36-3 Geological-Structural characterization of “Mexican-type Sn Veins” in the Sierra Norte of Guanajuato: Mining opportunity areas for Ce, In, Nb, Tl ore deposits.

Session: Cordilleran Mineral Systems: Interdisciplinary Perspectives on Critical Metal Ore Deposits (Posters)

Poster Booth No.: 21

Presenting Author:

Luis Beristain Beristain

Authors:

Beristain Beristain, Luis Alberto¹, Rodríguez Díaz, Augusto Antonio ², Ramos Arias, Mario Alfredo³, Pi Puig, Teresa ⁴, Casas García, Raymundo ⁵, Vallejo Herrera , Brian Fernando ⁶, Vera Herrera, Moises ⁷

(1) Ingenieria Geológica, Instituto Politécnico Nacional Escuela Superior de Ingenieria y Arquitectura Unidad Ticoman, Ciudad de Mexico, Mexico, (2) Departamento de Recursos Naturales, Instituto de Geofísica Universidad Nacional Autónoma de Mexico, Ciudad de Mexico, Mexico, (3) Instituto Politécnico Nacional, Ciudad de Mexico, Mexico, (4) Departamento de Procesos Litosféricos, Instituto de Geología Universidad Nacional Autónoma de México, Ciudad de Mexico, Mexico, (5) TU Bergakademie Freiberg, Freiberg, Germany, (6) Instituto de Geofísica Universidad Nacional Autónoma de Mexico, Ciudad de Mexico, Mexico, (7) Instituto Politécnico Nacional Escuela Superior de Ingenieria y Arquitectura, Ciudad de Mexico, Mexico,

Abstract:

Tin mining of Sn currently plays an essential role for the metallurgical and electronics industries. However, in Mexico, there is no in-depth research referring to the characteristics of the deposits, ore minerals, by-products, genesis, and deposit typology. National Sn production is restricted to the central and northwestern parts of the territory, on a small-scale mining level.

The San Felipe mining region in Guanajuato is distinguished by its abundance of vein-type deposits of cassiterite and quartz. This study consists of the geological and mineralogical characterization of the El Perdido y Huilancha mineralized zones, located in the northern part of this region; highlighting their mining-geological relevance and evidencing exploration guides.

The analysis involved field geology and petrography, short-wave infrared spectroscopy (SWIR), electron microscopy, EDS mineral chemistry analysis, and elemental mapping. The Sn deposits are hosted in Oligocene topaz-bearing rhyolites belonging to the Sierra de San Miguelito volcanic complex, structurally controlled by normal faults of the Graben Villa de Reyes (GVR). The ore deposits are associated to vein structures with a NW-SE orientation, extending along the Hulancha I and II transtensive-type fault. The host rock in both mineralized bodies is a flow-banded rhyolite with occasional presence of topaz microcrystals from Cerro El Perdido dome. The host rock exhibits hydrothermal halos alteration, composed by: quartz, adularia, and hematite (potassic paragenesis) association, and smectite, manganese oxides, chalcedony, and opal (argillic paragenesis). The mineralization in the mineralized zones consists of cassiterite in colloform bands and botryoidal arrangements, specular and microgranular hematite, monazite filling open spaces and isolated microparticles. Cerium, Nb, and Tl in monazite, and In in cassiterite were found via bulk composition and elemental mapping analyses.

The structure, textures, and alteration mineral associations denote a magmatic-hydrothermal genetic character for the El Perdido y Huilancha mines, comparable to Mexican-type Sn deposits, with exploration guides: topaz-bearing rhyolites and NW-oriented transtensive structures within the GVR.

The by-products In, Ce, Nb, Tl open an opportunity in Sn mining to be considered for the mining as strategic elements, whose extraction is possible from analogous deposits in other parts of the world.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3, 2026

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