Mariana Resources Ltd.
TSX : MRY
AIM : MARL

Mariana Resources Ltd.

September 05, 2012 08:00 ET

Mariana Resources Ltd: Further Gold-Silver Intersections from Las Calandrias Project, Argentina

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Sept. 5, 2012) - Mariana Resources Ltd ('Mariana' or 'the Company') (AIM:MARL)(TSX:MRY), the AIM and TSX quoted exploration and development company focused in southern Argentina and Chile, is pleased to announce positive results of drill campaign V at its Las Calandrias gold-silver project located in the Santa Cruz Gold Province in southern Argentina (Figure 1).

For Figures referred to in this announcement go to the following web address: http://marianaresources.com/pdf/2012/120905_LC_Sept_Figs.pdf

Overview

  • Twenty-one holes drilled for 2,164m including deepening six previous holes, designed to test new targets adjacent to the current Calandria Sur resource of 519,000 ounces gold equivalent ('AuEq') and to validate geological models derived from detailed exploration.
* 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.
  • Significant intersections made in 13 holes - mostly hosted by volcaniclastic or volcaniclastic/rhyolite rocks (see Tables 2 and 3)
  • Intersections range in style from bulk tonnage, narrow high grade (in one case, andesite dyke-related) to wide zones of strongly anomalous gold
  • Post-resource drilling shows a tabular 'halo' of mineralisation around the Calandria Sur dome, especially along the eastern and northwestern borders where NW and NE trending shears and also andesite dykes and NE fractures coincide
  • Best intersections include:
    • 37.7m @ 1.6 g/t gold ('Au'), 6 g/t silver ('Ag') from surface, incl. 25m @ 2.0 g/t Au, 7 g/t Ag from 7m - CSD313 - La Picaza
    • 23m @ 1.1 g/t Au, 4 g/t Ag from 24m - CSD322 - La Picaza
    • 3m @ 14.0 g/t Au, 15 g/t Ag from 8m and 9m @ 1.3 g/t Au, 1 g/t Ag from 29m - CSD320 - Loma Verde
    • 0.7m @ 7.9 g/t Au, 64 g/t Ag from 88.9m - ECD314 - El Clavo
    • 109m @ 0.4 g/t Au, 17 g/t Ag (0.7 g/t AuEq) from 3m - CSD317 - Isabel
  • Other notable intersections included:
    • 71m @ 0.3 g/t Au, 3 g/t Ag from 23m, incl. 14m @ 0.5 g/t Au, 3 g/t Ag from 65m - CSD318 - Isabel
    • 4m @ 1.0 g/t Au, 2 g/t Ag from 1m - CSD319 - Isabel
    • 26m @ 0.5 g/t Au, 2 g/t Ag from 13m - CSD315 - La Picaza
    • 0.6m @ 32.4 g/t Au, 148 g/t Ag from 112.9m - CSD321 - La Picaza
    • 0.7m @ 7.9 g/t Au, 64 g/t Ag from 88.9m - ECD314 - El Clavo
    • 1.7m @ 5.3 g/t Au, 35 g/t Ag from 199m - CSD37 - Dome Base.

Commenting today, Chairman John Horsburgh said, "This is a good set of results from several new targets, all of which are outside the Calandria Sur resource of 519,000 ounces of gold equivalent ('AuEq'). Post-resource drilling to date has assessed the extent of the Calandria Sur mineralised system. Importantly mineralisation at Loma Verde, La Picaza and El Clavo is still open and adjacent covered areas, possible sub-dome feeders, the 1km dyke trend at Calandria Sur and several advanced targets within a 3km radius also remain as targets. Meanwhile, follow-up exploration is underway in the extensive Bozal/Tongoril areas to the north and northwest with new targets emerging, for which we look forward to updating in due course."

Phase V Drilling

The 2,164m drilling campaign was designed to test new targets adjacent to the current Calandria Sur resource of 519,000 ounces ('oz') gold equivalent ('AuEq') and to validate geological models derived from detailed exploration. It included deepening six previous holes. Some outlying targets were not tested as extreme weather prohibited access. Hole locations are shown in Figure 2 and a summary of drill results is in Tables 2 and 3.

The programme confirmed mineralisation lateral to the Calandria Sur dome-hosted resource at Loma Verde and La Picaza. In each case, mineralisation is open further to the east and north-east. Scout drilling of the lightly explored western border at Isabel intersected broad zones of mineralised rhyolite breccia, extending the Calandria Sur footprint further west (Figure 7).

