Argentina Mining's Blog I Latest news on Mining in Argentina

Este blog fue creado para publicar novedades sobre la mineria en Argentina, complementando así nuestro web y presencia en redes sociales. Como todas nuestras actividades, apunta a conectar a la comunidad minera argentina y establecer un ámbito de promoción de la actividad en el mundo, generando oportunidades de negocios.
---
This blog was created to publish news on argentinean mining, thus complementing our website and presence in social networks. As all of our activities, it intends to connect the mining community in Argentina and provide a place to promote the activity in the world, developing business opportunities.

30 abr. 2011

Soltera Mining Corp.: Explanation of the El Torno Eluvial Gold Sampling Results


JUJUY, ARGENTINA--(Marketwire - April 27, 2011) - Dr. Fabio Montanari, President and CEO of Soltera Mining Corp. (PINK SHEETS:SLTA)(FRANKFURT:SN7) (www.solteramining.com) wishes to offer further details regarding the results of the El Torno eluvial gold sampling program carried out in November 2010.

Given the level of concern expressed by shareholders and apparent misunderstanding resulting from our news release of April 21, Soltera management offers this follow up release which states explicitly the significance of the assay results in the context of the rest of the El Torno prospect.

The sampling program was designed specifically to test eluvial deposits composed of weathered bedrock that have been worked in the recent past by the mineral title owner who processed the material through a gravity processing plant located some 3 km from the sample area. Samples were split into six size fractions in the ALS laboratory and analyzed by a combination of fire assay, cyanide leaching and emission spectroscopy; detailed lab work that took the better part of three months to complete.

Soltera has now received all 392 analyses from the sampling program. The sampling area covered approximately 40 hectares (99 acres), including part of the current Exploitation Licence, which covers 30 hectares (74 acres). The results provide useful information on possible gold targets for further exploration work; however, the easily accessible eluvial (weathered) deposits, which were to be the feed material for immediate small-scale production, do not appear to contain sufficient gold to justify this short-term initiative. Any possible immediate gold exploitation from this specific area will likely require milling the hardrock.

The analytical results do show that traces of gold are widespread through both the surface eluvial material and the underlying bedrock, but values over 1 g/t are scarce and erratic. Specifically, approximately 95% of the 392 analyses showed trace gold, with six containing more than 1 g/t Au (with one sample showing 11 g/t) and the rest containing less than 0.1 g/t Au.

Given the above, the most likely locations for plant feed are within the large and strong geochemical anomalies discovered in 2008 that cover several hundred hectares of the Exploration Licence and which are different from the main gold-quartz vein system. A reconnaissance check on these areas will be part of the first stage of exploration of these major bedrock targets.

Soltera plans to focus ongoing exploration activities on the two major gold targets at El Torno: the large gold-bearing vein systems that cross the licence area; and the potential open-pit areas outlined by the 2008 geochemical surveys. Both have potential for several million ounces of gold and all indications to date are that a considerable proportion of the gold is free and can be recovered by ethical means.

Background of Sampled Area

The El Torno area contains three types of gold deposit; major gold-bearing vein systems, large potential open-pit areas, and relatively small 'eluvial' deposits which consist of surface weathered material derived from gold-bearing bedrock. The sampling aimed to provide information primarily on the eluvial material and, to a lesser extent, on the bedrock that hosts the larger-scale targets.

The eluvial material occurs in broad patches, usually 2 to 3 metres deep, distributed throughout the area. It is easily worked and, in fact, was extracted from one area by the mineral title owner until three years ago when he ceased operations due to ill health. The weathered gold-bearing material was dug by backhoe and transported some 3 kilometres to a simple gravity processing plant located just outside the El Torno title area.

Prior to the sampling there was no firm data on the tonnage or grade potential of the eluvial material, but there certainly appeared to be substantial tonnages suitable for processing. Small gold nuggets were recovered from the gravity plant operation and it seemed highly likely that considerable fine pure gold was lost in the recovery process.

Sampling Program Objectives

The main objectives of the sampling program were to:

* determine in broad terms the tonnage and gold content of eluvial material available for processing,
* determine the amounts of gold in different size fractions of the plant feed in order to find out how much fine gold was being lost and the best methods for its recovery, and
* provide information on the rock types underlying the eluvial material as a guide for the major vein and open-pit target exploration.

