36-5 Geological and Structural Characteristics at the Intersection of the Veta Madre and Aldana Faults (El Orito zone), Guanajuato Mining District, Mexico.

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

Poster Booth No.: 23

Presenting Author:

Juan García-Colín Edgar Angeles-Moreno Alejandra Menéndez-González Ángel Méndez-López Beatriz Beltrán-MartínezIsidro Loza-Aguirre Raúl Miranda-Avilés

Authors:

García-Colín , Juan Carlos¹, Angeles-Moreno , Edgar², Menéndez-González , Alejandra³, Méndez-López , Ángel Antonio⁴, Beltrán-Martínez, Beatriz Coral⁵, Loza-Aguirre , Isidro⁶, Miranda-Avilés , Raúl⁷

(1) División de Ingenierías, Universidad de Guanajuato, Guanajuato, Guanajuato, Mexico, (2) División de Ingenierías, Universidad de Guanajuato, Guanajuato, Guanajuato, Mexico, (3) División de Ingenierías, Universidad de Guanajuato, Guanajuato, Guanajuato, Mexico, (4) División de Ingenierías, Universidad de Guanajuato, Guanajuato, Guanajuato, Mexico, (5) Empresa Geo and Petroservices, Guanajuato, Guanajuato, Mexico, (6) División de Ingenierías, Universidad de Guanajuato, Guanajuato, Guanajuato, Mexico, (7) División de Ingenierías, Universidad de Guanajuato, Guanajuato, Guanajuato, Mexico,

Abstract:

El Orito zone in the city of Guanajuato is located at the confluence of the two major faults of the Guanajuato Mining District (GMD): the Aldana Fault (NE-SW) and the Veta Madre Fault (NW-SE). Both structures hosted intermediate to low sulfidation epithermal mineralization. The Veta Madre Vein, approximately 16 km long, has historically been part of the mining activity of the Guanajuato Mining District (GMD), with a great amount of silver production. Within this area (El Orito) lies one of the most important mineral orebodies of the Veta Madre system, the Valenciana Mine. Other epithermal veins are in hanging wall of Vetra Madre Fault as San Prospero Vein and Nopal Systems Veins. This work presents a geological-structural map of the El Orito area and geometric and kinematic analysis of faults, fractures, and mineral veins. Progress of these results is presented. Some results show the presence of structural contacts between the Mesozoic rocks and the Guanajuato Conglomerate Formation (GCF). The GCF is composed of a sequence of sedimentary breccias, conglomerates, sandstones, andesitic flows, peperites, and volcanic breccias. Structurally, the Aldana fault and the Veta Madre fault exhibited a complex interaction, which is reflected in their structural kinematics. The Eocene Rocks (GCF) experienced at least several faulting events with lateral, oblique, and extensional kinematics. Some of these faulting events were associated with mineralization, sedimentation, and volcanism. The interaction of the Aldana Fault (NE-SW) and La Veta Madre (NW-SE) exerted structural control on the epithermal veins of the El Orito zone, permeability of hydrothermal alteration zones, and other geological features. The structural interaction between NE-SW and NW-SE structures is relevant in the Guanajuato Mining District for understanding the economic distribution of Au-Ag mineralization and mining exploration.

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

© Copyright 2026 The Geological Society of America (GSA), all rights reserved.