On November 30, 2023, the Santacruz Silver Mining Ltd. completed the sale of its 100% interest in Santacruz Holdings(“SCH”), a Canadian holding company which had 100% ownership in Impulsora Minera Santacruz, S.A. de C.V. (“IMSC”), to a private Mexican group. IMSC held the Rosario Project that was placed on care and maintenance in 2021, and had net liabilities of $14,706 as at the date of the sale.
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Summary:
Mineralization is hosted in two veins with a general strike of N60W, dipping between 45 to 60 degrees southwest. The host rock of the veins is comprised of the Zacatecas formation, a mid to late Triassic turbidite sequence, consisting of beds of dark grey, green and grayish-green shale, sandstone, conglomerate and siltstone. The veins extend over a length of 2.5 to 3.0 kilometers, and to a depth of at least 150 to 200 meters, as determined from available drilling data (Rodriguez et al., 1987). Each of the Rosario I and Rosario II veins vary in width from 0.4 to 2.5 meters. Mineralization appears to have occurred in three stages, with the third stage precipitating the silver bearing minerals. This deposit has been described as a mesothermal vein system based on temperature (195 to 338°C), although mineralization is typical of other deposits in Mexico which are described as epithermal. Abundant sulfides, sphalerite pyrite and galena with subordinate amounts of chalcopyrite, arsenopyrite and hematite, can be found within the veins. Additional minerals identified through electron microscopy include freibergite, tetrahedrite, boulangerite, pyrargyrite, argentite, stromeyerite, and diaphorite (Rodriguez et al., 1987).
The Rosario Veins at the Rosario Project are vein filled faults defined as mesothermal within epithermal limits.
Based on fluid inclusion work in quartz and calcite, Palacios and Arriaga (1994) postulated that the mineralization in the Rosario veins occurred in three stages, the most important of which was the latest stage in which argentiferous minerals were deposited. The temperatures during deposit formation were determined using fluid inclusions in quartz and calcite. The third stage occurred within epithermal temperature ranges between 195 to 262 degrees Celsius with salinity of 12% to 16%. Palacios and Arriaga state that fluid inclusion temperatures indicate that this is a mesothermal type deposit based on temperatures defined by Lindgren (1933) although based on the presence of adularia and silver sulfosalts, the Rosario veins more closely resemble an epithermal deposit.
Production
In October 2021, Santacruz Silver Mining ceased operations at the Rosario Mine and placed it on care and maintenance.
| Commodity | Units | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|
Silver
|
oz
| .... | .... | 149,687 | 74,981 | 112,663 | 425,838 | 471,893 |
|
Gold
|
oz
| .... | .... | 508 | 412 | 1,007 | 496 | 336 |
|
Lead
|
t
| .... | .... | 287 | 136 | 157 | 705 | 781 |
|
Zinc
|
t
| .... | .... | 1,350 | 1,081 | 1,488 | 2,635 | 1,896 |
|
Silver Equivalent
|
oz
| .... | .... | 465,576 | 304,461 | 442,329 | 828,094 | 832,283 |
All production numbers are expressed as metal in concentrate.