 15.00 23.00 8.00 1.00 7
And 29.00 55.00 26.00 0.60 2.6

Gold equivalent grade is calculated by dividing silver assays by 60 and adding to the gold value and this assumes 100% metallurgical recovery. True widths are estimated to be 85-90% of the stated interval.

Las Calandrias Project Background

Las Calandrias comprises multiple zones of gold and silver mineralisation hosted by rhyolite domes and volcaniclastics over a 12 sq km area. To date, 41,885m of drilling has been completed: Phase I (September-October 2009 - 1,566m), Phase II (March-April 2010 - 4,400m), Phase III (September 2010 - April 2011 - 29,738m) and Phase IV (August-September 2011 - 6,181m). The 47 hole Phase IV drilling comprised Calandria Sur bulk tonnage targets outside of maiden resource area (24 holes/3,003m), Calandria Norte high grade target area (3 holes/35 m), Nido Norte (1 hole/210m), Nido Este (2 holes/272m) and El Clavo (17 holes/ 2,343m).

An initial NI 43-101-compliant resource of 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 g/t silver (Ag) Indicated and 870,000t @ 0.93 g/t Au and 5 g/t Ag Inferred.

Exploration information

Exploration information in this announcement has been compiled by John Horsburgh who is a Fellow of the Australasian Institute of Mining and Metallurgy and Dr Gustavo Rodriguez who is a Member of the Australian Institute of Geoscientists. 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. Mr. Horsburgh is a qualified person within the meaning of national Instrument 43-101. Dr Rodriguez 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 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.

For further information please visit website at www.marianaresources.com.

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, the Company's core gold-silver projects are Las Calandrias (100%), Sierra Blanca (100%), Los Amigos JV (49%) and Aguila-Picadero (100%). These projects are part of a 200,000+ Ha land package in the Deseado Massif epithermal gold-silver district in mining-friendly Santa Cruz Province. 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 in a 92,000 km² area in north-central Chile along the highly prospective Atacama Fault Zone. Mariana is also evaluating a number of gold-silver and copper-gold opportunities away from the Cliffs JV area.

On 19 December 2011, Mariana announced that AngloGold had completed a strategic placement whereby AngloGold was issued 45,000,000 shares in Mariana at a price of 12 pence per share. AngloGold has the right to maintain its equity of 19.9% in Mariana in further issues by Mariana.

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.

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Contact Information

  • In Australia:
    Mariana Resources Ltd
    John Horsburgh
    Chairman
    +61 2 94374588

    Mariana Resources Ltd
    Glen Parsons
    CFO
    +61 2 94374588
    www.marianaresources.com

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

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

    In U.K.:
    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

    Ambrian Partners
    Klara Kaczmarek
    +44 20 7634 4725

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

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