Mirasol reports highest grade silver yet from the La Negra zone at Joaquin with 25.4 metres of 1,164 g/t silver
VANCOUVER, BC, November 24, 2009 – Mirasol Resources Ltd. (TSX-V: MRZ, Frankfurt: M8R) is pleased to announce partial results from the third phase of drilling from the La Negra zone at Mirasol’s Joaquin Project. These results include the highest grade intercept drilled to date at Joaquin comprising 25.4 meters of 1,164 grams per tonne (g/t) silver and 0.21 g/t gold including a very high grade interval of 3.3 metres of 7,753 g/t silver and 1.17 g/t gold. The Joaquin project is located in the province of Santa Cruz, southern Argentina, which is host to four operating precious metal mines.
Mirasol’s Joint venture partner Coeur d’ Alene Mines Corporation (“Coeur”) is conducting the third phase of exploration drilling at Joaquin, and has completed 1,786.6 metres in nine diamond holes at the La Negra zone before moving the drill to the La Morocha target.
This announcement presents the results received to date from five new La Negra holes (DDJ 39 – 43), as well as new assay results for previously unsampled upper intervals of holes DDJ- 36 and DDJ-37 from the second phase of drilling (see press release July 23, 2009), all shown in Table 1.
Best down hole intersections returned from this round of results at a 20 g/t silver equivalent cut-off are: from DDJ-37, 32.2 metres of 164 g/t silver and 0.08 g/t gold, including 4.7 metres of 767 g/t silver and 0.27 g/t gold; from DDJ-39, 43.3 metres of 119 g/t silver and 0.11 g/t gold, including 0.9 metres of 1,939 g/t silver and 0.62 g/t gold; and from DDJ-43, 25.4 metres of 1,164 g/t silver and 0.21 g/t gold including a high grade interval of 3.3 metres of 7,753 g/t silver and 1.17 g/t gold.
Coeur continues to drill La Negra on 100 metre spaced sections with holes spaced at 50 to 100 metre drill centers (see Figure 1). Despite wide-spaced drilling, all holes reported to date have encountered significant silver mineralization at a 20 g/t silver equivalent cutoff.
At the La Negra zone, mineralized intersections outline a 700 metre long corridor which is open down dip and along strike that ranges from 20 metres to as much as 150 metres in width. Within this corridor multiple parallel zones of mineralization exist at a greater than 20 g/t silver equivalent cutoff (see Figure 2). In some cases more than half of the width of the known corridor is above the 20 g/t cutoff. The dips of the individual mineralized intercepts have not been calculated because the wide-spaced drilling does not yet allow confident correlation of the individual intercepts between holes. The overall dip of the corridor and zones appears to range from near vertical to steeply northeast, thus true widths of the mineralized intercept are likely to be between 65 and 80 percent of the intercept lengths reported.
Mineralization is associated with clay alteration, barite and locally silica, all occurring as replacements, breccia matrix infill, and veinlets which cut the host volcanic tuffs. In most cases the mineralization appears oxidized and few remnant sulphides are visible. In contrast, the high grade mineralization in hole DDJ-43 comprises a clay-rich shear zone with abundant fresh sulphides including pyrite, base metal sulphides and probably the silver mineral argentite, based on visual examination. In general, the La Negra holes have insignificant base metal values where base metal assays have been performed.
Hole DDJ-43 confirms that in addition to the previously identified larger volumes of lower grade mineralization which may be amenable to bulk-mining that La Negra contains zones of very high-grade silver mineralization.
