Mariana Resources Ltd ('Mariana' or 'the Company'), the AIM quoted exploration and development company focused in Argentina and Chile, announces further encouraging results from the third drilling campaign at the Calandria Norte prospect ('Calandria Norte'), one of several key target areas at the Company's 100% owned flagship Las Calandrias Gold-Silver Project ('Las Calandrias'), located in the prospective Deseado Massif gold-silver district in Southern Argentina.

Overview:

  • Results from first 16 holes from infill and exploratory drilling campaign at Calandria Norte indicate potential for developing significant high grade gold-silver mineralisation within an extensive rhyolite dome-hosted stockwork zone; 

  • Four additional bonanza grade vein-breccia intersections at La Calandria Vein  

  • Best intersection of 11.5m @ 10.5 g/t Au and 53 g/t Ag from 85m, including 2.40m @ 43.0 g/t Au & 218 g/t Ag from 89.3m (CND125) 

  • Other highlights include 12m @ 8.0 g/t Au and 9 g/t Ag from 101m including 0.6m @ 123.0 g/t Au & 93 g/t Ag (CND122) and 28.6m @ 4.0 g/t Au and 17 g/t Ag from 77.4m including 0.45m @ 140.5 g/t Au & 312 g/t Ag (CND123) 

  • Infill and exploratory drilling planned on La Calandria Vein which extends for 400m strike and is open at depth to the WSW and ENE  

  • Shallow scout drilling of covered target north of La Calandria has discovered La Morena Vein with 0.8m @ 12.0 g/t Au and 32 g/t Ag from 89.7m (CND146) - follow up drilling planned 

  • Assays  pending from 11 other Calandria Norte holes 

  • Two rigs currently testing new Induced Polarisation ('IP') targets in the El Nido Area (6,000m minimum) - first results expected February 2011 

 

Commenting today, Chairman John Horsburgh said, These results indicate resource potential at Calandria Norte with further exploratory and infill drilling planned.  In the meantime, two drill rigs are currently testing multiple targets in the El Nido area with initial results expected next month.
Mariana has drilled 53 diamond drill holes at Calandria Norte to date for a total of 7,706m (see news release dated 15 October 2010).  The last programme in 2010 consisted of 44 holes for a total of 6,175 metres.  Of these, 22 were at La Calandria Vein, seven at La Morena Vein target and four at other targets.  Results have been received for 20 La Calandria Vein holes and two of the seven La Morena holes, with remaining assays pending.  

Hole locations, longitudinal section, cross sections are shown on the drill plans (see figures 1-5) and a summary of intersections is included in the table at the bottom of the release.

La Calandria Vein

 

High grade gold-silver vein-breccia intersections occur within a sulphidic stockwork which extends over a 400m strike and approximately 20-100m in width.  The longitudinal gm-m Au (gm Au x metres) section shows +10gm-m Au mineralisation commencing at 30-90m below surface, open to the WSW and ENE along 400m strike and at depth.  The vein system consists of NE trending vein-breccias (up to 1.5m wide) dipping steeply NW and sulphidic stockwork veinlets striking ENE dipping steeply SE.  Bonanza gold mineralisation occurs at the intersection of the breccias and hanging wall stockwork veinlets along the vein trend.  Apart from two deeper holes (CND 149 and 150 - assays pending), La Calandria Vein trend is untested beyond a depth of 150m.  Further exploratory and infill drilling of the Calandria Norte vein-breccia trends will follow drilling at El Nido (30% complete).  

Subject to follow-up drilling and modelling at Calandria Norte, the scope of the preliminary resource estimation for Calandria Sur could be expanded to include Calandria Norte.  The completion of the Calandria Sur resource study is expected Q2 2011.

 

Central Bonanza Zone

 

Holes CND122 and CND123 indicate reasonable continuity in the Central Bonanza Zone, with intersections of 0.6m @ 123 g/t Au and 93 g/t Ag from 104.6m and 0.45m @ 140.5 g/t Au and 312 g/t Ag from 79.9m, respectively.  A central core of five intersections of +100gm-m Au mineralisation strikes 150m and occurs in a vertical range between 50m to 135m below surface.  The high grade mineralisation appears to terminate about 150m below surface in the central zone, e.g. CND124 intersected a sulfide breccia with no significant gold mineralisation 20m below bonanza hole CND61 (0.95m @ 139.5 g/t Au and 107 g/t Ag from 120.4m).  In this case, the favourable intersection of the vein-breccia with stockwork veinlets is not present.  However, adjacent deeper hole CND127 with 9.9m @ 1.5 g/t Au from 141m indicates mineralisation can persist to 150m below surface in the central zone.

