Mariana Resources (LON:MARL, TSE:MRY) said today the results of the Phase IV drilling programme at the Las Calandrias project in Argentina indicated potential for resource expansion and new targets.

Today’s report, which included the results from 21 of the final 28 holes drilled as part of the Phase IV programme at Las Calandrias, follows a set of drilling results in November, which showed potential for mineralisation outside the Calandria Sur deposit.

These results reported today were mostly from the El Clavo, Nido Este, Nido Norte and La Morena targets.

El Clavo was confirmed as a prime target for bulk-tonnage and deeper high grade mineralisation, returning intersections of anomalous low grade gold including grades of up to 0.4 grammes per tonne (g/t) gold across 20 metres.

At the La Morena target, Mariana intersected a high grade interval of 0.5 metres at 9 g/t gold and 55 g/t silver, while two scout holes at Nido Este holes intersected anomalous gold including 0.2 g/t gold across 12 metres, opening up a new target zone.

A previous induced polarisation (IP) survey indicated a large sulphide system at Nido Este, which was tested by only two scout holes in 2010. 

Investors cheered the report, sending shares in Mariana up by 7 percent to trade at 11.5 pence in early deals, valuing the company at £26.3 million.

In addition to the drilling results, Mariana also released a report prepared by independent consultant Jeffrey Hedenquist, who pointed out that the depth of drilling has not fully tested potential in several areas.

He recommended targeting both disseminated and deeper feeder structures with possible high grade at Calandria Sur and El Clavo.

“This potentially favourable host for epithermal gold, together with scope to expand the Calandria Sur mineralised systeminto surrounding volcaniclastics, plus new targets opening up elsewhere in and around the dome field, augur well for an exciting Q1/Q2 exploration programme,” said chairman of Mariana Resources John Horsburgh.

Mariana plans to continue analyzing all results it has received to date during the current quarter to define drill targets for the Phase V drilling programme.

Mapping and sampling to better define new targets that have already been identified is currently in progress.

Six holes remain to be assayed including four holes from La Picasa/Lomo Verde and one each from El Clavo and Vieja Herradura. However, Mariana said these holes did not appear to host major mineralisation.

Broker Fox-Davies said that the results for the El Clavo target, although displaying anomalous grades which indicate the top of a deeper seated epithermal system, look unlikely to be good enough for the target to form a deposit in its own right at open pittable depths. 

“The good news is that Mariana still have a handful of quality targets to follow up including the lateral extension to Calandria Sur and La Picassa which has previously showed very good results (40 m at 1.0 g/t Au and 15 m at 0.9 g/t Au) and is open along strike,” it added.

Oriel Securities added that including El Clavo, the Calandria Sur mineralised 'footprint' now extends over around 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.

Mariana seems to be being overlooked as an exploration company and with AngloGold as a 19.9% shareholder it is one to watch says the broker.

In a private placement, Mariana will receive gross proceeds of £5.4 million from AngloGold in return for 45 million shares at 12 pence per share – a 41-per cent premium to Mariana’s closing price of 8.5 pence per share last night. This means that AngloGold will gain a 19.9 per cent stake in the business.

The terms of the deal state that Mariana will commit to use at least 75 per cent of the new funds to develop its various low-sulphidation epithermal gold-silver deposits located in the Deseado Massif, Santa Cruz Province in Patagonia, Argentina.

Mariana’s Las Calandrias project in the province is estimated to have a preliminary resource of 519,000 ounces of gold equivalent 

“We view the transaction with AngloGold, one of the world’s leading gold producers, as a major endorsement of Las Calandrias Project and its potential to develop into a top tier project with a significant mineral endowment,” said Mariana’s executive chairman, John Horsburgh.

“This alliance further serves to support our belief in the prospectivity of Mariana’s extensive 160,000-hectare land position in Santa Cruz, which includes our second gold-silver discovery at the Sierra Blanca Project. The region contains a number of significant gold-silver mines and projects including AngloGold's Cerro Vanguardia operation."

The firm, reporting results for the nine months to September 30, said that it has continued to advance these two key projects “despite the volatility in equity markets”.

In the summer Mariana announced, following the completion of the third drilling campaign at Las Calandrias, an initial resource estimate of 519,000 ounces of gold equivalent. The resource comprises 11.8 million tonnes indicated at one gram per tonne of gold and 17.4 grams per tonne of silver, as well as 870,000 tonnes inferred at 0.93 grams per tonne of gold and 5.2 grams per tonne of silver.