Table 1. Joaquin Project — La Negra Prospect New Drill Results
Drill Hole |
Intercept | From (metres) |
To (metres) |
Intercept length (metres) |
Core Recv. (%) |
Ag (g/t) |
Au (g/t) |
AgEQ (g/t) |
DDJ-36 | 1st | 10.8 | 24.2 | 13.4 | 89 | 101 | 0.07 | 105 |
including | 13.7 | 23.4 | 9.7 | 88 | 131 | 0.05 | 134 | |
including | 13.7 | 16.0 | 2.3 | 78 | 384 | 0.06 | 388 | |
DDJ-37 | 1st | 7.0 | 39.2 | 32.2 | 96 | 164 | 0.08 | 169 |
including | 18.3 | 23.0 | 4.7 | 96 | 767 | 0.27 | 785 | |
including | 28.1 | 33.0 | 4.9 | 96 | 199 | 0.07 | 203 | |
DDJ-39 | 1st | 26.7 | 50.8 | 24.1 | 82 | 129 | 0.08 | 134 |
including | 27.3 | 30.0 | 2.7 | 53 | 952 | 0.58 | 989 | |
DDJ-39 | 2nd | 75.8 | 119.1 | 43.3 | 90 | 119 | 0.11 | 127 |
including | 76.7 | 77.6 | 0.9 | 95 | 1,939 | 0.62 | 1,979 | |
including | 87.5 | 95.2 | 7.8 | 87 | 114 | 0.20 | 127 | |
including | 101.5 | 107.0 | 5.5 | 87 | 148 | 0.13 | 157 | |
including | 111.0 | 119.1 | 8.1 | 96 | 152 | 0.08 | 157 | |
DDJ-39 | 3rd | 185.8 | 242.0 | 56.2 | 90 | 69 | 0.09 | 75 |
including | 215.7 | 230.4 | 14.7 | 88 | 159 | 0.16 | 170 | |
DDJ-40 | 1st | 71.5 | 73.5 | 2.0 | 83 | 254 | 0.03 | 256 |
DDJ-40 | 2nd | 99.7 | 102.4 | 2.7 | 93 | 60 | 0.06 | 64 |
DDJ-40 | 3rd | 204.0 | 215.2 | 11.2 | 96 | 34 | 0.47 | 65 |
including | 207.0 | 212.0 | 5.0 | 97 | 45 | 0.78 | 96 | |
DDJ-40 | 4th | 243.1 | 263.5 | 20.5 | 81 | 105 | 0.30 | 124 |
including | 251.4 | 260.0 | 8.6 | 94 | 191 | 0.25 | 207 | |
DDJ-41 | 14.0 | 32.0 | 18.0 | 98 | 42 | 0.06 | 46 | |
including | 14.0 | 15.0 | 1.0 | 100 | 414 | 0.10 | 420 | |
DDJ-42 | 1st | 65.0 | 88.0 | 23.0 | ** | 22 | 0.05 | 25 |
including | 86.0 | 88.0 | 2.0 | ** | 100 | 0.02 | 102 | |
DDJ-42 | 2nd | 104.0 | 107.7 | 3.7 | ** | 400 | 0.02 | 402 |
DDJ-43* | 18.0 | 43.4 | 25.4 | ** | 1,164 | 0.21 | 1,178 | |
including | 22.2 | 25.5 | 3.3 | ** | 7,753 | 1.17 | 7,829 |
* Assays from hole DDJ-43 are pending results of additional check assays.
** Core recovery information not available at this time.
– Silver equivalent is calculated as AgEQ g/t = Ag g/t + 65 x Au g/t. The silver equivalent grade is calculated before consideration for metallurgical recoveries.
– Primary intersections are calculated at a cutoff grade of 20 g/t silver equivalent (AgEQ) with some internal dilution allowed at the discretion of the project’s Qualified Person.
– “Included” intersections are calculated at a 50 g/t or higher cutoff grade.
– Reported grades are not capped.
– Estimated true widths have not been calculated but are estimated to be between 65 and 80 percent of the core lengths reported.
– Coeur has previously released results for holes DDJ-39, 40 and 41, using a 10 g/t AgEQ cutoff which resulted in similar, but not identical, mineralized intercepts reported in their disclosure.
Check assays are currently being performed on high-grade material in DDJ-43 at a second laboratory.
Mirasol’s management is encouraged that the results received to date from the third phase of drilling continue to expand the strike extent of the La Negra mineralization and confirm the presence of bonanza-grade silver within broader zones of lower-grade, potentially bulk-mineable mineralization. Mirasol Resources is pleased to be evaluating this project with Coeur d’Alene, who brings to the joint venture significant experience in the exploration and development of epithermal precious metal mineralization in the region.
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:
Mary L. Little
President and CEO
Tel: (604) 602-9989: Fax:(604) 609-9946
Email: contact@mirasolresources.com
Website: www.mirasolresources.com
Quality Assurance/Quality Control: Coeur d’Alene operates the Joaquin Joint Venture and generated the drilling data used in this news release and reported it to Mirasol. Drill core samples were submitted to Alex Stewart (Assayers), Argentina S.A. in Mendoza, Argentina. Gold and silver results were determined using standard fire assay techniques on a 50 gram sample with an atomic absorption finish for gold and a gravimetric finish for silver. Coeur’s QAQC program includes the insertion of blanks and standards into the sample stream on all Joaquin drill holes. For Phase three it has added duplicate core samples as part of the QAQC program. Mirasol has performed an independent analysis of the QAQC data generated by Coeur. Dr. Paul Lhotka has reviewed the Coeur data, calculated the intercepts in this news release, and is a qualified person as defined by National Instrument 43-101.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.