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Geochemical constraints on the genesis of the ‘Montaña de Manganeso’ vein-type Mn deposit, Mexican Plateau

Author: Madondo, J.; Canet, C.; González-Partida, E.; Rodríguez-Díaz, A.; Núñez-Useche, F.; Alfonso, P.; Rajabi, A.; Pi, T.; Blignaut, L.; Vafeas, N.

Type of activity: Journal article
Journal: Ore geology reviews
Date of publication: 2020-10-01
Volume: 125
First page: 103680: 1
Last page: 103680: 16
DOI: 10.1016/j.oregeorev.2020.103680

Repository: http://hdl.handle.net/2117/331273
URL: https://www.sciencedirect.com/science/article/pii/S0169136819309977
Abstract: Manganese mineralization at Montaña de Manganeso, San Luis Potosí state, consists of oxide ores that form sharp contacts with volcanic host rocks. The orebodies are generally in the form of veins and irregular masses, and locally as mineralized breccias. Petrographic analyses indicate that the mineralization is multi-episodic, with colloform and crustiform textures predominating. The X-ray diffraction and electron microscopy show that manganese oxides (todorokite, birnessite, pyrolusite, roman...

Manganese mineralization at Montaña de Manganeso, San Luis Potosí state, consists of oxide ores that form sharp contacts with volcanic host rocks. The orebodies are generally in the form of veins and irregular masses, and locally as mineralized breccias. Petrographic analyses indicate that the mineralization is multi-episodic, with colloform and crustiform textures predominating. The X-ray diffraction and electron microscopy show that manganese oxides (todorokite, birnessite, pyrolusite, romanechite and cryptomelane) are the main ore minerals, while iron oxides (goethite and hematite) are accessory. The most common gangue minerals are calcite and quartz with subordinate amounts of barite. According to fluid inclusion microthermometry, the mineralization is associated with aqueous solutions of intermediate salinity (8–16 wt% NaCl equivalent) and temperatures between 101 and 140 °C. Stable isotope analysis of calcite (d13CPDB: -7.76 to -6.32‰; d18OPDB: -8.01 to -4.71‰) and barite (d34S: 7.9–13.6‰) shows a contribution of magmatic volatiles to hydrothermal fluids dominated by meteoric water (calculated d18Ofluid: 6.58–13.14‰, relative to SMOW). Argillic alteration is the most widespread hydrothermal alteration at Montaña de Manganeso and indicates fluid temperature below ~150 °C and near neutral pH. Much more local, advanced argillic alteration, revealed by the occurrence of kaolinite, is interpreted as a steam-heated overprint, which in turn suggests a boiling process that must have happened at greater depths. The Mn ores formed through a process of mixing of: (a) boiled-off hydrothermal fluids, with (b) cold, diluted meteoric water. Our results support a hot-spring deposit model, according to which Montaña de Manganeso corresponds to the shallowest portion of an epithermal system formed in a continental volcanic arc setting. © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Citation: Madondo, J. [et al.]. Geochemical constraints on the genesis of the ‘Montaña de Manganeso' vein-type Mn deposit, Mexican Plateau. "Ore geology reviews", 1 Octubre 2020, vol. 125, p. 103680: 1-103680: 16.
Keywords: Epithermal, Fluid inclusions, Geochronology, Manganese oxides, San Luis Potosí, Stable isotopes

Participants

Madondo, Joseph (author)
Canet Miquel, Carles (author)
González Partida, Eduardo (author)
Rodríguez Díaz, Augusto Antonio (author)
Núñez Useche, Fernando (author)
Alfonso Abella, María Pura (author)
Rajabi, