42-7 Mineralogy and fluid nature of the Antares Sur ore body, Velardeña Mining District, Durango (Mexico).

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

Presenting Author:

Authors:

Abstract:

The Velardeña mining district, Durango, is located at the westernmost termination of the Parras Transversal Sector within the Mexican Orogen. The ore deposits are hosted in a succession of Mesozoic carbonate rocks intruded by Oligocene felsic to intermediate igneous bodies related to the Sierra Madre Occidental. Antares Sur is one of the main mineralized bodies of the district and, although it has been economically exploited, further insight into its genetic–evolutionary development is key to understanding its relationship with the other mineralized bodies in the district. Using petrographic and fluid inclusion studies, this work aims to describe the mineralogy of Antares Sur and the nature of its mineralizing fluids.

The results show a predominance of pyrrhotite, arsenopyrite, chalcopyrite, sphalerite, and marcasite, hosted in fluorite and calcite, with the presence of actinolite. The samples indicate that the highest concentration of mineralization occurs at the contact with the rhyolitic intrusive body, whereas within the skarn the mineralization is more disseminated. Microthermometric results indicate fluids with temperatures ranging from 450° to 530 °C and salinities of 31.3 to 32.6 wt. % NaCl during the mineralizing stage, suggesting the influence of magmatic-derived hydrothermal fluids. Overall, these observations indicate that mineralization at Antares Sur developed under classical polymetallic skarn conditions related to rhyolitic intrusions. This study contributes to a better understanding of the evolution of the Antares Sur body and its relationship with the Velardeña mining district.

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

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