OTTAWA, ONTARIO--(Marketwire - May 22, 2012) - Aura Silver Resources Inc. (TSX VENTURE:AUU) ("Aura" or the "Company") is pleased to announce that it has refined its gold and silver drill targets at its 100% owned Greyhound property using an Organo-Sulphur Geochemical ("OSG") analysis based on mineral bacterial activity. This analysis was performed by Activation Laboratories ("Actlabs") of Ancaster Ontario for Aura. In a previous press release (see #11-16, dated December 13, 2011), Aura announced robust results from Organic Soil Gas Hydrocarbon ("SGH") analyses which identified one gold zone and two silver zones at Greyhound. Each is a specific drill target located to the east and south east of Aura Lake, the area where spectacular grades in gold and silver boulders have been discovered. This area has not been previously drilled by Aura. The Organic SGH analysis, which identifies hydrocarbons as decomposition products from bacterial activity specific to gold and to silver mineralization, has proven in past studies to identify mineralization directly below where hydrocarbon-enriched soil samples have been collected. This has been the case even if the soil or rock samples had undergone surficial transport from above the mineral source.
Organic SGH - Previous Results
The results of the Organic SGH analysis identified a possible source target for both the high-grade surface samples of gold and the silver. The following map (see Figure 1: https://media3.marketwire.com/docs/Figure1PR.pdf ) of the Aura Lake area of Aura's Greyhound property shows the drill targets for gold and silver as delineated by the oval figures which surround the strongest showings of Organic SGH.
Furthermore, the drill targets identified were rated by Actlabs with their highest priority in confidence in comparison to the response from other known deposits. The gold zone to the north east was given the second highest rating by Actlabs, the north east silver zone the highest rating and the southeast silver zone a similarly high rating. These are highly prospective ratings as supported by the organic SGH results.
The Organic SGH analysis has a history of outstanding performance in the past in terms of locating mineralization in both blind tests and in practice. Organic SGH and its interpretation have been refined for over 15 years. Two recent studies show the effectiveness of the Organic SGH technology:
i. Dr. Richard Dyer (April 2012): McFaulds Lake, Ring of Fire area at McFaulds Lake (https://www.actlabs.com/files/Richard_Dyer-OGS- SGH_delineates_Ring_of_Fire_camp_with_Lake_Sediments.pdf);
and
ii. Dave Heberlein (2010): Mt. Milligan site in B.C. for Geoscience BC (https://www.geosciencebc.com/i/project_data/GBC_Report2010- 8/GBC_Report2010-8_Report.pdf).
In this study, Dr. Heberlein conducted over twenty different geochemical tests on the Mt. Milligan project. Actlabs' organic SGH test was one of two that accurately located the Mt. Milligan deposit directly below the soils tested for organic SGH compounds
Organo-Sulphur Geochemical Update
Organo-Sulphur Geochemical analysis detects specific sulphur based hydrocarbons related to the sulphur component of ore-deposit minerals. This analysis compliments and refines the previous SGH study, by defining these targets to a point where the targets now have the highest priority rating. According to Actlabs, the highest level rating achieved by the three targets indicates that "the SGH classes most important to describing a gold-related (or silver-related) hydrocarbon signature are all present and consistently vector with the same location with well-defined anomalies".
The following maps indicate:
1. The now well-defined gold zone to the north as compared to the originally defined targets (see Figure 2: https://media3.marketwire.com/docs/Figure2PR.pdf);
2. The north east silver zone which may indicate a shallow structure (see Figure 3: https://media3.marketwire.com/docs/Figure3-4PR.pdf); and,
3. The south east silver structure which may indicate a deeper structure (see Figure 4: https://media3.marketwire.com/docs/Figure3-4PR.pdf).
This analysis suggests that the two potentially shallow targets, centered at less than 300 metres below surface, represent both the gold zone and the north east silver zone. The south east silver zone is predicted by the latest 3D-SGH interpretation process to be 500 metres or more below surface. The Company believes the combined results of the Organic SGH and the Organo-Sulphur geochemical analysis of Greyhound explains a number of aspects related to our exploration to date:
This recent high-tech analytical approach to exploration results defines:
1. The sources of the high-grade surface samples to the east and southeast of Aura Lake may have been found.
2. The identification of two or more separate mineralized systems explains why we have located silver rich only and gold only rocks.
These high grade surface samples are delineated in Aura's current corporate presentation available at: https://www.aurasilver.com/i/pdf/CorporatePresentation-March2012.pdf
Drilling of these targets is being planned for the 2012 field season.
Paul Pitman, P. Geo. is Aura's qualified person (as defined by National Instrument 43-101) and has reviewed and approved the scientific and technical information in this press release.
About Aura
Aura is a TSX Venture listed company engaged in the acquisition, exploration and development of precious metal prospects in Canada (100% owned Greyhound project) and in Oaxaca, Mexico (70% owned East Taviche and Alma Delia projects). Aura has 97,680,844 common shares outstanding