Central Zone intersections of interest include:

  • CND122 - 12m @ 8.0 g/t Au and 9 g/t Ag from 101m including 0.6m @ 123.0 g/t Au & 93 g/t Ag from 104.6 m 

  • CND123 - 28.6m @ 4.0 g/t Au and 17 g/t Ag from 77.4m including 0.45m @ 140.5 g/t Au & 312 g/t Ag from 79.9m 

  • CND125 - 11.5m @ 10.5 g/t Au and 53 g/t Ag from 85m including 2.40m @ 43.0 g/t Au & 218 g/t Ag from 89.3 

  • CND126 - 17m @ 1.0 g/t Au 2.7 g/t Ag from 110m 

  • CND127 - 9.5m @ 1.7 g/t Au from 103m 

  • CND134 - 7.7m @ 4.1 g/t Au from 77.3m 

Previously announced Central Zone bonanza intersections are:

  • CND 45 - 4.0m @ 75.9 g/t Au and 70 g/t Ag from 92.5m 

  • CND 46 - 4.5m @ 101.8 g/t Au and 70 g/t Ag from 81.5m 

  • CND60 - 0.44m @ 30.5 g/t gold & 145 g/t silver from 91.7m 

  • CND61 - 5m @ 34.1 g/t Au and 32 g/t Ag from 119m. 

  • CND64 - 0.75m @ 33.1 g/t Au & 41 g/t Ag from 70.4m 

 

Lateral Zones

 

The drilling indicates that the vein-breccia mineralisation (+25gm-m Au) is open to the WSW (CND131 and 132) and ENE (CND137).  An encouraging intersection was obtained in CND131 - 7.0m @ 5.6 g/t Au and 6 g/t Ag from 120.5m, including 1.0m @ 11.5 g/t Au and 10.3 g/t Ag from 125m.  A bonanza intersection was returned for the westernmost hole, CND132 - 0.8m @ 90.2 g/t Au and 198 g/t Ag from 132.1m, 120m below surface and 50m below low grade mineralisation in CND07 (5.2m @ 0.6 g/t Au, from 87.1m).  The deepest and easternmost intersection was 13.5m @ 3.0 g/t Au and 7 g/t Ag from 159m, (CND137), 150m below surface.

Lateral Zone intersections of interest:

  • CND129 - 8.0m @ 2.2 g/t Au and 2 g/t Ag from 91m including 0.65m @ 21.1 g/t Au & 18 g/t Ag from 92.95m 

  • CND131 - 7.0m @ 5.6 g/t Au and 6 g/t Ag from 120.5m         

  • CND132 - 0.8m @ 90.2 g/t Au and 198 g/t Ag from 132.1m 

  • CND 137 - 13.5m @ 3.0 g/t Au and 7 g/t Ag from 159m including 1m @ 15.5 g/t Au & 20 g/t Ag from 168m. 

La Morena Vein

 

La Morena is a new concealed target located in the northern part of Calandria Norte rhyolite dome.  Seven shallow scout holes tested a NE trending IP anomaly parallel to La Calandria bonanza vein, 270m to the north.  Chalcedonic silica-sulphide vein-breccia was intersected along a 350m strike with the two holes received indicating gold mineralisation:

  • CND144 - 1.7m @ 1.6 g/t Au and 7 g/t Ag from 58.8m 

  • CND146 - 0.8m @ 12.0 g/t Au and 32 g/t Ag from 89.7m 

Las Calandrias Project Background

Las Calandrias comprises multiple zones of gold mineralisation hosted by rhyolite domes over a 10.5 km2 area.  In 2009, 16 scout holes (1,763m) tested the Calandria Norte vein-breccia and Calandria Sur dome breccia targets where significant gold mineralisation was discovered (see news release 28 October 2009).  The Q1/Q2 2010 drill programme 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 Q3 2010 programme consisted of 14,004 m in 109 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).