Since then, drilling results have highlighted that the prospectivity of Las Calandrias has increased significantly.

Meanwhile, drilling results at Sierra Blanca during the period have confirmed wide intervals of gold-silver mineralisation along the 1.1-kilometre Chala-Achen vein system. Following the completion of the first phase of drilling at Las Calandrias, the drill rig was moved in October to Sierra Blanca, where it continues to drill.

During the nine-month period Mariana generated revenue of £38.8 million (first nine months of 2010: £45.9 million). The firm’s loss before tax was £2.8 million (2010: £2 million).

At June 30 it had cash of £5.46 million compared with £8.4 million at the end of March.

It has been a busy period for Mariana as it published a maiden resource estimate for its flagship Las Calandrias project in Argentina of 500,000 ounces of gold equivalent.

The company also listed on the Toronto Stock Exchange. "This platform allows Mariana access to the North American investor market, which is particularly familiar with gold exploration and development companies active in Santa Cruz province in Argentina,” the company said.  

“We look forward to accessing this market and building up liquidity in Mariana’s shares.”

Las Calandrias is divided into two distinct areas: the low grade disseminated gold-silver discovery called Calandria Sur and the nearby high-grade La Calandria vein system.   

Both discoveries are open and possible extensions will be targets in the next campaign.  Then there are other vein systems, that have been only partly tested.

Interestingly, Calandria Sur butts up against the Escondido project owned by Mineral IRL (LON:MIRL), which is also quoted across here on AIM.  

The company’s quarterly and half-year updates revealed Mariana has been incredibly busy, not just at Las Calandrias, but also at its Sierra Blanca project in Argentina, and Jiguata in northern Chile.

The second-quarter loss was £2.07 million, compared with £1.05 million previously.

South America-focused gold miner Mariana Resources (LON:MARL, TSX:MRY) has found further high-grade gold intersects at its Las Calandrias gold-silver project in southern Argentina.

The firm said that results from the final 17 holes from the H1 2011 drilling programme at the Calandria Norte target area found high-grade gold at La Morena and Tongoril vein-breccias that are outside of the La Calandria initial resource at Calandria Norte.

Hole CND250 at La Morena intersected 0.6 metres at 68.1 grams per tonne gold and 107 grams per tonne silver in a vein-braccia from 59 metres depth. This was within a broad ‘stockwork’ intercept of 19.5 metres at 3.3 grams per tonne gold and eight grams per tonne gold from 45 metres depth.

The Tongoril vein-breccia scouth hole CND241 intersected six metres at 1.6 grams per tonne gold and 0.6 grams per tonne gold in a 200 metre north-east/south-west untested vein breccias trend.

Mariana added that the deepest mineralisation to date intersected at the La Calandria vein-breccia 200 metres below surface in CND247. This was 0.53 metres at 23.7 grams per tonne gold and 21 grams per tonne gold from 221.9 metres.

The La Calandria resource estimate is now 886,000 tonnes indicated at 2.26 grams of gold equivalent per ton (contained gold: 61,000 ounces, contained silver: 159,000 ounces) and 366,000 tonnes inferred at 1.17 grams of gold equivalent per tonne (gold: 13,100 ounces, silver: 39,000 ounces). Resource estimates for Calandria Sur and La Calandria are approximately 11.8 million tonnes at  one gram per tonne gold and 17.4 grams per tonne silver indicated, as well as 870,000 tonnes at 0.93 grams per tonne gold and 5.17 grams per tonne silver inferred.

"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," said Mariana's chairman, John Horsburgh. "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  550-metre La Calandria strike extension are compelling targets for the next drill campaign, due to commence in August 2011."

South America-focused gold miner Mariana Resources (LON:MARL, TSX:MRY) has appointed J. Christopher Mitchell as a new non-executive director to its board.

The move is designed to complement the company’s strategy of bolstering its exposure in Canada after the firm’s recent listing on the Toronto Stock Exchange.

Mitchell is a Vancouver-based financial adviser to listed companies active in the mineral exploration and production arena. During his 40-year career, he has served in senior executive positions with several listed mining companies and he currently serves as chief financial officer of several TSX Venture Exchange-listed companies and as a non-executive director of three junior mineral exploration companies.

These companies include Endurance Gold Corporation, First Point Minerals Corporation and Skyline Gold Corporation.