Loma Verde and La Picaza volcaniclastic-hosted mineralisation is located along a 750m NW-SE trending belt on the eastern and northern borders of the dome. Within this area, only 20 scout holes have been drilled to date. The mineralised zone is open in several directions (Figure 7). Six previous holes were deepened beneath the dome, targeting conceptual higher grade "feeder zones" and sub-dome mineralisation. No definite "feeder zones" were intersected but hole CSD42 intersected 26.7m @ 0.6 g/t Au, 4 g/t Ag from 127.1m at the dome base. See cross sections, Figures 3-6.

The post-resource drilling shows a tabular 'halo' of mineralisation around the Calandria Sur rhyolite dome, especially along the eastern and north-western borders. Favourable sites are the coincidence of NW and NE trending shears and also the intersection of andesitic dykes and NE fractures.

Loma Verde Target

Holes CSD320 and 325 were drilled 175m apart in volcaniclastics to test surface rock chips up to 4 g/t Au. Hole CSD320 intersected two zones of strong silicification and minor quartz-siderite veinlets: 3m @ 14.0 g/t Au, 15 g/t Ag from 8m and 9m @ 1.3 g/t Au, 1 g/t Ag from 29m (Section R, Figure 5).

La Picaza Target

CSD313, 315, 321 and 322 intersected mineralisation in both dome rocks and in volcaniclastics, related to coincident NW and NE structures and permeable rock units. Hole CSD313 intersected 37m of rhyolite hosted sheeted veins, veinlets, stockworks and silicification averaging 1.7 g/t AuEq from surface (Section L, Figure 4). Similarly, Hole CSD315, intersected 32m of strong silicification and sulphidic stockworks averaging 0.5 g/t Au from 13m (see Section U, Figure 4). Narrow high grade hydrothermal breccia was encountered in volcaniclastics at 113m in Hole CSD321 with 0.6m @ 32 g/t Au, 148 g/t Ag (see Section C, Figure 6). Also, CSD322 intersected 45m of strong silicification and sulphidic stockworks from surface with 23.0m @ 1.1 g/t Au.

  • 37.65m @ 1.6 g/t Au, 6 g/t Ag from surface, incl. 25m @ 2.0 g/t Au, 7 g/t Ag from 7m - CSD313
  • 23m @ 1.1 g/t Au, 4 g/t Ag from 24m - CSD322
  • 0.6m @ 32 g/t Au, 148 g/t Ag from 112.9m - CSD321

Isabel Target

Holes CSD316 to 319, drilled along the western dome border, intersected wide zones of mineralisation in down-faulted rhyolite (see Section R, Figure 5). The best intersection was CSD317 with 109m of quartz - sulphide veinlets hosted by rhyolite and volcaniclastics, averaging 0.7 g/t AuEq from 3m (Section Q, Figure 5). In CSD316, a shallow zone of limonite fractures was returned 6m @ 0.4 g/t Au. CSD318 was drilled about 60m from CSD317 and intersected quartz sulphide veinlets and disseminations with strongly anomalous gold (71m @ 0.3 g/t Au). A further 60m south, CSD319 intersected 4m @ 1.0 g/t Au near surface within dome-hosted sulphidic stockwork.

  • 6m @ 0.4 g/t Au, 7 g/t Ag from 10m - CSD316
  • 109m @ 0.4 g/t Au, 17 g/t Ag from 3m, incl. 1m @ 6 g/t Au, 1,400 g/t Ag from 20m - CSD317
  • 71m @ 0.3 g/t Au, 3 g/t Ag from 23m incl. 14m @ 0.5 g/t Au, 3 g/t Ag from 65m - CSD318
  • 4m @ 1.0 g/t Au, 2 g/t Ag from 1m - CSD319

Dome Base / Dacite Porphyry Targets

Previous holes CSD10, 12 and 42 were deepened to target extensions of known mineralisation (see Table 3). Weak to low grade gold and silver were intersected in CSD 12 (rhyolite and volcaniclastics) and 42 (rhyolite). Holes CSD23 and CSD37 were extended to test the dacitic porphyritic body below the Calandria Sur dome, with 1.7m @ 5.3 g/t Au, 35 g/t Ag from 199m intersected in CSD37.

