Mariana Resources Ltd.

Mariana Resources Ltd.

July 26, 2011 02:00 ET

Mariana Reports High-Grade Gold Intersected at La Morena Vein-Breccia Zone and Extensions to La Calandria Vein-Breccia, Las Calandrias

VANCOUVER, BRITISH COLUMBIA--(Marketwire - July 26, 2011) - Mariana Resources Ltd. (TSX:MRY)(ASX:MARL)(PLUS:MARL) ('Mariana' or 'the Company'), the AIM and TSX quoted exploration and development company focused in Argentina and Chile, is pleased to report on drilling results from the final 17 holes from the Q1/Q2 2011 drilling programme at the Calandria Norte target area at its 100% owned Las Calandrias Gold-Silver Project ('Las Calandrias'), in southern Argentina.


  • Scout drilling intersects first high-grade gold at La Morena and Tongoril vein-breccias outside the La Calandria initial resource outline at Calandria Norte.
  • Hole CND250 at La Morena intersected 0.6m @ 68.1 g/t gold ("Au") and 107 g/t silver ("Ag") (69.9g gold equivalent ("AuEq")) in a vein-breccia from 59m within a broad stockwork intercept of 19.5m @ 3.3 g/t Au and 8 g/t Ag from 45m.
  • The La Morena vein-breccia mineralisation strikes NNE for 350m, dips steeply SSE and is open all directions.
  • Tongoril vein-breccia scout hole CND241 intersected 6m @ 1.6 g/t Au and 0.6 g/t Ag in a 200m NE-SW untested vein-breccia trend, close to the dome margin about 75m SE of La Calandria vein.
  • Deepest mineralisation to date intersected at La Calandria Vein-breccia 200m below surface in CND 247 - 0.53 m @ 23.7 g/t Au and 21 g/t Ag from 221.9m.
  • Shallow scissor hole CND240 in central zone of La Calandria vein-breccia intersected 21.5m of stockwork/breccia @ 1.0 g/t Au and 6 g/t Ag from 31m in the vein footwall.
  • La Calandria Vein-breccia is open at depth to ENE and SSW.
  • The La Calandria trend has increased to over 1km with the discovery of the untested El Clavo mineralised structure striking 550m SW into surrounding volcaniclastics.
  • The 12 holes at La Calandria were not included in the maiden NI 43-101-compliant resource estimate which includes both high-grade vein-breccia and low-grade stockwork mineralization.
  • La Calandria resource estimate is 886,000t Indicated @ 2.26 gAuEq/t (contained gold 61,000 ozs, silver 159,000 ozs) and 366,000t Inferred @ 1.17 gAuEq/t (contained gold 13,100 oz and 39,000 oz silver).
  • Resource estimates for Calandria Sur and La Calandria are 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.

Commenting today, Chairman John Horsburgh said, "Having announced positive results from Calandria Sur drilling last week, we are very encouraged that the gold intersections along the La Morena and Tongoril trends highlight the potential of the Calandria Norte Dome to host multiple vein-breccias. La Morena vein-breccia, the dome root zone where the high grade vein-breccia systems could converge, lateral extensions to La Calandria vein-breccia mineralisation and the untested 550m La Calandria strike extension are compelling targets for the next drill campaign, due to commence in August 2011."

Drilling Programme

Seventy-three diamond holes have been drilled to date at Calandria Norte for 10,586m. The programme last quarter consisted of 17 holes totaling 2,669m. Of these, 12 were drilled at La Calandria vein-breccia, two at La Morena, two at Tongoril and one at other targets. Refer to drill plan (Figure 1) for hole locations, longitudinal section (Figure 2), cross sections (Figures 3-5) and summary of significant intersections in the table below.

The recent resource study has included La Calandria vein-breccia but these drill results were received too late for inclusion in the resource model. The results will be integrated in a subsequent resource update.

La Morena Vein-breccia

One of two holes drilled at the La Morena target in the northern part of Calandria Norte rhyolite dome, 250m NW of La Calandria vein-breccia, intersected high grade mineralisation - 0.6m @ 68.1 g/t Au and 107g/t Ag (69.9 g/t AuEq) from 59m in CND250. La Morena is a branching NNE striking vein-breccia system, dipping steeply SE with a wide hangingwall stockwork.

Seven previous shallow holes intersected concealed chalcedonic silica and sulphide vein-breccia along a 350m trend with a best intersection of 0.8m @ 12.0 g/t Au and 32 g/t Ag from 90m (in CND146). Narrow high-grade silver mineralisation was intersected in CND152, 180m ENE of CND146, with 1m @ 981 g/t Ag from 140 m. The vein-breccia system has no surface expression and was discovered by drilling the SW end of chargeability Induced Polarisation anomaly.

La Calandria Vein-breccia

Results were received for 12 holes drilled as infill or for possible extensions to the vein-breccia system. CND247 which intersected 0.53m @ 23.7 g/t Au and 21 g/t Ag from 221.9m is one of the deepest intersections along the zone 200m below surface which is open at depth and along strike. Hole CND247 is outside the resource outline. The other holes are mostly within the outline and support the initial resource estimation (see below).

In the central-east sector, shallow scissor hole CND240 intersected a wide zone of stockwork veinlets and quartz breccias assaying 21.5m @ 1.0 g/t Au & 6 g/t Ag from 31m in the footwall of the vein-breccia.

