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.