VANCOUVER, BC, March 4, 2010 – Mirasol Resources Ltd. (TSX-V: MRZ, Frankfurt: M8R) is pleased to announce that systematic sawn-channel sampling has returned high-grade silver values that significantly exceed previously reported average results for the Julia Vein at the Virginia Vein Zone. Best individual result from this round of sampling are 0.7 metres at 4,070 grams per ton (g/t) silver, and the best length weighted average result of 3.74 m at 1,592 g/t silver. These results confirm that Mirasol’s 100%-owned Virginia Vein Zone is rapidly developing into an important high-grade silver project.
The Virginia Vein Zone was discovered in late 2009 by Mirasol geologists while following up alteration and structural targets on newly acquired claims at Mirasol’s 100%-owned Santa Rita Project. The Virginia discovery, along with the Santa Rita Main and East silver prospects, consolidate Mirasol’s position in an emerging silver district. The nearby Lejano property, held by an unrelated party, contains an historical non-43-101 compliant inferred resource of 14 million ounces of silver.
Channel sampling of the Julia Vein reported here comprises 128 saw-cut channel samples totaling 73.88 linear metres forming 44 composite channels across outcropping vein widths (Figure 1). The length weighted average grade of all the channel samples is 796 g/t silver, which significantly exceeds the previously reported average grade of 696 g/t from 30 rock chip samples for the same vein (Feb. 16, 2010 news release). All samples have been analyzed using fire assay gravimetric method, which is considered to be a more accurate method for determining grade in strongly mineralized precious metal samples. Details of sampling procedures and calculations are available in an Appendix to this release (click here).
In at least two locations detailed mapping and sampling indicate split veins, where individual vein splits reach significant true widths with strong silver values. At one location (JU-38713) three splits are present and at another (JU-38612) two splits are present.
The average outcropping vein width recorded from this sampling is 1.88 metres and the maximum width of continuously outcropping vein is 4.3 metres. However, vein widths of at least 5.88 metres are inferred in an area where outcrop is discontinuous. Vein widths reported are considered the minimum true widths of the vein at each channel sample location (Table 1 and Figure 1), as sampling was limited to the vein itself and the margins of the vein and adjoining wall rock are not exposed. Systematic trenching or drilling will be required to accurately determine full mineralized width of the vein structures and their grades.
Channel sampling has shown strong silver mineralization over the full 2,000 metre strike length of the Julia Vein. However two segments of the vein, interpreted to represent high-grade shoots, show significantly higher silver grades and greater minimum true widths (Figure 1). The northern segment of higher grades is 520 metres in length and has been tested by 14 channels returning assays of between 324 to 2,359 g/t silver with length weighted average of all channels of 934 g/t silver over a 1.84 metre minimum true width and a maximum channel width of 5.88 metres of 1,368 g/t silver. The southern segment containing higher grades has a 260 metre strike length comprising 13 channels that assayed 317 to 1,888 g/t silver, with a length weighted average grade of 727 g/t silver over a 1.75 metre minimum true width and a maximum channel width of 3.79 metres of 904 g/t silver.
Spatially between the northern and southern segments, grades and widths vary but include the highest grade channel of 0.7m at 4,070 g/t silver. Bedrock exposure here is intermittent and the significance of these highest values is yet to be determined.
Table 1. Julia Vein Channel Samples — Compiled results
|Channel ID||Sampled Length
|Gaps as %
of Total Length
|Length Weighted Average Channels =||1.88||792||1.22|
Notes: All analyses done by ALS Chemex Laboratory, Mendoza, Argentina.
1. Sampled width is the actual true width that was sampled.
2. Unsampled gaps are the cumulative length of any gaps in outcrop which were unable to be sampled. See Technical Appendix for complete discussion.
3. Total length is the sum of the actual sampled outcrop plus any gaps which could not be sampled.
4. The length weighted silver, gold and lead averages are based on the sampled width not the total length and all values are uncut (i.e. no grade capping has been applied)
5. Silver results are by Ag-GRA21, a fire assay collection method with gravimetric finish
6. Lead results to 10,000 ppm (1%) are by ME-ICP41 with over values >1% by Pb-OG46
7. Channels so marked have sampling gaps greater than 20% of their total length. See Technical Appendix for complete discussion.
8. Gold by Au-AA24, a fire assay collection method with atomic absorption spectroscopy finish
Gold values for the channels range from <0.05 g/t to a maximum of 0.31 g/t over 1.62 metres with a length weighted average of 0.03 g/t gold.
Stephen Nano, Mirasol’s vice president stated “The systematic saw cut channel sampling of outcrops along the Julia Vein has delivered high-quality samples that give a reliable measure of the outcrop silver grades. The continuity of high-grade silver along the vein and the recognition of potential for higher grade (bonanza) shoots are considered to be a significant step toward the definition of drill targets at this project”.
Mapping and sampling at the Virginia Vein Zone continues to reveal new veins and extend the strike length of mineralized structures, which combined now total more than 4,000 metres of strike length. Recently reported rock chip results (news release February 16, 2010) confirm that most of these veins are also well mineralized with silver. Mirasol’s management is pleased to add a high caliber project such as the Virginia Vein Zone to the Company’s portfolio of precious metal projects in Santa Cruz Province and looks forward to reporting further developments at the project.
Paul G. Lhotka, Principal Geologist for Mirasol, is the Qualified Person under NI 43-101 who has approved the technical content of this news release.
For further information, contact:
Quality Assurance/Quality Control:
Exploration at Mirasol’s Projects is supervised by Stephen C. Nano, Vice President of Exploration; Exploration Manager, Timothy Heenan; and Principal Geologist, Paul Lhotka, all qualified persons under NI 43-101. All technical information for the Company’s projects is obtained and reported under a formal quality assurance and quality control (QA/QC) program. Rock chip and stream sediment samples are collected under the supervision of Company geologists in accordance with standard industry practice. Samples are dispatched via commercial transport to an ISO 9001:2000-accredited laboratory in Mendoza, Argentina for analysis. Results are routinely examined by an independent geochemist to ensure laboratory performance meets required standards.
All assay results reported herein are for surface rock chip samples; assay results from subsurface drill core or RC samples may be higher, lower or similar to results obtained from surface samples.
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