Bonanza at Mariana's Las Calandrias

South America-focused  explorer Mariana Resources (AIM: MARL) has reported bonanza grade gold intersections from its latest two scout drill holes at the Calandria Norte prospect at its Las Calandrias gold project in Argentina. The exceptional gold intercepts included up to 0.75 metres at 443 grams per tonne (g/t) gold.

"The Calandria Norte intersections are truly astounding and underscore the bonanza grade gold potential at Las Calandrias. These holes targeted the untested core of the Calandria Norte rhyolite dome with coincident anomalous chargeability, at a level below the somewhat disappointing 2009 drill intersections”, Mariana MD John Sutcliffe commented. 

Drill-Holes CND45 and CND46 were drilled in an un-tested area in the core of the Calandria Norte dome, coinciding with the centre of a chargeability anomaly. Both holes intersected wide zones of marcasite-pyrite veining and stockworks up to 125m down-hole.  CND45 encountered 5 metres at 81g/t gold and 76g/t silver, from a depth of 92.5 metres, and it included a higher grading 1 metre section at 348g/t gold and 312g/t silver. CND46 cut 4.5 metres at 98g/t gold and 72g/t silver from 81.5 metres, including 0.75m at 443g/t gold and 307g/t silver from 83.9m.

“The bonanza intersections in both holes greatly enhance the potential of this 450m long target”.

According to Mariana, the results indicate potential for high-grade gold mineralisation, down dip of CDN45 and 46, below 2009 gold intersections and also along the entire 450m strike vein-breccia trend.

Furthermore, the company highlighted the major expansion of Las Calandrias gold potential since its discovery in October 2009. Notably with the discovery of high-grade vein-breccias at Calandria Norte, bulk tonnage mineralisation at Calandria Sur and recently discovered El Nido targets.

Las Calandrias - formerly the Dos Calandrias project - extends to include the Calandria Sur and Calandria Norte mineralised rhyolite dome complexes to south-east and the recently discovered El Nido dome complex located to the west. In total the Las Calandrias project now consists of four key target areas: Calandria Sur, Calandria Norte, El Nido Este and El Nido Norte.

“As work advances, Las Calandrias continues to expand and it is becoming evident that the 10.5km2 area of rhyolite domes contains multiple mineralised zones which include both bonanza and bulk mining gold targets. An aggressive follow-up drill programme is being planned which we believe will further define the economic potential of Las Calandrias”, Sutcliffe added.

The company said that the two bonanza intersections are interpreted to be the down dip extension of the Calandria Norte vein-breccia zone, which at surface strikes for at least 450 metres and dips moderately to the north. Subsequently, Mariana said that the entire 450 metre long vein-breccia trend is now a priority target for high-grade mineralisation, and follow-up drilling is being planned.

Additionally, Mariana noted that it is still awaiting further drill results, with 19 holes at Calandria Sur and 7 holes at El Nido due.

Earlier this month, on 5 May, Mariana reported the results from the first seven holes of the 2010 drilling campaign at its Los Calandrias project. The positive results continued to demonstrate wide intersections of gold and silver mineralisation, and indicated bulk tonnage potential.

Intersections from the Calandria Sur target included 64.5 metres at 1.1g/t gold and 20g/t silver including 23.6 metres at 2 g/t gold and 40 g/t silver, 63.5 metres at 1.2 g/t gold and 20 g/t silver including 27.5 metres at 2.2 g/t gold and 34 g/t silver, 63 metres at 0.6 g/t gold and 12 g/t silver including 11 metres at 1 g/t gold and 6 g/t silver, 38.5 metres at 1.7 g/t gold and 13 g/t silver including 5 metres at 7.2 g/t gold and 14 g/t silver, 64 metres at 1.2 g/t gold and 29 g/t silver including 19 metres at 2.2 g/t gold and 43 g/t silver and 7 metres at 2.1 g/t gold and 75 g/t silver, 34.5 metres at 1.3 g/t gold and 20 g/t silver including 10.5 metres at 2.3 g/d gold and 12 g/t silver and 69.5 metres at 2.1 g/t gold and 39 g/t silver including 22 metres at 4.4 g/t gold and 79 g/t silver.

Mariana said that the mineralised zone was open to the southwest and will require further drill testing over an area of approximately 450 m x100 m up to the dome margins.

In its other operation, Mariana recently signed a letter of intent with the US-based miner Cliffs Natural Resources Inc (NYSE:  CLF) to explore for iron-oxide-copper-gold (IOCG) deposits in a 92,000 sq km (square kilometre) area in north-central Chile.

Under the terms of the agreement, Cliffs can acquire a 51% interest in Mariana’s subsidiary Sociedad Contractual Minera Mariana (SCM Mariana), which will be formed for the JV (joint venture), by funding a US$2 million exploration programme and another 19% to take its interest to 70% by spending a further US$1 million. Cliff’s minimum expenditure commitment is US$0.5 million.

The initial exploration focus will be on Mariana’s Buenaventura and Perro Chico projects, where further drilling is planned. Additionally, SCM Mariana will explore for IOCG targets in a 900 km (kilometre)-long zone which extends from Tocopilla to La Serena.

On the 30th April, Mariana reported that a Reverse Circulation (RC) drilling had begun at Perro Chico. The five-hole, 2,000 metre, RC programme is testing a number of IOCG targets generated from a recently completed ground magnetic survey, the 2009 gravity survey, and results from Mariana's previous drilling.  

Additionally, Mariana said that the programme will include the testing of a target to the north of the Belleza prospect, within the property, where it previously intersected 40m at 0.6% copper from 6m and identified a prominent magnetic anomaly to the west-southwest.  

The drilling results are expected by June 2010.