  • 12.2m @ 0.4 g/t Au from 104m - CSD12
  • 26.7m @ 0.6 g/t Au, 4 g/t Ag from 127.1m - CSD42
  • 1.7m @ 5.3 g/t Au, 35 g/t Ag from 199m - CSD 37

Andesite Dykes

At El Clavo, hole ECD314 intersected 0.7m of 7.9 g/t Au, 64 g/t Ag from 88.8m in a sulphidic hydrothermal breccia close to an andesitic dyke (Section V, Figure 6). At least three principal dykes have been identified on the Eastern Border of the Calandria Sur dome extending from La Picaza northwest to El Clavo with a cumulative 1 km strike. Fifteen mineralised intersections have been made at dyke boundaries along this trend, of which 8 are significant (see Table 1 below and Section U, Figure 4). Coincidence of NE fractures with the dyke trend is considered favourable for mineralisation. The dyke-related mineralisation is open to the NW (Figure 7).

Table 1: Summary of andesite dyke-related intersections
CSD255 6.5m @ 2.2 g/t Au, 24 g/t Ag from 66m; incl. 0.5m @ 17.0 g/t Au, 183 g/t Ag from 70.3m.
CSD258 32m @ 0.3 g/t Au, 15 g/t Ag from 42m.
CSD261: 35.5m @ 1.8 g/t Au, 6 g/t Ag from 35m; incl. 1.2m @ 20.4 g/t Au, 81 g/t Ag from 60m.
CSD269 6m @ 1.4 g/t Au, 5 g/t Ag from 51.5m.
CSD273 40m @ 1.0 g/t Au from 8m; incl. 1m @ 10.9 g/t Au, 8 g/t Ag from 39m.
CSD274 18m @ 0.7 g/t Au from surface and 15m @ 0.9 g/t Au from 39m.
CSD275 8m @ 1.0 g/t Au, 7 g/t Ag from 15m and 26m @ 0.6 g/t Au from 29m.
ECD314 0.7m @ 7.9 g/t Au, 64 g/t Ag from 88.9m.

Nido Este Target

Two holes at the southeast margin of the Nido Este dome, 550m northwest of the Calandria Norte dome, tested coincident IP chargeability and a NE-SW structure. NED312 and NED324 intersected up to 73m of intense sulphidic rhyolite breccias but with no significant gold mineralisation.

Q3/Q4 2012 Work Planned

Evaluation of the Q1/Q2 2012 re-sampling and latest drill campaign is continuing. At Las Calandrias, drilling to date has gone a long way to mapping the extent of the Calandria Sur mineralised system (Figure 7). However, adjacent covered areas, possible sub-dome feeders, the 1km dyke trend at Calandria Sur and several advanced targets within a 3km radius remain as targets. Meanwhile, follow up exploration is underway in the extensive Bozal/Tongoril areas to the north and northwest. All Las Calandrias dome field and district targets will be assessed in early Q4 and further drilling (Q4 2012/Q1 2013) will be based on the outcome of the prospect ranking. A resource update is anticipated for late Q1 2013.



HOLE

FROM
(m)

TO
(m)
CORE
LENGTH
(m)

GOLD
(g/t)

SILVER
(g/t)

