Tweet

 

Email

Email to a friend:

To:

Separate multiple addresses with commas.

From:

Name: Please send me a copy Message:

Verification code

Enter the code from aboveRequired

Send

RNS Release - News

MARIANA RESOURCES LIMITED
AIM and PLUS code: MARL
TSX: MRY
13 January 2012

Further Phase IV Drilling Results and Project Review Indicate New Targets, Las Calandrias Project, Southern Argentina.

Mariana Resources Ltd ('Mariana' or 'the Company'), the AIM and TSX quoted exploration and development company focused in Argentina and Chile, announces results from 21 of the final 28 holes from a 47 hole - 6,181m Phase IV drill programme at its flagship Las Calandrias gold-silver project ('Las Calandrias') in Santa Cruz province, southern Argentina (see Figure 1).   Results are mostly from the El Clavo, Nido Este, Nido Norte and La Morena targets and follow the initial holes released on 2 November 2011 from La Picasa, Lomo Verde, La Vieja Herradura and El Clavo (see Figure 2).

Overview

• Phase IV drilling indicates potential to expand maiden resource of 519,000 ounces ('oz') gold equivalent ('AuEq') released after Phase II and III drilling 

• Latest results confirm El Clavo (immediately NW of Calandria Sur) as a prime target for bulk-tonnage and deeper high grade gold mineralisation - hosted by phreatomagmatic breccias with substantial intersections of strongly anomalous to low grade gold 

• Best El Clavo intersections include: 83m @ 0.20 g/t Au from 12m, 20m @ 0.40 g/t Au from 40m, 42m @ 0.20 g/t Au from 87m and 40m @ 0.23 g/t Au from 29m  

• Scout drilling at La Morena Vein at Calandria Norte target returned a high grade vein-breccia intersection of 0.5m @ 9 g/t Au and 55 g/t Ag from 34.5m 

• New target zone 500m NW of Calandria Norte opening up - two scout holes at Nido Este intersected anomalous gold with 12m @ 0.2 g/t Au from 3m 

• Other new targets identified at Las Calandrias include SW Calandria Sur dome margins (possible feeder zone), Pichones and Cerro Mojon alteration zones and the Nido Norte - Nido Sur structural corridor 

• Target definition underway with mapping, rock chip/lag sampling, trenching and ground magnetics leading to Phase V drilling in Q2/Q3 2012 

Commenting today, Chairman John Horsburgh said, "The Phase IV drill program has discovered  a large "blind" phreatomagmatic breccia system at El Clavo with substantial intersections of strongly anomalous to low grade gold, the root zones of which could host high grade mineralisation.  This potentially favourable host for epithermal gold, together with scope to expand the Calandria Sur mineralised system into surrounding volcaniclastics, plus new targets opening up elsewhere in and around the dome field, augur well for an exciting Q1/Q2 exploration programme."

Loma Verde/La Picasa/La Vieja Herradura/El Clavo
As reported in the announcement dated 2 November 2011, encouraging gold intercepts hosted by the volcaniclastics have been made along the eastern and northern flanks of the initial resource area (see Figures 2 and 3).  These initial results indicate potential for mineralisation outside the Calandria Sur dome at La Picasa, Loma Verde and La Vieja Herradura.  Best intersections included 40m @ 1.0 g/t Au from 8m - CSD273 and 22m @ 1.1 AuEq (0.6 g/t Au & 30 g/t Ag) from 26m - CSD286.

The latest assay results confirm El Clavo is a newly discovered EW trending phreatomagmatic* breccia zone which has wide zones of strongly anomalous to low grade gold mineralisation.  The 70m wide breccia zone which has minimal surface expression, extends for 450m along strike and is open to the SW.  It 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.

Wide zones of low grade gold (0.1 to 4 g/t Au) and highly anomalous pathfinder elements (arsenic and antimony) have been intersected in most holes (see Figures 2 and 4).  Mariana considers El Clavo to have potential for dome feeder-related gold-silver mineralisation, including possible high grade mineralisation at depth.  Best El Clavo intersections include:

• 83m @ 0.20 g/t Au from 12m - ECD301 

• 19m @ 0.40 g/t Au from 30m - ECD301 

• 20m @ 0.40 g/t Au from 40m - ECD304 

• 42m @ 0.20 g/t Au from 87m - ECD305 

• 40m @ 0.23 g/t Au from 29m - ECD308 

• 54m @ 0.10 g/t Au from 117m - ECD311 

(* Phreatomagmatic breccias are formed by the direct interaction between a magma body and an external water source.  They can represent favourable hosts for epithermal gold mineralisation.)

Six holes remain to be assayed.  Four holes from La Picasa/Lomo Verde and one each from El Clavo and Vieja Herradura.  However, no major quartz veinlet/suphide mineralisation was logged in these holes.

Including El Clavo, the Calandria Sur mineralised 'footprint' now extends over approximately 850m 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 (see Figure 2).  The SW dome margin is identified as a feeder zone target.

La Morena
Scout drilling at La Morena Vein (Calandria Norte) returned a high grade vein-breccia intersection of 0.5m @ 9 g/t Au and 55 g/t Ag from 34.5 m - CND293.  A second hole CND297 did not intersect vein-breccia.

Nido Este
At Nido Este, some 500m to the NW, two scout holes intersected anomalous gold with 12m @ 0.2 g/t Au from 3m - NED309, opening up a new target zone.  Previous Induced Polarisation indicated a large sulphide system at the Nido Este dome, which was tested by only two scout holes in 2010.

Report by Dr J Hedenquist
Internationally recognised independent geological consultant, Dr. Jeffrey Hedenquist, carried out a field visit last quarter.  Dr Hedenquist has consented to the inclusion of the Executive Summary of his report "Observations on the Calandria Au Prospect, Santa Cruz, Argentina", see below.  

