Silvercorp Continues to Intersect High-Grade Silver-Lead Zones at the TLP Mine
Trading Symbol: TSX: SVM
NYSE AMERICAN: SVM
VANCOUVER, British Columbia – July 17, 2023 – Silvercorp Metals Inc. (“Silvercorp” or the “Company”) (TSX: SVM) (NYSE American: SVM) is pleased to report high-grade silver-lead intercepts from its ongoing diamond drilling program at the TLP mine at the Ying Mining District, China.
Highlights (all intersections are in core lengths):
- Surface hole ZKTDB0413 intersected 1,025 grams per tonne (“g/t”) silver (“Ag”), 3.01% lead (“Pb”), and 0.11 g/t gold (“Au”) over a 2.48 metre (“m”) interval of vein T26 at the 1,113 m elevation;
- Surface hole ZKTDB2005 intersected 3,211 g/t Ag, 2.41% Pb, 0.15% zinc (“Zn”), and 0.16% copper (“Cu”) over a 0.63 m interval of vein T1E at the 1,129 m elevation;
- Surface hole ZKTDB0501 intersected 312 g/t Ag, 3.21% Pb, and 0.43% Zn over a 5.04 m interval of vein T2 at the 980 m elevation;
- Hole ZKG0847 intersected 8,254 g/t Ag, 11.71% Pb, and 1.30% Zn over a 1.87 m interval of vein T16 at the 684 m elevation;
- Hole ZKG1447 intersected 7,140 g/t Ag, 30.79% Pb, 0.92% Zn, and 1.43% Cu over a 0.57 m interval of vein T15W2 at the 818 m elevation;
- Hole ZKG0325 intersected 3,475 g/t Ag, 2.22% Pb, 1.52% Zn, and 0.75 g/t Au over a 0.86 m interval of vein T38 at the 752 m elevation;
- Hole ZKT4710 intersected 83 g/t Ag, 10.46% Pb, 0.46% Zn, 0.09 g/t Au, and 0.75% Cu over a 6.26 m interval of vein T3 at the 638 m elevation;
- Hole ZKG1024 intersected 2,743 g/t Ag, 6.95% Pb, and 1.67% Zn over a 1.27 m interval of vein T11 at the 630 m elevation;
- Hole ZKG1437 intersected 2,204 g/t Ag, 5.13% Pb, 0.43% Zn, and 0.51% Cu over a 2.08 m interval of vein T16 at the 749 m elevation;
- Hole ZKG1441 intersected 3,437 g/t Ag, 2.09% Pb, 1.55% Zn, and 0.22% Cu over a 1.20 m interval of vein T16 at the 727 m elevation;
- Hole ZKT0829 intersected 453 g/t Ag, 5.10% Pb, and 0.93% Zn over a 4.60 m interval of vein T14E at the 975 m elevation; and
- Hole ZKG0009 intersected 542 g/t Ag, 52.01% Pb, 0.20% Zn, and 0.16% Cu over a 0.81 m interval of vein T15W at the 637 m elevation.
From January 1, 2022, to June 15, 2023, a total of 66,679 m in 340 diamond drill holes, including 270 underground holes and 70 surface holes, were completed at the TLP mine. Assay results for 227 holes have been received, with 197 holes intersecting mineralization. Currently, there are 10 rigs drilling at the TLP mine.
The drilling program has targeted three areas: 1) silver-lead vein structures in the resource area at higher elevations, close to surface, which have seen limited exploration; 2) infilling in the production area, particularly above or below previously-mined stopes, where production stopped due to higher than modelled variability in grades, thicknesses, and attitudes of the vein structures; and 3) step out drilling to test the extension of the major vein structures to the northeast of the resource area.
Drilling Near-Surface Ag-Pb Vein Structures within the Resource Area
Drilling over the past few years primarily focused on the lateral and downdip extent of known vein structures and paid insufficient attention to their extension potential at elevations above 900 m. In addition to the 70 surface drill holes, which account for over 20% of the drill holes in this program, many underground holes drilled also targeted the vein structures at higher elevations. High-grade Ag-Pb vein structures intersected at higher elevations include the T1 series, T2, T3 series, T11 series, T14E, T15 series, T16 series, T23 series, and T26 series (Table 1).
