EXPLORATION – Juanicipio Project
MAG Silver owns 44% of Minera Juanicipio S.A. de C.V. ("Minera Juanicipio"), a Mexican incorporated joint venture company, which owns the high-grade Juanicipio Property, located in the Fresnillo District, Zacatecas State, Mexico. Both exploration and development of the Juanicipio Property are being carried out by the project operator, Fresnillo plc ("Fresnillo"), which holds the remaining 56% interest in the joint venture. The major asset associated with the Juanicipio Property is a high-grade silver-gold-lead-zinc epithermal vein deposit. The primary vein, the Valdecañas Vein, is an en echelon system comprised of overlapping East and West Veins and several smaller vein splays (the term "Valdecañas Vein" is used to refer to this en echelon system).
Exploration and development programs for the Juanicipio Property are designed by the Minera Juanicipio Technical Committee, and approved by the Minera Juanicipio Board of Directors. The Company's share of costs is funded primarily through its 44% interest in Minera Juanicipio, and to a lesser extent, incurred directly by the Company to cover expenses related to parallel technical studies and analyses commissioned by the Company, as well as direct project oversight. Minera Juanicipio is governed by a shareholders agreement and corporate by-laws, pursuant to which each shareholder is to provide funding pro rata to its interest in Minera Juanicipio.
Exploration drilling continued in the quarter ended September 30, 2019. To date in 2019, 29 drill holes have been completed, 21 being infill holes and 8 exploration holes as part of a 25,000 metre 2019 exploration program which was completed subsequent to the September 30, 2019 quarter end (all assays pending). The 2019 drilling has primarily been directed at infilling the few remaining gaps in the Indicated Resources in the Bonanza Zone, converting Inferred Resources included in the Deep Zone into Indicated Resources, and further tracing the Deep Zone laterally and to depth. Five holes were also directed at the recently discovered Venadas Vein.
Assays from 48 previously completed holes (46,060 metres) were reported in the first quarter of 2019 (see Press Release dated March 4, 2019).
Valdecañas Deep Zone expanded and significant new hangingwall vein discovered
The March 4, 2019 drill results extend and confirm continuity to depth of high-grade mineralization in the East and West Valdecañas Vein Deep Zones and in the Anticipada Vein. Drilling also coincidentally discovered the new Pre-Anticipada vein in the eastern hangingwall above the system. Drill holes in the eastern end of the Valdecañas Vein now cut two hangingwall veins before reaching the main Valdecañas Vein.
DEEP ZONE WEST: Infill Hole P22: 11.6 m (true width) grading 783 g/t (22.9 opt) silver, 2.57 g/t gold, 6.52% lead, 9.46% zinc, 0.32% copper.
DEEP ZONE EAST: Step-Out Hole P26: 6.3m (true width) grading 246 g/t (7.2 opt) silver, 1.78 g/t (capped) gold, 7.20% lead, 11.63% zinc, 0.40% copper.
ANTICIPADA VEIN: Infill Hole P24-1: 6.2 m (true width) grading 275 g/t (8 opt) silver, 4.02 g/t gold, 7.28% lead, 9.24% zinc and 0.30% copper.
NEW DISCOVERY — "PRE-ANTICIPADA VEIN”: Step-out Hole P28: 3.2 m (estimated true width) grading 472 g/t (13.8 opt) silver, 0.31 g/t gold, 0.39% lead, 0.43% zinc and 0.03% copper.
Since the discovery of the Deep Zone as an extension at depth of the high-grade Bonanza Zone (see Press Release April 23, 2015), the Valdecañas Vein System has emerged as a multi-stage, high-grade vein swarm comprising the overlapping East and West Veins, the hangingwall Anticipada Vein, the newly discovered Pre-Anticipada Vein and several other splays. The latest holes include the deepest lateral intercepts to date on the Valdecañas Vein, with deep mineralization now traceable continuously over a strike length exceeding 2,000 m and up to 1,100 m vertically from the top of the Bonanza Zone. Vein widths range from approximately 2 m to over 29 m. Deep mineralization on the Valdecañas Veins remains open laterally for several hundred metres to the claim boundaries on both ends; to the east claim boundary for Anticipada; and Pre-Anticipada and to depth across all veins (see http://www.magsilver.com/s/NewsReleases.asp?ReportID=846343 for diagrams).