In the western lateral zone, two additional holes (CND226-CND227) west of bonanza intersection CND132 - 0.8m @ 90.2 g/t Au and 198 g/t Ag from 132.1m, 120m below surface, did not intersect the vein structure.

The updated gm-m Au longitudinal section (Figure 2) shows +10gm-m Au mineralisation commencing at 30m below surface at its centre and 100m below surface on the flanks. The vein system (up to 1.5m wide) dips steeply NW strikes for 500m and has a vertical extent of 125m, increasing to 200m or more on the northeastern flank. The zone remains open at depth on the ENE and WSW flanks.

Tongoril Vein-breccia

The Tongoril vein-breccia trends NE-SW for approximately 200m close to the dome margin about 75m SE of La Calandria. An intersection in CND241 of 6m @ 1.6 g/t Au, including 1m @ 5.4 g/t Au) opens up another vein-breccia target.

Calandria Norte Exploration Follow Up

Further drilling at La Morena will target extensions and the possible intersection with the La Calandria Vein-breccia at depth.

Mapping, trenching, rock and LAG sampling underway SW of the Calandria Norte Dome has discovered the El Clavo vein trend interpreted as a SW extension of the La Calandria Vein-breccia into the surrounding volcaniclastics. Zones of intense pervasive and vein-style silicification outcrop irregularly over a 550m strike with rock chips assaying between 0.2 and 1.4 g/t Au from initial sampling.

Drilling will resume in Las Calandrias by Mid-August with a minimum of 5,000m planned in the principal target areas.

La Calandria Initial Resource

The initial resource estimate for La Calandria, which includes both high-grade vein-breccia and low-grade stockwork mineralisation, is 886,000t Indicated @ 2.26 gAuEq/t (2.16 g/t Au, 5.6 g/t Ag) - contained gold 61,000 ozs, silver 159,000 ozs. The Inferred resource is 366,000t @ 1.17 gAuEq/t (1.17 g/t Au 3.3 g/t Ag) with contained 13,100 oz gold and 39,000 oz silver.

LeachWell® tests on intercepts from six drill holes have indicated high average recoveries of 89.5% for the oxide zone, 94.5% for the transition zone and 86.0% for the primary zone. Consequently, economic treatment of all the mineralisation at La Calandria by heap leaching or carbon-in-leach (CIL) may be feasible, subject to further LeachWell® tests on the remaining drill holes and testwork.

Calandria Norte Summary Table:
(m) (m) (m) (g/t) (g/t) (g/t)
CND233 40 59.5 19.5 0.4 1 0.4 La Calandria
And 96 99 3 1.2 3 1.2
And 141 142 2 2.7 5 2.7
CND240 12 19 7 1.5 2 1.5 La Calandria
And 31 52.5 21.5 1.0 6 1.0 La Calandria
Inc 40.5 41.25 0.75 5.3 27 5.8
CND241 29 35 6 1.6 0.6 1.6 Tongoril
CND245 115.35 120.9 5.55 0.8 6 0.6 La Calandria
CND247 221.0 228.2 7.2 2.3 3.2 2.3 La Calandria
Inc 221.9 222.43 0.53 23.7 20.6 24.0 La Calandria
CND249 166.6 167.1 0.5 4.6 65 5.7 La Morena
CND250 28.55 31.95 3.4 1.1 13 1.3 La Morena
And 45.0 64.55 19.55 3.3 8 3.4
Inc 59.0 59.6 0.6 68.1 107 69.9
CND252 51 57 6 0.7 2 0.7 Exploratory - West
* Gold Equivalent grade calculated by dividing silver assays by 60 and adding to the gold value and this assumes 100 metallurgical recovery. Intervals are weighted averages with 3m maximum < 0.2 g/t Au within the intervals.

Las Calandrias Project Background

Las Calandrias comprises multiple zones of gold mineralisation hosted by rhyolite domes over a 10.5 sq km area. In 2009, phase I drilling (September-October) consisted of 16 scout holes (1,566m) testing the Calandria Norte vein-breccia and Calandria Sur dome breccia targets where significant gold mineralisation was discovered. The phase II drilling (March-April 2010) consisted of 4,400m in 37 holes and tested Calandria Sur (28 holes/3,212m); Calandria Norte (2 holes/299m), El Nido Este (2 holes/309m) and El Nido Norte (5 holes/580m). The phase III drilling (September-December 2010) consisted of 14,003m in 110 holes; Calandria Sur (56 holes/6,186m); Calandria Norte (43 holes/6,175m); Nido Norte (7 holes/1,054m); Nido Oeste (2 holes/421m); La Herradura (2 holes/168m). The continuity of phase III (January-April 2011) consisted of 15,736 m in 90 holes; Calandria Sur (6 holes/2,747m); Calandria Norte (21 holes/3,430); Despreciada: Nido Norte and Nido Centro (37 holes/6,414m); Nido Oeste (7 holes/1,130m); Nido Sur (18 holes/1,883 m); Gamekeeper (1 hole/132 m).

The Q1 2011 drilling was undertaken by ECOMINERA. The drill programme was directed by the Argentina Exploration Manager, Dr Gustavo Rodriguez (MAIG) 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. 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.

For further information and to view the drill plan map and other figures associated with this press release please visit the website at

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.

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 news release.

Contact Information

  • Mariana Resources Ltd.
    John Horsburgh
    +61 2 9437 4588

    Mariana Resources Ltd.
    Glen Parsons
    +61 2 9437 4588

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

    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

    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