Name of the Mine
Santa Elena mine.

Location  
Sonora, Mexico, about 150 km north-east of the state capital city of Hermosillo and 7 km east of the community of Banámichi.

Mine Owner/s  
First Majestic Silver Corp.

Brief Description  
The Santa Elena mine is an underground gold- and silver-producing mining complex, owned and operated by First Majestic Silver Corp’s wholly owned indirect subsidiary Nusantara de México.

Brief History  
London-based Consolidated Goldfields of Mexico owned and operated the mine in the late nineteenth century and mined from surface and underground until about 1910. First Majestic notes that there is no indication of any further significant mining or exploration at the mine until Industrias Peñoles SA de CV drilled several holes on the property in the 1960s. 

During the early 1980s, Tungsteno de Baviacora owned the property and remained under control of the company until 2009, when SilverCrest Mines Inc. acquired 100% of the Santa Elena property. 

SilverCrest started production from the Santa Elena openpit in October 2010.

First Majestic acquired the Santa Elena property in October 2015. 

Primary Metals/Minerals  
Silver and gold.

Secondary Metals/Minerals  
Not disclosed.

Geology/Mineralisation  
The Santa Elena deposits are hosted in rocks of the Sierra Madre Occidental (SMO), an igneous province that extends from the US/Mexican border south to Guadalajara, Mexico. The SMO geological province comprises late Cretaceous to early Miocene volcanic and sedimentary rocks that formed during two main periods of continental magmatic activity. 

The first period, concurrent with the Laramide orogeny, produced an intermediate intrusive suite and its volcanic counterpart. These rocks, referred to as the Lower Volcanic Complex (LVC), include the Late Cretaceous to Paleocene volcanic succession of the Tarahumara Formation and are intruded by the Sonora batholiths. In the late Eocene, volcanism became dominated by rhyolitic ignimbrites. Extensional basins and associated continental sedimentary deposits formed between 27 mega-annum (Ma) and 15 Ma in a north-north-west-trending belt along the western half of the SMO.

Many significant porphyry deposits of the SMO occur in the LVC rocks. North-west-trending fault zones associated with early Eocene east–west directed extension appear to control epithermal mineralisation in the Sonora region. 

The Santa Elena main vein and the Ermitaño vein have orientations similar to this extensional trend. The Santa Elena and the Ermitaño deposits are the most significant zones of gold and silver mineralisation currently known within the Santa Elena property.

Reserves  
As at December 31, 2023, Santa Elena hosted proven underground reserves (sulphides) of 140 000 t grading 140 g/t silver and 1.54 g/t gold. Total probable reserves were estimated at 679 000 t grading 167 g/t silver and 1.3 g/t gold.

Resources  
Total measured and indicated resources as at December 31, 2023, were estimated at 5.03-million tonnes grading 101 g/t silver and 2.69 g/t gold. Inferred mineral resources were estimated at 3.34-million tonnes grading at 95 g/t silver and 2.01 g/t gold.

Type of Mine
Underground.

Mining Method  
Sublevel longhole stoping, longhole Avoca and cut-and-fill. The method assigned to a vein depends on the vein characteristics and rock mass characteristics, for example width, dip and rock competence. 

Major Infrastructure/Equipment  
Most of Santa Elena’s support facilities are located within a 1.5 km radius, facilitating the transportation and logistics of personnel, material and equipment. 

The main infrastructure consists of roads; crushing, grinding and processing facilities; a previously processed leach pad; a waste storage facility; a filtered-tailings storage facility; administrative offices; a first-aid station; a warehouse; an assay laboratory; a liquefied natural gas power generation plant; diesel gensets for backup; a maintenance shop; water storage tanks; and a water supply tank. 

Prospects  
In July 2024, First Majestic announced the discovery of a significant new, vein-hosted gold and silver mineralised system at Santa Elena. This new high-grade discovery, the Navidad vein system, was made at depth adjacent to the company’s 100%-owned and currently producing Ermitaño mine.

The full extent and geometry of the Navidad gold and silver vein system are not yet known, and the exploration potential is open in all directions. 

Contact Details 
First Majestic Silver Corp
Tel +1 604 688 3033
Email info@firstmajestic.com
Website https://www.firstmajestic.com/