Drilling Above or Beneath Previously-Mined Stopes within the Resource Area
Most holes drilled during this period targeted blocks of known Ag-Pb vein structures that were previously missed due to limited drilling or tunneling, changes in thickness, strikes and dips of the pay-zones in veins within the resource areas below the 900 m elevation. The high-grade intercepts are mainly associated with the northwest-dipping T1 series, T2 series, T3 series, T4, T11 series, T15 series, T16 series, T23 series, T20, T21, T31W3, T33 series, and T35 series, and the east-dipping T14 series, T22 series, T26 series, and T28 series. These intercepts have led to significant expansion and upgrading of resources. Since the ramps and access tunnels are already in place, these defined high-grade blocks can be quickly converted to reserves and mined.
Step-Out Drilling Intersecting Ag-Pb Veins to the Northeast of the Resource Area
Step-out surface and underground drilling intersected high-grade Ag-Pb veins T2, T3 series, T4, T5, and T21 series to the northeast of the resource area. Hole ZKT4710 intersected 83 g/t Ag, 10.46% Pb, 0.46% Zn and 0.75% Cu over a 6.26 m interval. These intercepts have extended the boundary of the resource area approximately 300 m to the northeast.
Drill cores are NQ size. Drill core samples, limited by apparent mineralization contacts or shear/alteration contacts, were split into halves by sawing. The half cores are stored in the Company's core shacks for future reference and checks, and the other half core samples are shipped in securely sealed bags to the Chengde Huakan 514 Geology and Minerals Test and Research Institute in Chengde, Hebei Province, China, 226 km northeast of Beijing, the Zhengzhou Nonferrous Exploration Institute Lab in Zhengzhou, Henan Province, China, and SGS in Tianjin, China. All three labs are ISO9000 certified analytical labs. For analysis, the sample is dried and crushed to minus 1 mm and then split into a 200-300 g subsample which is further pulverized to minus 200 mesh. Two subsamples are prepared from the pulverized sample. One is digested with aqua regia for gold analysis with atomic absorption spectroscopy (“AAS”), and the other is digested by two-acid digestion for analysis of silver, lead, zinc, and copper with AAS.
Channel samples are collected along sample lines perpendicular to the mineralized vein structure in exploration tunnels. Spacing between sampling lines is typically 5 m along strike. Both the mineralized vein and the altered wall rocks are cut by continuous chisel chipping. Sample length ranges from 0.2 m to more than 1 m, depending on the width of the mineralized vein and the mineralization type. Channel samples are prepared and assayed with AAS at Silvercorp’s mine laboratory (“Ying Lab”) located at the mill complex in Luoning County, Henan Province, China. The Ying lab is officially accredited by the Quality and Technology Monitoring Bureau of Henan Province and is qualified to provide analytical services. The channel samples are dried, crushed and pulverized. A 200 g sample of minus 160 mesh is prepared for assay. A duplicate sample of minus 1 mm is made and kept in the laboratory archives. Gold is analysed by fire assay with AAS finish, while silver, lead, zinc, and copper are assayed by two-acid digestion with AAS finish.
A routine quality assurance/quality control (“QA/QC”) procedure is adopted to monitor the analytical quality at each lab. Certified reference materials (CRMs), pulp duplicates and blanks are inserted into each batch of lab 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 CRMs, field duplicates and blanks to each batch of 30 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 approximately 3-5% of the pulp samples to higher level labs to check for lab bias. Data from both the Company's and the labs' QA/QC programs are reviewed on a timely basis by project geologists.
Guoliang Ma, P. Geo., Manager of Exploration and Resource of the Company, is the Qualified Person for Silvercorp under NI 43-101 and has reviewed and given consent to the technical information contained in this news release.