Operations
TLP Mine (Ying Mining District)
Introduction
TLP
- Silver-lead mine ~11 km east-southeast of SGX
- Operates under the Tieluping-Longmen Mining License
- Owned 77.5% by Silvercorp
- Second-largest underground operation at Ying
- Property acquired in December 2007 and production resumed in March 2008
MINING
| Mine Type | Ramp supported underground |
| Mining Method | Re-suing and shrinkage |
| Reserve tonnage 1 | 2,580 kt |
| Reserve grades 1 |
213 g/t silver 3.05% lead |
| % of Ying’s LOM ore production | 21% |
| Primary metal | Silver |
| By-product metals | Lead |
1 Mineral reserves estimate as of December 31, 2021.
Exploration and Geology
Recent Work/ Highlights
Silvercorp completed 43,573 m of drilling in 276 diamond drill holes at TLP from June 1 to December 31, 2021.
High-grade silver-lead-zinc intercepts at the TLP mine:
- Underground hole ZKG0712 intersected a 1.36 m interval (1.03 m true width) of vein T11 grading 2,042 g/t silver, 36.86% lead, 6.73% zinc, 0.43 g/t gold, and 0.83% copper from 211.32 m depth, at an elevation of 632 m.
- Underground hole ZKG4T1601 intersected a 4.03 m interval (2.27 m true width) of vein T16 grading 1,003 g/t silver, 8.93% lead, 0.83% zinc, 0.16 g/t gold, and 0.10% copper from 79.56 m depth, at an elevation of 762 m.
- Surface hole ZKTDB2001 intersected a 0.87 m interval (0.82 m true width) of vein T3 grading 2,871 g/t silver, 2.47% lead, 0.79% zinc, 0.05 g/t gold, and 1.63% copper from 157.40 m depth, at an elevation of 1,027 m.
- Surface hole ZKTDB0608 intersected a 3.38 m interval (1.42 m true width) of vein T2W2 grading 1,052 g/t silver, 4.38% lead, 0.14% zinc, 0.05 g/t gold, and 0.10% copper from 164.11 m depth, at an elevation of 1,075 m.
High-grade intercepts of unexpected gold and gold-silver-lead-zinc veins within the resource area:
- Surface hole ZKTDB3504 intersected a 1.46 m interval (unknown true width) of an unknown gold vein grading 8 g/t silver, 0.02% lead, 0.02% zinc, 13.96 g/t gold, and 0.01% copper from 91.12 m depth, at an elevation of 909 m.
- Underground hole ZKT0016 intersected a 1.01 m interval (0.79 m true width) of gold vein T1W grading 12 g/t silver, 0.12% lead, 0.02% zinc, 13.91 g/t gold, and 0.01% copper from 95.26 m depth, at an elevation of 861 m.
- Underground hole ZKT1124 intersected a 2.04 m interval (1.70 m true width) of vein T2 grading 281 g/t silver, 3.32% lead, 0.52% zinc, 6.83 g/t gold, and 0.59% copper from 56.78 m depth, at an elevation of 749 m.
High-grade silver-lead-zinc intercepts within the resource area (northwest side):
- Hole ZKT0427 intersected a 0.59 m interval (0.51 m true width) of vein T33 grading 0.13 g/t gold, 1,794 g/t silver, 0.19% lead, 0.06% zinc, and 0.28% copper from 141.82 m depth, at an elevation of 916 m.
- Hole ZKTDB1512 intersected a 1.54 m interval (0.48 m true width) of vein T33W3 grading 0.05 g/t gold, 338 g/t silver, 0.39% lead, 0.15% zinc, and 0.03% copper from 204.80 m depth, at an elevation of 990 m.
Geological Background
The TLP, LME and LMW mines have similar styles of mineralization. Mineralization at TLP is currently defined in 78 veins. The five largest veins, T3, T2, T3E, T1, and T11, contain 35% of TLP’s current mineral resources. Sampling in workings along or across these veins indicates that a significant amount of the vein material is mineralized with massive, semi-massive and disseminated galena as well as minor amount of chalcopyrite and sphalerite. Vein widths range from 0.3 m to over 10 m. Other metallic minerals present in much smaller amounts include pyrite, hematite, and very sparse amounts of acanthite.
The veins at TLP mostly dip westward while those at LM dip steeply both east and west. Previous mining and stoping along TLP’s T1 and T2 vein structures indicate that the mineralization plunges shallowly to the north within structural zones extending hundreds of metres to a thousand metres or more along strike. The mineralization occurs as massive accumulations or disseminations in the veins. The galena often occurs as massive tabular lenses comprised of coarsely crystalline aggregates or fine-grained granular “steel galena” bodies, which can be up to 1.0 m thick and over 100 m along vertical and horizontal dimensions.
Most of the silver in the TLP-LM veins is present as microscopic inclusions in the galena. It appears that Ag:Pb ratios are distinctly different between veins of the northern TLP area (North Zone) and the southern TLP and LM area (South Zone). Based upon 15 verification samples collected for a previous Technical Report (Broili et al. 2008), veins in the South Zone appear to have much higher zinc contents and higher Ag:Pb ratios (90 to 130 grams silver for each percent lead) than veins from the North Zone (5 to 15 grams silver for each percent lead), as well as proportionally less gold. This difference could be the result of zonation or reflects differences in the level of exposure.
The veins occur in relatively permeable fault-fissure zones and are extensively oxidized from the surface to depths of about 80 m. Within this zone, the veins show many open spaces with conspicuous box-work lattice textures resulting from the leaching and oxidation of sulphide minerals. Secondary minerals present in varying amounts in this zone include cerussite, malachite and limonite. Beneath this oxide zone, sulphide minerals are mixed with secondary oxide minerals in the vein, with sulphides becoming increasingly abundant with depth until about 150 m, beyond which fresh sulphides are present with little or no oxidation.
Wall rock alteration consists of numerous quartz veinlets accompanied by sericite, chlorite, silicification, and ankerite on fractures. The vein systems appear to have better continuity and increasing mineralization with depth, and many veins exposed in the underground workings are often significantly richer in silver-lead-zinc than the same veins exposed at the surface. This could be due to either leaching from surface outcroppings or—the more likely explanation—to primary mineral zoning. The TLP system also contains some epithermal veins and veinlets. These veins contain abundant large vugs lined with carbonate and they either crosscut or follow some of the mesothermal filled structures.