Table 1: Calandria Norte Drill Intersection Summary

CALANDRIA NORTE 
 HOLE PARAMETERSINTERCEPTTarget
HOLEUTMEUTMNALTAZDIPDEPTHFROMTOCORE LENGTHGOLDSILVER 
(masl)(°)(-°)(m)(m)(m)(m)(g/t)(g/t) 
CND12261399347252881933204512610111312.008.09La Calandria Vein Zone
Inc      104.60105.200.60123.093 
CND12361408347253771943204512577.410628.604.017La Calandria Vein Zone
Inc      79.9080.350.45140.5312 
CND124613923472545518014060174   NSVNSVLa Calandria Vein Zone
CND12561393247254061861406012085.0096.5011.5010.553La Calandria Vein Zone
Inc      89.3091.702.4043.0218 
CND12661391647254251831406014411012717.001.03La Calandria Vein Zone
Inc      117.00117.550.556.2715.5 
CND127613899472544418014060162103112.59.501.75.9La Calandria Vein Zone
Inc      106.00107.001.006.095.2 
And      141150.99.901.58.9 
CND128613884472542418114060183144.3151.156.850.36.0La Calandria Vein Zone
CND12961386047253751851406016368.8574.65.751.43.5La Calandria Vein Zone
Inc      70.3070.700.406.069.1 
CND129      91998.002.22.3 
Inc      92.9593.600.6521.1017.7 
CND129      120.5128.58.002.15.0 
CND130613830472541017914060180No vein breccia intersectedNSVNSVLa Calandria Vein Zone
CND131613812472535218014060162120.5127.57.005.65.7La Calandria Vein Zone
Inc      125126111.5010.3 
CND132613770472532418114060159132.1132.90.890.2198La Calandria Vein Zone
And      138.0141.53.51.51 
CND13361368447253151701406099No vein breccia intersectedNSVNSVExploratory
CND13461403347254781891406014777.385.07.74.16La Calandria Vein Zone
Inc      8082.42.48.913 
CND135614005472551118414060183120.0131.011.00.6 La Calandria Vein Zone
CND13661406947255121901406014757.0058.001.004.33La Calandria Vein Zone
And      77.5106.028.500.56 
CND137614039472554918414060189808661.34La Calandria Vein Zone
CND137      159.0172.513.53.07 
Inc      168169115.519 
CND138614075472558118814060160Assay pending   La Calandria Vein Zone
CND139614004472547818614060153Assay pending   La Calandria Vein Zone
CND140614074472546919314060156Assay pending   La Calandria Vein Zone
CND141613863472541418214060183Assay pending   La Calandria Vein Zone
CND142613682472543617629060105Assay pending   Exploratory-northern part
CND143613688472561018314060111No vein breccia intersected  Exploratory-La Morena
CND1446137144725522180320608558.860.51.71.67La Morena vein
CND14561358147253741722106066No vein breccia intersected  Exploratory-western part
CND14661374547255291803206010589.191.01.95.416La Morena vein
Inc      89.7090.500.8012.032 
CND147613627472539917614050124No vein breccia intersected  Exploratory-western part
CND148613738472548717832060180Assay pending   La Morena vein
CND149613853472547718014050238Assay pending   La Calandria Vein Zone
CND150613875472549018214055261Assay pending   La Calandria Vein Zone
CND151613767472555118132060150Assay pending    La Morena vein
CND152613923472557418832060147Assay pending   La Morena vein
CND153613959472562219032060122Assay pending    La Morena vein

Intervals are weighted averages with 3m maximum < 0.2 g/t Au within the intervals.

ADDITIONAL INFORMATION

Drilling is being undertaken by ECOMINERA. The drill programme is being directed by the Argentina Exploration Manager, Dr Gustavo Rodriguez 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.

 

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 Santiago de 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**

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

John Horsburgh (Chairman)Mariana Resources Ltd+61 2 94374588
Glen Parson (CFO)Mariana Resources Ltd+612 94374588
Rob AdamsonRFC Corporate Finance Limited (Nomad)+61 2 9250 0041
Will SouterRFC Corporate Finance Limited (Nomad)+61 2 9250 0050
Joe Lunn (Analyst)                  FinnCap (Broker)+44 20 7600 1658
Matthew Robinson                  FinnCap (Broker)+44 20 7600 1658
Felicity EdwardsSt Brides Media and Finance Ltd (PR)+44 20 7236 1177
Hugo de SalisSt Brides Media and Finance Ltd (PR)+44 20 7236 1177

About Mariana Resources
Mariana Resources Ltd is an AIM 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%).  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 initiati