Notably, the Valdecañas deep zones continue to demonstrate atypically high silver grades that MAG believes are ascribable to stacking or superimposition of a later mineralization stage related to a deeper, fluctuating boiling zone. Zinc and lead increase at depth as normally expected in the “root zone” of an epithermal vein, but copper grades are locally very high at depth, along with boron and high-temperature alteration minerals. Gold grades remain high and remarkably consistent from top to bottom. These phenomena, as interpreted, reflect proximity to a major mineralizing-fluid upwelling zone where multiple repeated pulses of mineralization combined to generate exceptionally high-grade polymetallic mineralization.
Valdecañas Vein West
Eleven new intercepts on the Valdecañas Vein West were also reported on March 4, 2019 (See Table of drill assays here). Three fall within the Deep Zone Mineral Resource estimate and reinforce those results. The best is Hole P22, which cut 11.6 m (true width) grading 783 g/t (22.9 opt) silver, 2.57 g/t gold, 6.52% lead, 9.46% zinc, 0.32% copper in the heart of the Dilatant Zone (See Press Releases dated August 15, 2016 and February 14, 2017). Three more intercepts are high in the system and confirm the upper limits of the mineralized envelope (see “Shallow Holes” discussion below). The remaining five intercepts are 100 m step-outs designed to extend the resource envelope, the best being Hole P21, the westernmost deep hole on the Valdecañas Vein West. P21 cut 9.8 m (true width) grading 84 g/t (2.5 opt) silver, 2.74 g/t gold, 2.95% lead, 1.89% zinc, 0.11% copper. At the eastern extreme of this zone, Hole D6-1 cut 3.8 m (true width) grading 359 g/t (10.5 opt) silver, 0.09 g/t gold, 0.96% lead, 2.31% zinc, 1.68% copper. The Valdecañas West Deep Zone remains open to depth and laterally, especially to the southwest towards the claim boundary, which lies 200 - 300 m farther west.
Valdecañas Vein East
Twenty-four new intercepts were reported on March 4, 2019 from the Valdecañas Vein East (See Table of drill assays here). Six fall within the boundary of the Deep Zone Mineral Resource estimate and reinforce those results. The best of these is Hole TIV, which cut 4.8 m (true width) grading 278 g/t (8.1 opt) silver, 1.78 g/t gold (capped), 4.88% lead, 10.48% zinc, and 1.20% copper. Five more intercepts are high in the system and confirm the upper limits of the mineralized envelope. (see “Shallow Holes” discussion below). The remaining thirteen intercepts were 50 – 100 m step-outs designed to extend the Deep Zone Mineral Resource estimate envelope. Eight cut strong mineralization with the best being Hole P26, drilled under the middle of the zone, which cut 6.3 m (true width) grading 246 g/t (7.2 opt) silver, 1.78 g/t gold (capped), 7.20% lead, 11.63% zinc, 0.40% copper. Overall the Valdecañas East Deep Zone remains open to depth and laterally, especially in the middle; but it does appear to weaken towards the east at these depths. Hole VM-11 is an isolated hole drilled 200 m below the base of the Deep Zone Mineral Resource estimate. It hit thick but relatively weak mineralization in the Valdecañas Vein but did cut very strong mineralization in the Anticipada about 120 m uphole (see ‘Anticipada Vein “VANT”’ below).
Anticipada Vein “VANT”
Fourteen of the reported holes coincidentally cut the Anticipada Vein 50 to 100m before reaching their primary target: the Valdecañas Vein East Deep Zone (See Table of drill assays here). Seven fall within the boundary of the Deep Zone Mineral Resource estimate and significantly expand this vein, especially in a vertical zone along its western reaches. The best of these is Hole P24-1, which cut 6.2 m (true width) grading 275 g/t (8 opt) silver, 4.02 g/t gold, 7.28% lead, 9.24% zinc and 0.30% copper. The remaining seven holes were 50 to 100m step-outs that served to test the limits of the Deep Zone Mineral Resource estimate mineralized envelope. The three easterly intercepts show relatively weak mineralization but the four westernmost holes extend the strong vertical zone of high-grade mineralization mentioned above. The deepest of these (VM-11) cuts about 150m below the bottom of the Anticipada Vein and reported 2.0 m (true width) grading 146 g/t (4.3 opt) silver, 0.12 g/t gold, 2.40% lead, 17.32% zinc and 0.64% copper. This is the deepest and westernmost intercept in the Anticipada Vein, which remains open to depth and for several hundred metres towards the eastern property limit.
