Silvercorp Metals Inc. is pleased to report results from its exploration program at the LME mine, Ying Mining District, Henan Province, China. Extensive exploration drilling and tunneling are ongoing at the LME mine, and all other mines at the Ying Mining District.
The exploration program from October 1, 2019 to September 30, 2020 at the LME mine has targeted the down dip and along-strike extensions of known mineralized vein structures in the production areas. So far, 13,515 metres (“m”) from a total of 53 diamond drill holes, including 47 underground holes and six surface holes, have been completed. Assay results for 32 holes have been received with 21 holes intercepting mineralization.
Most of the infill underground drills were focused on high grade drill intercepts from previous drill programs where mining access tunnels were developed but the mineralization was not mined. This drilling program intersected many higher grade silver-lead ore zones, including veins LM5, LM5E, LM5E1, LM5E2, LM5W, and LM6. Some new vein structures, including LM2E, LM5Ea and LM5Ea1, were discovered in this production area. Most of the higher grade silver-lead zones can be mined using existing access and development tunnels, which is expected to substantially reduce tunnel development costs at the LME mine going forward. Eight rigs have been drilling at the LME mine since July 2020 to continue identifying these types of easily accessible zones.
Low Angle Gold Structures
The step-out drilling also targeted the LM4E2 structure which is dipping at a 10-35 degree angle, along a northeast strike of 60 degrees. The LM4E2 vein contains gold mineralization characterized by quartz-pyrite banding and K-feldspar-silicification alteration. Sporadic drill intercepts from over 20 holes have defined a mineralized area of >1,500m in length and >800m down dip. Holes ZKLDB2101, ZKL6713, ZKL58T1703 and ZKL5305_1 intersected intervals of 3.31m, 4.21m, 0.99m, and 1.10m of vein – LM4E2 with gold grades of 4.57 g/t, 4.53 g/t, 4.94 g/t and 3.31 g/t, respectively. Locally, LM4E2 is over-printed by late stage sub-vertical silver-lead veins such as LM5 and LM6, as a result, hole ZKL53S04_1 intercepted 6.08m of LM4E2 grading 375 g/t Ag and 1.61% lead, with only 0.09 g/t Au. Further drilling is ongoing to test the continuity of vein LM4E2.
Hole ZKL6713 discovered another low angle dipping gold structure – LM66W. It returned a 4.51m intercept (3.11m true thickness) grading 4.53 g/t Au without other metals present. LM66W is believed to be another low angle dipping gold structure located approximately 100m below the LM4E2 structure.
Additionally, the Company continues to test for new vein structures in previously less explored areas. The step-out drilling in the southeast part of the LME mine discovered new veins, including LM61, LM62, LM66, LM66E, and LM66E3.
Drill cores are NQ size. Drill core samples, limited by apparent mineralization contacts or shear/alteration contacts, were split into halves by saw cutting. 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, 226km northeast of Beijing, the Zhengzhou Nonferrous Exploration Institute Lab in Zhengzhou, Henan Province, China, and SGS-CSTC Standards Technical Services (Tianjin) Co., Ltd., Tianjin, China. All the three labs are ISO9000 certified analytical labs. For analysis, the sample is dried and crushed to minus 1mm and then split to a 200-300g 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 with two-acids 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 5m along strike. Both the mineralized vein and the altered wall rocks are cut by continuous chisel chipping. Sample length ranges from 0.2m to more than 1.0m, 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 200g sample of minus 160 mesh is prepared for assay. A duplicate sample of minus 1mm is made and kept in the laboratory archives. Gold is analysed by fire assay with AAS finish, and 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 CRM, 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.
Silvercorp is a profitable Canadian mining company producing silver, lead and zinc metals in concentrates from mines in China. The Company’s goal is to continuously create healthy returns to shareholders through efficient management, organic growth and the acquisition of profitable projects. Silvercorp balances profitability, social and environmental relationships, employees’ wellbeing, and sustainable development. For more information, please visit our website at www.silvercorp.ca.
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