Sampling Program Details

Twenty trenches were dug on the exploitation licence area, covering around 40 hectares, and 77 samples sent for preparation and analysis. Of these, 44 were channel samples of eluvial material taken along the sides of the trenches and 33 were chip samples of the underlying bedrock exposed in the trenches.

The majority of the samples were sieved in the laboratory into six size fractions and the coarser fractions were analysed for gold by cyanidation which should extract all the oxidized gold in the sample, and by fire assay which analyses total gold. The coarsest fractions were also analysed for 32 elements by emission spectroscopy. The fine fractions were analysed by cyanidation alone. The main objective was to find out where the gold was concentrated so that the existing gravity processing plant recovery rate could be improved.

Sample Program Results

Although approximately 95% of the 392 analyses showed trace gold, only six contained more than 1 g/t Au (up to 11 g/t) and the rest mainly less than 0.1 g/t Au. The mean of all the samples (excluding the highest value of 11 g/t) is 0.12 g/t Au.

The sampling area covered approximately 40 hectares (98.8 acres), including part of the current Exploitation Licence which covers 30 hectares (74.1 acres). This location contains the thickest development of eluvium in the exploitation area, and a major objective was to establish in broad terms the volume of potential feed for the beneficiation plant. The analytical results show that traces of gold are widespread through both the surface eluvial material and the underlying bedrock, but values over 1 g/t are scarce and erratic. They indicate, in fact, that only very small tonnages of eluvial material in the test area would be suitable feed for the plant, perhaps a few thousand cubic metres.

However, the results provide some guidelines for locating suitable plant feed. We know that previous plant feed was taken from relatively close to the gold mineralised vein system within a strong geochemical gold anomaly and that it yielded visible gold in the plant concentrates. By contrast, the sampled area was outside any main geochemical gold anomaly except in the extreme southwest where Pit 20 showed 4.8 g/t (+180 mesh fraction) in a bedrock sample. In other words, any potential feed for the plant is likely to be from eluvial deposits located within strong geochemical anomalies.

Eluvium over the main mineralised vein system is often thin, but can be thicker over the main open-pit targets. We think that a reconnaissance check on the strong geochemical gold anomalies that cover several hundred hectares within the Exploration Licence's 7,900 hectares (19,513 acres) is warranted. This check can be carried out as part of the first phase of exploration work for the major vein and open-pit bedrock targets.

One unconnected but important point is that there is generally good correlation between the fire assay and cyanidation extraction data. This correlation indicates that the bulk of the gold in the samples analyzed was free gold.

Conclusions

From the above, we conclude that there is an insufficient tonnage of suitable plant feed in the current Exploitation License area, which covers 30 hectares (74.1 acres) out of a total exploration area of 7900 hectares (19,513 acres), to justify a commercial operation. However, there may be gold-bearing eluvial cover within the many strong geochemical gold anomalies and, although the eluvium is likely to be thin in places, these are worth checking out as part of the first stage of exploration for the major deposits.

We plan at this stage to focus our efforts on the main El Torno gold targets: the major gold-bearing vein systems that cross the licence area; and the potential large-scale open-pit areas outlined by the 2008 geochemical surveys. Both have potential for several million ounces of gold. Furthermore, all available evidence indicates that the bulk of the gold is free and can probably be recovered by simple gravitational methods. As part of this approach, we plan to verify and validate the historic drill data from Puma Minerals, Peñoles and CODELCO using a combination of geophysical surveys and drilling, and if verified, start to crush and mill the hardrock before processing it through our existing gravity concentration plant.

Safe Harbor Statement: Certain statements contained herein are "forward-looking" statements (as such term is defined in the Private Securities Reform Act of 1995). Because such statements include risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Information or opinions in this document are presented solely for informative purposes and are not intended nor should be construed as investment advice. We encourage you to carefully review the Company with your investment advisor and verify any information that is important to your investment decision.


No hay comentarios:

Publicar un comentario en la entrada

Thanks for your interest on Argentina Mining's Blog. Please leave your comment on this article in spanish or english. / Gracias por su interés en el Blog de Argentina Mining. Por favor deje su comentario sobre este artículo en español o inglés.