Overview

Mine Type	Underground
Status	Care and Maintenance
Commodities	Silver Gold Lead Zinc
Mining Method	Shrinkage stoping Longhole stoping
Production Start	...
Snapshot	The Rosario Project was placed on care and maintenance in August 2021. This decision was made following an extensive review by management of the Rosario Mine operations and strategic options available including the potential sale of the operation. Certain assets related to the Rosario Project were sold in December 2021 as part of a tax restructuring of Impulsora Minera Santacruz, S.A. de C.V.

Deposit type

• Vein / narrow vein
• Mesothermal

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.

Mining Methods

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Comminution

Crushers and Mills

Processing

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Production

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

Operational metrics

Metrics	2021	2020	2019	2018	2017	2016	2015
Tonnes milled	....	....	76,088 t	61,184 t	78,963 t	91,852 t	79,249 t
Daily milling rate	....	....
Daily milling capacity	....	....	500 t

Personnel

Job Title	Name	Phone	Ref. Date
.......................	.......................	...........	Aug 10, 2023