"His specific industry and Canadian experience will be invaluable to Mariana following our listing on TSX and as we look towards expansion of our Las Calandrias  gold-silver resources  in Argentina,” said Mariana’s chairman, John Horsburgh.

Mariana’s shares began trading on the TSX in mid-June. The decision to list there was taken in order to “give the company wider access to the increased institutional and retail shareholder following in the North American markets”, said Horsburgh at the time.

Mariana is focused on gold and copper-gold prospects in Chile, Argentina and elsewhere in South America. The firm’s strategy is to seek underexplored areas with potential for high-grade polymetallic gold mineralisation.

It will take ownership of the 5,600 hectare Jiguata property by acquiring privately held Catalina Resources PLC, with a series of staged payments that puts the value of the assets between US$1.22 million and 1.5 million.

Mariana said the deal is in-line with its project generation initiative to acquire prospective gold, silver and copper properties.  

"We are pleased with the option to earn 100 percent of Jiguata as part of the new project generation initiative announced last year,” said chairman John Horsburgh.

"Early work indicates potential for a concealed high sulphidation gold-silver epithermal system with mapping and IP to define drill targets." 

Mariana is paying US$20,000 now, which will then be followed by a further US$40,000 payment in December this year. A year after that there will be another US$40,000 payment. Then in 2013 US$50,000 will be due on 1 June, follows by a US$150,000 payment on 1 December.

A final US$1.2 million payment is due on the 1 December 2014, but this can be paid before then, and this would also extinguish any outstanding scheduled payments. Catalina will also retain a 2 percent royalty on net smelter returns.

Mariana's Santiago-based exploration team will now put together a work programme to assess the project area.

"This property will be one of the key focus areas of our Chilean exploration team whilst  our Argentinean team remains committed  to progressing and expanding our flagship Las Calandrias gold-silver discovery in Argentina for which Mariana has just released a maiden resource statement," Horsburgh added.

The Santiago team plans to carry out geological mapping and geochemical sampling, which will be followed by Induced Polarisation (IP) geophysics, to identify potential ‘resistive horizons’ at depth. 

These targets would then be following up with either diamond or reverse circulation drilling.

Jiguata comprises 19 exploration concessions, over a total area of 5,600 hectares.  

Describing the area’s geology, Mariana said: "The area largely consists of andesites and volcanic breccias of probable Miocene-Pliocene age showing alteration characteristics of high- sulphidation epithermal gold deposits.  Potential host rocks are mostly covered by younger volcanics.  

"The older, altered rocks are exposed in erosional windows in the younger volcanic cover in the base of valleys."

"It is becoming clear that with only 260 drill holes within a 12 square kilometre rhyolite domefield, and most of those targeting this resource, there is considerable potential to find both extensions to the resource and new zones of mineralisation," said chairman John Horsburgh today.

Calandrias is 5,600 hectares and lies in eastern Santa Cruz and is serviced by the port of Caleta Olivia, 150 km to the north east. It is divided into two distinct areas: the low grade disseminated gold-silver discovery called Calandria Sur and the nearby high-grade La Calandria vein system.

The initial indicated resource estimate for the combined Calandria Sur and La Calandria is 11,840,000 tonnes at 1.10 g/t gold (Au) and 17.4 g/t silver (Ag), Mariana told investors today.

Meanwhile, the initial inferred resource estimate for the combined Calandria Sur and La Calandria is 870,000 tonnes with 0.93 g/t gold and 5.17 g/t silver.

The contained ounces of gold are 381,000 ounces for the indicated resource and 25,900 ounces of inferred resource, said the company.

In terms of silver, contained ounces were 6,624,000 ounces for the indicated resource and 144,000 ounces for the inferred resource.

Of the total contained gold and silver, 29 percent of the gold and and 30 percent of the silver are from oxide/transition material and the remainder from primary sulphide material, said Mariana.

Around 82 percent of the total contained gold and 97 percent of the contained silver are from Calandria Sur, it added.

The company said that 93 percent of the resource tonnage has been assigned to the indicated category.

The reporting cut-off grades were 0.3 g/t AuEq for oxide and transition and 0.7 g/t AuEq for the primary sulphide zone. Gold equivalent (AuEq) was calculated using the long-term silver to gold ratio of 60:1 and was used for reporting cut-off only, said Mariana.

Meanwhile, preliminary testwork has outlined a number of potentially economic processing options, for both the Calandria Sur and La Calandria gold-silver deposits.

Last week, the firm said that it had separated the Calandria Sur deposit into oxide, transition and primary zones for testing.

