Mr. Guoliang Ma reports
SILVERCORP REPORTS HIGH-GRADE MINERALIZATION DISCOVERY BELOW CURRENT PRODUCTION LEVELS WITHIN MAJOR VEIN STRUCTURES AT GC AG-PB-ZN MINE IN GUANGDONG PROVINCE, CHINA
Silvercorp Metals Inc. has released results of its 2016 and 2017 exploration program at its GC Ag-Pb-Zn (silver-lead-zinc) mine, Guangdong province, China.
In 2016 and 2017, the company launched extensive exploration program and completed a total of 33,029 metres of underground diamond drilling and 19,619 m of exploration tunnelling at its GC Ag-Pb-Zn mine. Significant high-grade mineralized zones have been exposed at and below the current production levels, and major mineralized zones have been extended along strike and downdip.
The drilling program included infill drilling to define and upgrade the current resource model, and stepout drilling for new resources surrounding and below the current resource area. Between 2016 and 2017, 294 NQ-sized diamond drill holes with total length of 33,029 metres were accomplished at seven production levels from 150 m to minus 200 m at 50 m interval (the elevation of the head frame is 258.5 m). Among them, 153 holes intersected ore veins with Ag equivalent (AgEq) values greater than 194 g/t, and another 36 holes hit mineralized veins with AgEq values between 97 and 194 g/t.
SUMMARY OF THE DRILLING PROGRAMS IN 2016 AND 2017
Holes Holes
Year Metres Holes Samples intercepted intercepted
drilled completed collected mineralization ore
2016 11,878 129 2,235 29 77
2017 21,151 165 4,595 7 76
Total 33,029 294 6,830 36 153
In 2016 and 2017, 19,619 m of tunnelling were driven along and across the major mineralized vein structures to upgrade the resource model and test for new vein structures. These included 7,767 m key drifts that exposed 4,803 m of ore veins, as well as 4,351 m of key raises that exposed 3,002 m of ore veins.
SUMMARY OF THE TUNNELLING PROGRAMS IN 2016 AND 2017
Samples Key drifts Ore exposed Key raise Ore exposed
Year Tunnelling collected included in drifts included in raises
(m) (m) (m) (m) (m)
2016 9,152 4,063 2,482 1,980 1,683 1,266
2017 10,467 5,608 5,285 2,823 2,668 1,736
Total 19,619 9,671 7,767 4,803 4,351 3,002
The associated tables list assay results of some selected drill holes that intercepted ores and drift tunnels that exposed ore zones in the 2016 and 2017 exploration programs.
SELECTED DRILLING RESULTS FROM THE 2016 AND 2017 DRILLING PROGRAMS AT GC MINE
Year Hole From To True width Ag Pb Zn AgEq (1) (2)
ID (m) (m) (m) (g/t) (%) (%) (g/t)
2016 CK10381 29.97 32.74 2.54 97 0.11 9.65 590
2016 CK10582 85.74 89.84 2.84 78 2.66 3.21 383
2016 CK11201 17.44 19.65 2.02 233 4.68 2.30 601
2016 CK11301 11.68 27.51 8.64 48 2.03 6.08 464
2016 CK3086 0 8.2 6.39 90 0.62 1.69 209
2016 CK3087 0 6.27 3.58 134 1.48 4.01 416
2016 CK4083 82.22 87.6 4.48 45 1.24 3.53 290
2016 CK4083 103.44 109.69 5.20 49 0.91 2.07 203
2016 CK4084 50.88 60.04 7.35 43 0.89 3.87 286
2016 CK4280 17.25 21.71 3.48 45 1.69 5.65 421
2017 18CK26A04 126.59 132.08 3.77 72 0.91 3.72 309
2017 18CK26A05 277.32 281.96 3.31 171.2 1.99 5.12 537
2017 18CK28A05 295.05 297.97 1.97 310 2.13 14.69 1,167
2017 CK10586 114.16 116.39 1.61 491 0.69 5.63 813
2017 CK10588 33.11 37.23 2.83 87 3.12 2.62 387
2017 CK10691 99.57 102.38 2.14 191 3.68 3.09 545
2017 CK1080 83.13 84.28 1.11 758 1.97 2.98 1,015
2017 CK10982 117.35 128.37 6.51 55 2.02 3.55 343
2017 CK10986 97.06 100.35 3.23 94 0.46 5.95 419
2017 CK2282 56.56 60.64 3.90 57 1.21 6.52 451
2017 CK2688 115.76 123.59 7.57 64 0.75 4.00 306
2017 CK26A84 135.49 138.33 2.56 92 1.58 5.74 467
2017 CK26A88 106.15 108.95 2.79 109 4.59 5.29 624
2017 CK26A88 128.67 134.78 5.53 58 0.82 5.65 388
2017 CK28A84 116.96 120.93 3.47 299 3.00 10.54 993
2017 CK28A84 143.19 152.1 7.79 143 3.58 4.08 542
2017 CK28A86 96.95 97.89 0.77 932 5.83 5.05 1,501
2017 CK30A83 184.5 191.15 5.01 101 0.90 2.89 295
(1) Metal prices assumed: silver $19 (U.S.)/ounce, lead $1.0 (U.S.)/pound, zinc
$1.2 (U.S.)/pound.
(2) Ag equivalent: AgEq -- Ag grade (g/t) plus 53.9 times Pb grade (%) plus 50.5
times Zn grade (%).