In his report, he describes Las Calandrias as numerous altered rhyolite domes with several centres of mineralisation and shallow erosion levels.  He points out that the depth of drilling has not fully tested potential in several areas including dome margins and root zones.  Specific recommendation are made to target both disseminated and deeper feeder structures with possible high grade at Calandria Sur and El Clavo which is described as a phreatomagmatic breccia and assoociated rhyolite dykes.  The full report can be found at
http://marianaresources.com/pdf/reports/Mariana_Calandria_Hedenquist_120110.pdf

Exploration Q1/Q2 2012
The plan for Q1 2012 is to continue assessing all results to date in order to highlight drill targets which have the potential to expand the resource leading to a Phase V drill programme commencing in Q2 2012.  In summary, the potential for expanding the Las Calandrias resource currently includes the following targets/target areas (see Figures 2 and 5):

• Lateral extensions of Calandria Sur gold-silver mineralsiation into adjacent volcaniclastics 

• "Manto" style mineralisation at Loma Verde/La Picasa 

• Possible "feeders" along the SW margin of Calandria Sur 

• Root zones of gold-bearing phreatomagmatic breccia at El Clavo 

• Calandria Norte vein-breccia extensions 

• New Nido Este target area - potential for disseminated style mineralisation 

• Below steam-heated alteration zone at Pichones and Cerro Mojon (see Figure 5) 

• NE-SW structural corridor from Nido Norte to Nido Sur 

Structural/alteration mapping, rock chip/lag sampling, trenching and ground magnetics is already in progress to better define new targets identified so far (see Exploration Models, Figures 2 and 5).  

Summary Phase IV Drilling Results (This report)

Summary Phase IV Drilling Results (Previous report)

* 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.

"Observations on the Calandria Au Prospect, Santa Cruz, Argentina"
Dr J Hedenquist November 2011

Summary and recommendations
Calandria has evidence for high Au grades in structures; although supergene enrichment has to be a concern with high grades in oxidized outcrop, many of the bonanza-grade samples, particularly those from drill core, are clearly associated with sulfides. At Calandria, there are numerous rhyolite domes that are altered in an area of ~4 x 3 km, with several centers of mineralization. Despite the focused drilling at this prospect, there remains potentially viable targets to test; in particular, the present depth of drilling has not fully assessed the potential in several areas, including the margins and roots of the domes at Calandria, given the evidence and suggestions for shallow levels of erosion. An assessment of the clay mineralogy will help the understanding of erosion, as well as zonation around the multiple centers of mineralization.

Mineralization at Calandria is related to fragmental margins of rhyolite domes (Calandria Sur), where it also extends into adjacent tuffs; in the Clavo area, an elongate ~E-W phreatomagmatic breccia and associated rhyolite dikes, cut by NW-SE andesite dikes, may point to a structural focus of a feeder zone for both the rhyolite flow-dome as well as mineralization. Higher grades are related to structures cutting domes (Calandria Norte). At Pichones, a brecciated horizon of chalcedony defines the steam-heated paleo groundwater table, which is close to the elevation of the tops of the nearby Calandria Sur and Norte, suggesting little erosion of these systems; areas of steam-heated alteration may overlie this and other centers of blind mineralization at depth.

Recommendations
Characterize the clay mineralogy in drill hole sections at both Calandria Sur and Norte,and potentially at the surface, to determine if the zonation indicates open directions (with depth and laterally) of higher paleo temperatures, as well as cooler paleo margins.

Plot element ratios (e.g., Ag/Au, Au/As, etc.), in plan and on section, to determine if there are patterns indicating source direction, both at Calandria Sur and Norte as well as in areas adjacent to domes.

Investigate the Picaza and El Clavo areas on the NE and north margins of Calandria Sur, respectively, as well as other areas marginal to the flow dome, both for disseminated mineralization as well as deeper feeder structures with possible higher grades. Where mineralization is associated with lower sulfide concentrations than at Calandria Sur, determine the metallurgical character of the material.

Define the feeder zones of domes, particularly at Calandria Sur, as well as feeders of mineralization, first by considered interpretation of the geology in drill core, and then by deep drilling of the defined targets. The ~E-W phreatomagmatic breccia at El Clavo, with associated rhyolite dikes, is located at the intersection with NW-SE late andesite dikes; this focus is one likely source area of both dome feeder as well as mineralization feeder, and should be tested thoroughly, including the potential for deep high-grade mineralisation in and adjacent to the roots of the diatreme.

Examine the lag and rock geochemical anomalies in the Pichones area, to determine if there are any pathfinder elements that were overprinted by collapse of steam-heated alteration, in order to help target drill holes in this area.

Given the sharp facies changes in and adjacent to the domes, of auto-brecciated fragmental units as well as tuff and volcaniclastic horizons, the complexity of breccias - primary volcanic, phreatomagmatic and hydrothermal, the cross-cutting structural permeability, and variations in alteration and mineralization styles, methodical assessment during subsequent drilling programs will allow the geology and
mineralization controls to be determined as the drilling progresses. This is the most efficient and effective method to assess the mineral potential here.

The metallurgical characteristics of mineralized material, particularly that of the lower grades at Calandria Sur, should be adequately assessed by testing bulk samples of the sulfide material, including that on the margins of the dome.

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/35 m); 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.

Exploration information
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 and Dr Gustavo Rodriguez who is a Member of the Australian Institute of Geoscientists.  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.  Dr Rodriguez 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 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) programme.  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.
**ENDS**

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

For further information please visit website at www.marianaresources.com or contact the following.

Mariana Office Location

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 (100%); 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.

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.