Oxide ore from the Calandria Sur prospect was tested using two processing options.

A heap leach test produced recoveries of 79.5 percent and 54.5 percent for gold and silver respectively.

Testing using carbon in leach (CIL), a more expensive method than heap leaching, gave recoveries of 94.6 percent for gold and 89.6 percent for silver.

The selective flotation method tested on samples from the primary zone produced a high value concentrate assaying 40.7 grammes per tonne (g/t) gold and 884 g/t silver. Gold and silver recoveries reached 82.1 percent and 82.9 percent respectively.

An alternative processing method, bulk sulphide flotation, was tested on primary zone samples, showing recoveries of 83.3 percent for gold and 75.2 percent for silver.

Mariana favours processing by heap leaching and selective flotation due to their lower capital and operating costs.

At the La Calandria deposit, assays of intercepts using LeachWell technology indicated recoveries of 89.5 percent for the oxide zone, 94.5 percent for the transition zone and 86 percent for the primary zone.

These results mean that economic treatment of all types of mineralisation at La Calandria using the heap leaching and CIL methods may be feasible.

“The excellent recoveries from the oxide, transition and primary mineralization at La Calandria vein indicated by LeachWell assays will stimulate on-going exploration drilling for high grade vein-breccias at Las Calandrias,” chairman Horsburgh had said.

Mariana Resources (LON:MARL), the South America - focused gold miner, announced that its 2011 drill campaign for the promising Los Amigos joint venture in Argentina is underway.

Previous work at Los Amigos, which is 49 percent owned by Mariana, has been promising, with indications the prospect could hold economic potential at depth.

Follow up work to date has identified 19 new targets for further exploration. The Bajo section of Los Amigos, located in the western part of the joint venture area had already been designated a ‘high priority new target area’.

Today, Mariana revealed a diamond drill programme of 2,000m in 13 holes is underway to provide an initial test of the Bajo vein system.  Assay results are expected midway through the third quarter of 2011.

Los Amigos, a joint venture with 51% owner, Hochschild Mining, is located in the western sector of the highly prospective Deseado Massif gold-silver province of Santa Cruz, southern Argentina.

The company’s other prospects in Deseado Massif gold-silver province include the 100% owned Las Calandrias project and 70% owned Sierra Blanca silver-gold prospect.

In April 2011 the company announced positive high grade silver and gold results from the first six holes of its 4,000m 2011 drilling programme at for the Sierra Blanca project.

Elsewhere in South America, the company is active in Chile where it has a joint venture with US based international mining and natural resources company Cliffs Natural Resources. The two companies are exploring for iron oxide-copper-gold deposits in north-central Chile along the highly prospective Atacama fault zone.

Mariana Resources shares opened this morning on 24.38p.

Mariana Resources (LON:MARL) and Hochschild Mining (LON:HOC) have begun drilling work on the Los Amigos gold-silver project in the highly prospective Deseado Massif area in Santa Cruz, Argentina.

A 2,000 metre drill programme is now testing a new high priority target, known as Bajo, in the western part of the joint venture area. In total 13 holes will be drilled and the results are expected in the third quarter of 2011.

In a note to clients finnCap, Mariana’s broker, highlighted that the drilling programme will focus on testing zones of potential mineralisation that was highlighted by recent geophysical surveys and rock chip sampling. 

"Of particular interest is a new target called Bajo where pathfinder minerals associated with epithermal gold silver mineralisation has a strike length of 5 kilometres,” said finnCap analyst Joe Lunn. 

Previously, in the first quarter, the partners carried out varied exploration work across Los Amigos including inverse polarisation (IP) and magnetic surveys as well as geological mapping and sampling.

They found 19 new targets as a result – twelve of them from IP work and seven from geological work.

Describing Bajo’s geology Mariana said: "It comprises sub-outcrop and float of a NW trending swarm of drusy quartz veins with associated breccias, iron oxides, silicification and sinter bodies characteristic of epithermal vein systems.” Importantly the company highlighted that some of the geology is consistent with known epithermal systems in the Deseado Massif.

Hochschild has a 51 percent stake in Los Amigos and Mariana owns the other 49 percent.

Los Amigos comprises Mariana’s Amigos I and Amigos II and Hochschild’s San Augustin tenements. Between them, the partners have stumped up US$2 million for exploration over the next three years, and depending on the results Hochschild may increase its stake in the venture by contributing more cash.

Ultimately Hochschild could earn as much as 70 percent of the venture.