On December 18, 2023, Santacruz Silver Mining Ltd. sold its shares in Santacruz Holdings Ltd., which has 100% ownership in Impulsora Minera Santacruz, S.A. de C.V., a non-core Mexican subsidiary of the Company, to a private Mexican group.
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Summary:
The Veta Grande Vein System
The Veta Grande vein system has been estimated to be approximately 16 km long. Concessions owned and operated by Santacruz cover approximately three km of strike length at the northwest end of the vein system. The alteration consists of a 1-5 m narrow and vein-proximal zone of argillic alteration within weak to moderate and pervasive silicification peripheral to the vein structures. Pervasive oxidation of the vein structure exists at surface and continues to an average depth of approximately 30 m.
The Veta Grande vein is the principal vein structure within the Veta Grande vein system and is historically the most important vein of the Zacatecas Mining District. It varies from two to 30 m in width, averaging approximately 10 m wide. The vein strikes northwest-southeast and dips between 60-90o to the southwest. The vein consists of quartz, chalcedony and calcite and often exhibits colloform and crustiform textures with small to medium (1-5 mm) euhedral quartz crystals filling open space cavities. The dominant sulfide mineralization consists of pyrite, sphalerite, and galena, with rare chalcopyrite.
In the immediate vicinity of the Armados and Garcia portals are three known veins situated in the structural footwall of the Veta Grande vein. These veins are identified as Armados vein, San Jose vein, and La Flor vein. Each vein is compositionally and texturally similar to the Veta Grande vein. Vein thickness varies from <1 to >5 m and averages approximately 2-3 m wide and strikes northwestsoutheast and dips between 50-60o to the southwest. The San Jose vein contain narrow zones (5-10 cm) of massive sulfide along vein margins while the La Flor vein contains brecciated textures with small to medium (1-20 cm) angular clasts of argillic altered andesite that frequently occur within a sulfide-quartz matrix. The veins have been previously exploited from underground and are currently being explored and mined by Santacruz.
La Cantera Vein System
The La Cantera vein system is characterized by the La Cantera principal vein and subordinate veins in the footwall of the structure. The vein system is situated at the northern limits of Zacatecas city and approximately 10-12 km south of the Veta Grande vein system. It is one of the southernmost Ag-Pb-Zn rich vein systems in the Zacatecas Mining District. The La Cantera vein is approximately <1 m to >20 m wide, with an average vein width of approximately 10 m. It strikes northwest-southeast and dips between 60-90o to the southwest. The La Cantera vein occupies a structural contact between andesitic volcanic rocks situated in the structural footwall of the vein and andesitic volcanic rocks and Red Conglomerate in the structural hanging wall of the vein. Late post-vein and post-mineral cross-faults cut the vein structure at various angles with minor displacement.
The vein is dominantly quartz in composition with colloform, crustiform and breccia vein textures. The breccia textures consists of 1-10 cm angular fragments of weakly to moderately altered andesite volcanic rocks supported in a quartz-sulfide matrix. Mineralization at the La Cantera vein consists of fine to medium grained (0.1-1 cm), disseminated to massive pyrite, sphalerite, and galena (rare chalcopyrite) with native silver, and argentite. The La Cantera vein has a higher sulfide content compared to the veins of the Veta Grande vein system and locally contains massive sulfide consisting of galena, sphalerite, and pyrite.
The La Cantera vein system exhibits the highest concentration of base metal sulfides on the project which may suggest a deeper level of emplacement at the La Cantera vein system with progressively shallower levels of emplacement to the north at the Veta Grande and Panuco vein systems.
Navidad Vein System
The Navidad vein system is comprised of the Navidad principal vein and subordinate veins in the footwall of the principal vein. Vein composition and alteration is similar to the La Cantera vein. The vein is approximately 10 m wide, strikes south-southeast and dips 60-90o to the southwest.
Muleros, El Cristo and San Manuel-SanGil Exploration Areas
The Muleros Target covers an area of approximately 408 Ha and is centered at coordinates 747,965 mE and 2,532,432 mN on concession title 224363 (Macario II). The center of the target area is located 3.8 km northeast of Morelos township and 6.1 km northwest of Vetagrande township. Four sub-parallel quartzcalcite veins striking 120°-130° outcrop along a two km strike length. Veins generally dip 75° to the southwest with local dips between 50°-85° to the southwest. Mineralization is primarily hosted in vein breccia averaging 1.0 m in true thickness, ranging from <1 m and up to 5 m in true thickness. Mineralization consists of argentite, pyrite, galena and sphalerite. Disseminated mineralization as quartzpyrite zones occurring between veins have also been identified.
The El Cristo target covers an area of approximately 316 Ha and is centered at coordinates 748,266 mE and 2,529,455 mN on concession title 211822 (Morelos). The center of the target area is located between Muleros township and Vetagrande township. The El Cristo target is comprised of five to eight irregular to sub-parallel quartz-calcite veins striking 300°-310° azimuth along a 1.8 km strike length. The Papalote vein is identified as the main vein structure in the system. Veins are directly on trend with the Veta Grande vein system and they are interpreted to be the northwestern extension of Veta Grande. The vein structures are irregular and have dips ranging between 30° to 70° to the northeast and to the southwest. The structures occur as banded quartz-carbonate veins and breccia veins <0.2 m to 1.8 m wide. Mineralization is confined to the veins and consists of argentite, galena, sphalerite and minor chalcopyrite.
The San Manuel-San Gil target covers an area of approximately 828 Ha, and is centered at coordinates 748,044 mE and 2,526,254 mN on concession title 217430 (San Gil). The target hosts a series of east and northwest trending quartz-carbonate veins that dip to the north and south, with thicknesses varying from 0.1 m to 7.0 m, and lengths ranging from 400 to 1,400 m over a 2,000 m trend. Vein widths average approximately one meter. Mineralization and vein styles are similar to the El Cristo target.
Panuco Vein System
The Panuco deposit area consists of three packages of interbedded and intercalated rocks belonging to the Chilitos Formation. These units are subsequently cut by younger diorite to quartz-diorite dykes.
The first package consists of mafic to intermediate coherent volcanic units: including fine grained to feldspar porphyritic and pervasively chloritic andesites and basalts. The second package consists of andesite tuffs and epiclastic units: including fine grained and foliated andesite ash tuff, brecciated lithic tuff with sandstones and shale clasts, and fine to medium grained reworked tuffs that are commonly described as volcanic shales and volcanic sandstones. The third package consists of epiclastic and clastic units: including limestone, calcareous shales, greywacke, arenite and conglomerates.
The Panuco deposit is defined by three prominent northwest-southeast trending and southwest dipping vein structures that have resulted from brittle fracturing. These vein structures are identified as the Panuco NW, Panuco Central and Tres Cruces. Displacement along and between these vein structures is currently unknown and presumed to be minor. Within the 1,000 m orthogonal distance between the Panuco NW vein and Tres Cruces, subordinate veins have been identified in sub-parallel orientation, particularly within the structural hanging wall of each vein.