SELECTED DRIFTS THAT EXPOSED ORE ZONES AT GC MINE IN 2016 AND 2017
Drift Length True width Ag Pb Zn AgEq
ID (m) (m) (g/t) (%) (%) (g/t)
V2W-(-150)-22YM 128 1.89 132 2.77 3.48 457
V2W-(-150)-22AYM+CM 54 8.00 132 3.12 4.63 534
V2E-(-150)-26EYM 300 1.70 134 2.85 3.89 484
V2E-(-200)-28EYM 117 2.69 99 1.25 4.19 379
-150-V2E1-26YM 86 5.99 96 0.66 1.78 221
V2E1-(-200)-26AYM 71 2.70 163 2.18 2.79 421
V7E(V36)-(-100)-40YM 110 1.75 106 2.14 4.04 426
V9-5-(-150)-30WYM 150 1.45 96 3.41 3.57 461
-100-V10-40AYM 210 1.29 41 1.29 3.34 280
V10-1-0-42SYM 145 1.57 101 0.86 4.16 357
V14-50-(105-111)YM 163 0.83 129 1.93 6.15 544
-100-V16-22AYM 208 1.73 44 0.48 2.75 209
V24-0-14SWYM 90 1.10 312 2.63 5.81 747
The stepout drilling and tunnelling in the east of the mine defined new mineralized vein structures including V7E, NV10, V14, V19, V31, V32 and V33. Vein V7E has been defined 95 m in strike length, 150 m in downdip length and 0.8 to 1.75 m in width, with average grade of 81 g/t Ag, 1.43 per cent Pb and 3.08 per cent Zn. The exploration program at minus 150 m and minus 200 m levels indicated that the length and width, ore continuity, and ore grades improved greatly with the increase of depth.
INCREASES OF AVERAGE GRADES IN VEINS V2E AND V2W WITH DEPTH
Vein Level Length True width Ag Pb Zn AgEq
(m) (m) (m) (g/t) (%) (%) (g/t)
V2E 100 30 1.52 212 1.42 0.59 318
50 164 1.24 71 1.73 2.83 307
0 229 1.02 74 1.32 2.40 266
-50 225 1.2 94 1.47 2.62 306
-100 450 1.48 105 1.33 2.80 318
-150 418 1.28 122 1.94 3.35 396
-200 400 1.92 126 2.10 3.82 432
V2W 100 77 3.57 100 0.15 2.20 219
50 174 2.15 118 0.83 3.91 360
0 106 3.03 139 1.71 3.38 402
-50 242 3.4 141 1.62 3.48 404
-100 128 2.19 120 1.39 2.51 322
-150 183 6.32 277 5.00 6.53 876
In addition, two drill holes, 18CK26A04 and 18CK28A05, hit high-grade mineralization with true widths of 3.31 m and 1.97 m, respectively, at elevation around minus 455 m. The host rock of the mineralization is slate, which indicated that the mineralization system is not limited to granite, but extends into the sedimentary rock underneath the granite intrusive. Also, the trend of increasing Ag, Pb, Zn and Cu grades with depth continued to below minus 450 m elevation. The assay results of the intercepted ore of drill hole 18CK28A05 are 310 g/t Ag, 2.13 per cent Pb, 14.96 per cent Zn, 0.73 per cent Cu, 0.19 per cent Sn and 0.34 g/t Au.
Quality control
Drill core samples were taken from sawn half core for every 1.5 m or limited by apparent wall rock and mineralization contact. Half of the core was sent to the laboratory for analysis and the other half retained for archive. The channel samples are collected along sample lines perpendicular to the mineralized vein structure in exploration tunnels. Sample length ranges from 0.2 m to more than 1.0 m, depending on the width of the mineralized vein and the mineralization type. Spacing between sampling lines is typically five m along strike. Both the mineralized vein and the altered wall rocks are cut with continuous chisel chipping. The samples are individually secured in cotton sample bags and then collectively secured in rice bags for shipment to the on-site laboratory.
For analysis, the sample is dried and crushed to minus one millimetre and then split to a 200 to 300 g subsample which is further pulverized to minus 200 mesh. A duplicate sample of minus one mm is made and kept at the laboratory archives. Two subsamples are prepared from the pulverized sample. One is digested with two acids for analysis of silver, lead, zinc and copper with atomic absorption spectroscopy. The other is retained as pulp reject at the lab for future reference.
A routine quality assurance/quality control (QA/QC) procedure is adopted to monitor the analytical quality at the lab. Certified reference materials (CRMs), pulp duplicates and blanks are inserted into each lab batch of samples. QA/QC data at the lab are attached to the assay certificates for each batch of samples.
The company maintains its own comprehensive QA/QC program to ensure best practices in sample preparation and analysis of the exploration samples. Project geologists regularly insert CRM, field duplicates and blanks to each batch of core samples to monitor the sample preparation and analysis procedures at the labs. The analytical quality of the labs is further evaluated with external checks by sending about 3 to 5 per cent of the pulp samples to higher-level labs to check for lab bias.
Data from both the company's and the lab's QA/QC programs are reviewed on a timely basis by project geologists.
Guoliang Ma, PGeo, Silvercorp's manager of exploration and resource, reviewed the exploration data and prepared the scientific and technical information regarding exploration results contained herein. He is the qualified person on the project as defined under National Instrument 43-101 and has verified and approved the contents of this news release.
About Silvercorp Metals Inc.
Silvercorp is a low-cost silver-producing Canadian mining company with multiple mines in China. The company's vision is to deliver shareholder value by focusing on the acquisition of underdeveloped projects with resource potential and the ability to grow organically.
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