Pre-Anticipada Vein (2019 Discovery)
Sixteen of the holes that cut the Anticipada Vein on their way to the Valdecañas Vein East Deep Zone also encountered the previously unknown Pre-Anticipada Vein 50 - 100 m farther into the hangingwall (See Table of drill assays and figures here). The easternmost four appear to form a coherent zone with significant width and grade which is open 200 – 300 m to the east property boundary and to depth. The best hole is Hole P28, which cut 3.2 m (estimated true width) grading 472 g/t (13.8 opt) silver, 0.31 g/t gold, 0.39% lead, 0.43% zinc and 0.03% copper. Notably, Hole P19, 50 m deeper to the west reported 1256 g/t (36.7 opt) silver, a remarkable silver value for this depth in the system. Overall, the results for Pre-Anticipada show strong silver values with the best intercepts lying at an elevation between the base of the Bonanza Zone and the top of the Dilatant Zone of the Valdecañas Vein East Deep. These holes also report very low base metal values indicating a high-level position relative to the epithermal vein zoning model. It is possible that Pre-Anticipada represents mineralization related to the postulated deeper boiling zone emplaced into a structure separate from those that host the base metal rich roots of the earlier mineralization stage.
Both the Pre-Anticipada and Anticipada Veins are open to depth and for 200-300 m eastward to the property boundary.
Five holes (SA-1 to 4 and D8-1) were reported that were drilled to refine the upper limits of the Bonanza Zone in both the East and West Valdecañas veins. As expected, all five hit relatively narrow, silver-dominant mineralization except Hole SA-4 which cut 1.7 m (true thickness) grading 4341 g/t (126 opt) silver, 1.03 g/t gold, 3.14% lead, 5.81% zinc, 0.09% copper in the East Vein.
Venadas Vein discovery - New Juanicipio exploration potential
The discovery of the new Venadas Vein was also reported on March 4, 2019. The Venadas Vein is believed by the Company to be the first ever mineralized vein in the Fresnillo district oriented at a high angle (NE) to the historically mined northwest (“NW”) oriented veins. The NE-oriented Venadas Vein was inferred from the alignment of fifteen previously unconnected intercepts (See Table and Figures at http://www.magsilver.com/s/NewsReleases.asp?ReportID=846344) before being cut in an underground development working as a 1.1 m wide vein, reporting 116 g/t (3.4 opt) silver, 3.16 g/t gold. Hole VEN-1, the first drill hole specifically designed to test the Venadas Vein, cut 3.0 m (drilling width) grading 392 g/t (11.5 opt) silver and 5.54 g/t gold. All intercepts contain negligible base metals and lie above 1,750 m elevation, with most significantly higher than the top of the Valdecañas Vein at 1850 m elevation. This indicates a very high-level overall position in the vein zoning model, suggesting that Venadas has considerable depth potential.
Notably, other much larger NE structures with intense surface alteration are known farther afield within the Juanicipio property and are now priority exploration targets. None have ever been directly drilled.
Quality Assurance and Control: The samples (half core) are shipped directly in security-sealed bags to ALS-Chemex Laboratories preparation facility in Guadalajara, Jalisco, Mexico (Certification ISO 9001). Samples shipped also include intermittent standards and blanks. Pulp samples are subsequently shipped to ALS-Chemex Laboratories in North Vancouver, Canada for analysis. Two extra pulp samples are also prepared and are analyzed (in progress) by SGS Laboratories (Certification ISO 9001) and Inspectorate Laboratories (Certification ISO 9001) (or another recognized lab). The remaining half core is placed back into the core boxes and is stored on site with the rest of the drill hole core in a secured core storage facility. The bulk reject is subsequently sent to CIDT (Center for Investigation and Technical Development) of Peñoles in Torreon, Mexico for metallurgical testing where a fourth assay for each sample is analyzed and a calculated head grade is received on the basis of a concentrate balance. The CIDT also does a full microscopic, XRF and XRD mineralogical analysis.