KEY MEXICAN SILVER DEPOSITS OF THE SIERRA MADRE
THE ZACATECAS SILVER MINING DISTRICT
Most epithermal deposits in Mexico associated with Tertiary volcanism associated with the evolution of the Sierra Madre and
Guerrero Terranes.
The regional distribution of deposits is closely associated in space with regional-scale faults.
In the Zacatecas region the San Luis-Tepehuanes Fault and associated splays exert a fundamental control on mineralization.
A westward flexure of the fault in the Zacatecas region is important with respect to structural localization and control of major deposits. Zacatecas Silver Corp. concessions are ideally located with respect regional structures.
Epithermal deposits of the Zacatecas region were historically modelled as low sulphidation type with restricted vertical precious metal interval.
Re-modelling suggests deep boiling intermediate sulphidation types are also present — allowing for much deeper resource potential.
Understanding the vertical location in the system and type of system — allows for much more effective drill targeting.
Historical resource of 19.47 Moz Ag eq. at 100 g/t Ag eq. cut-off) from 3.95 Mt at 153 g/t Ag eq. Mineralization open along strike and at depth.
Three silver-gold-base metal mineralized veins over a strike length of at least 3 km.
Large number of silver-base metal mineralized veins associated with a sigmoidal dilational zone that is 3 km in strike length and up to 600 m wide. Represents the NW strike extension of the Veta Grande vein system with reported historical production of >200 Moz Ag.
Relatively unexplored target numerous silver-base metal mineralized veins and a gold-anomalous 800 m long hematitic breccia that is up to 40 m wide.
San Gill: Historical working at San Gill associated with an area of clay alteration (where hot fluids have caused minerals in the host rock to change to clays). This is an important vector in hydrothermal systems. Cozamin workings and plant in the background.
El Cristo: Historical workings define vein locations. Zacatecas Silver Corp is currently re-mapping this extensive vein system — which represents the NW extension of the original Veta Grande Mine.
Exploration and permitting work commenced in Qtr 4 of 2020. In addition to resource remodelling work – milestones include:
- Remapping of the Panuco, El Cristo and San Manuale/San Gill vein systems which has confirmed extensive intermediate sulphidation veins systems.
- Structural remodelling of vein systems and 3D mopdelling to allow targeting of highest value drill targets.
- Submission of a 100 kg bulk sample of mineralization used in the historic Panuco inferred resource estimate. This benchscale testing indicated that robust gold, silver, lead and zinc recoveries above 90% are achievable.
- Drill permits awarded for Panuco and San Gill by SEMARNAT and 2 to 5 year land access agreements in place at both prospects with the Municipality, Ejido’s and private landowners.
- Environmental studied completed at El Cristo and San Manuel and drill permit applications submitted.
*Historical Resource Estimate prepared by Phu Bui, P. Geo and Michael O’Brian, P.Geo on August 20, 2019.
THE PANUCO DEPOSIT
75 holes (23,444 m) drilled by a previous operator. Intercepts included:
- Hole PA09-01: 174-176 m for 1.79 m grading 0.32 g/t Au, 517 g/t Ag, 0.43% Pb and 2.32% Zn.
- Hole PA11-68: 625-626.5 m for 1.5 m grading 1.05 g/t Au, 668 g/t Ag, 0.01% Pb and 0.01% Zn.
Mineralization is open at depth and along strike with drill ready targets.
A number of undrilled sections of veins, fault splays and jogs where vein orientation changes, are important exploration targets. The potential NW extension of veins beneath shallow cover requires further work.
EL CRISTO VEIN SYSTEM
Multiple silver-base metal veins representing the NW strike extension of the Veta Grande vein system — the latter with reported historical production of >200 Moz Ag.
Brecciated and crustiform-collaform banded veins of between 0.1 -7.0 m in thickness are hosted in a sigmoidal dilational zone that is over 2.5 km long and up to 600 m wide.
Dilational zones result in open fractures during faulting — important for inflow of mineralizing fluids and creating space for metal and gangue deposition.
Only 8 historical holes drilled. A very robust exploration target.
THE MULEROS VEIN SYSTEM
37 holes (6704 m) drilled by a previous operator. Veins relatively Au-rich. Intercepts included:
Hole MU07-07: 73.95 – 76.25 m for 2.30 m grading 1.56 g/t Au and 286 g/t Ag.
Hole MU08-36: 261.1 – m for 1.5 m grading 1.05 g/t Au, 668 g/t Ag, 0.01% Pb and 0.01% Zn.
Although a few deep holes were drilled — overall the historic drill program was designed to test the upper 100 m of the vein. The depth potential is untested.
Fault splays at the NW end of the North Vein, El Rosario Vein and historical shafts in the southwest are robust targets . The potential NW extension of veins beneath shallow cover requires further work.
THE SAN MANUEL – SAN GILL VEIN SYSTEM
Multiple quartz-sulphide Ag-base metal veins with strike lengths of between 400 – 1400 m. Largely unexplored and only nine historical drill holes.
Large areas of shallow recent cover (soils, sand and gravel) potentially cover vein extensions.
800 m long by up top 40 m wide NS trending hematitic breccia. Highly significant. Gold deposit in the area preferentially developed on N-S trends. Several historical drill hole intercepts confirm presence of elevated gold geochemistry.
Hole MG11-08: 4.16 m grading 1.14 g/t Au, 128 g/t Ag, 2.23% Pb and 1.86 % Zn.
The Company has collected over 100 kg of mineralization from intervals used in the Panuco inferred resource estimate and shipped it to SGS Lakefield for bench-scale metallurgical test-work. The program is designed test process flow-paths to further optimize silver, gold, lead and zinc recoveries.