Au
Eq
*


Host
Rock
Oxidation
End of
Oxidation
Hole
La Picaza Target
CSD313 0.00 37.65 37.65 1.6 6.3 1.7 Rhyolite Oxidation 111m
Inc 7.00 32.00 25.00 2.0 7.2 2.1 Dome Zone
CSD315 13.00 39.00 26.00 0.5 1.7 0.5 Volcanic-
lastic
Primary Zone 105m
CSD321 112.90 113.50 0.60 32.40 148.0 34.9 Volcanic-
lastic
Primary Zone 123m
CSD322 24.00 47.00 23.00 1.08 4.1 1.2 Volcanic-
lastic
Primary Zone 96m
El Clavo Target
ECD314 88.90 89.60 0.70 7.9 63.6 9.0 Volcanic-
lastic
Primary Zone 105m
Loma Verde Target
CSD320 9.50 12.50 3.00 14.0 14.7 14.2 Volcanic-
lastic
Trans-
ition
Zone
105m
Isabel Target
CSD316 10.00 16.00 6.00 0.4 6.7 0.5 Rhyolite Dome Oxidation Zone 102m
CSD317 3.00 112.00 109.00 0.4 16.8 0.7 Rhyolite Dome Primary Zone 129m
Inc. 20.00 21.00 1.00 6.1 1400.0 20.4 Rhyolite Dome Oxidation Zone
CSD318 23.00 94.00 71.00 0.3 2.7 Rhyolite Dome Primary Zone 150m
Inc. 65.00 79.00 14.00 0.5 3.3 0.5 Rhyolite Dome Primary Zone
CSD319 1.00 5.00 4.00 1.0 1.6 1.0 Rhyolite Dome Primary Zone 120m
Nido Este Target
NED312 No significant Results 162m
NED324 No significant Results 141m
Calandria Sur Dome
Target
CSD323 No significant Results 90m
CSD326 No significant Results 119m
Lome Verde
Target
CSD325 No significant Results 86.35m
* 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.
Table 3: Campaign V - Previous holes deepened
HOLE FROM
(m)
TO
(m)
CORE
LEN-
GTH
(m)
GOLD
(g/t)
SILVER
(g/t)
Au
Eq*
Host
Rock
Oxida-
tion
End
of
Hole
CSD12 37.40 88.50 51.10 0.6 5.4 0.6 Rhyolite Primary 141m
Inc. 75.00 85.50 10.50 1.2 10.8 1.4 Dome zone
and 104.00 116.15 12.15 0.4 1.6 0.4 Volcaniclastic and Tectonic fault Primary zone
CSD42 69.00 121.00 52.00 0.3 2.0 0.4 Rhyolite Dome Primary zone 179.6m
and 127.12 155.00 28.68 0.6 4.0 0.7 Volcaniclastic and Rhyolite Dome Primary zone
CSD37 3.50 124.00 120.50 0.9 17 1.2 Rhyolite Dome Primary zone 266.3m
and 199.00 200.70 1.70 5.3 35.0 5.9 Volcaniclastic Primary zone
CSD10 38.90 44.90 6.00 1.10 10.0 1.3 Rhyolite Dome Primary zone 152.2m
CSD23 47.00 120.00 73.00 1.90 3.0 Rhyolite Dome Primary zone 237m
CSD84 26.00 69.00 43.00 0.70 3.0 0.8 Volcaniclastic Primary zone 120m

Note: Data relating to hole extensions is in bold italics.

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, 44,049m of drilling have been completed: Phase I (September-October 2009 - 1,566m), Phase II (March-April 2010 - 4,400m), Phase III (September 2010 - April 2011 - 29,738m), Phase IV (August-September 2011 - 6,181m) and Phase V (2,164m).

Mariana released an initial NI 43-101-compliant resource of the Calandria Sur and La Calandria prospects of 491,000 ounces ('oz') AuEq Indicated and 28,000 oz AuEq Inferred on July 2011. The combined estimate was 11,840,000t @ 1.0 g/t Au and 17 g/t 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. 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, Canada.

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 contains "forward-looking information" within the meaning of Canadian securities legislation ("forward-looking statements"). These forward-looking statements are made as at the date of this press release and include, without limitation, statements regarding discussions of future plans, the realization, cost, timing and extent of mineral resource estimates, estimated future exploration expenditures, costs and timing of the development of new deposits, success of exploration activities, permitting time lines, and requirements for additional capital. The words "plans", "expects", "budget", "scheduled", "estimate", "forecasts", "intend", "anticipate", "believe", "may", "will", or similar expressions or variations of such words are intended to identify forward-looking statements. Forward-looking statements are subject to known and unknown risks, uncertainties, assumptions and other factors that may cause actual results to vary materially from those expressed or implied by such forward-looking statements, including, but not limited to: the effects of general economic conditions; the price of gold and silver; misjudgments in the course of preparing forward-looking statements; risks associated with international operations; the need for additional financing; risks inherent in exploration results; conclusions of economic evaluations; changes in project parameters; currency and commodity price fluctuations; title matters; environmental liability claims; unanticipated operational risks; accidents, labour disputes and other risks of the mining industry; delays in obtaining governmental approvals or in the completion of development or construction activities; political risk; and other risks and uncertainties described in the Company's annual information form and MD&A for the most recently completed financial year available on SEDAR. Although we believe 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 forward-looking statements. Accordingly, readers are cautioned not to place undue reliance on forward-looking statements. We do not undertake to update any forward-looking statements, except in accordance with applicable securities laws.

Incorporated in Guernsey registered number 44276.

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Contact Information

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

    Mariana Resources Ltd
    Glen Parsons (CFO)
    +612 94374588

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

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

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

    RFC Ambrian Limited (Co UK Broker)
    Klara Kaczmarek
    +44 20 7634 4725

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

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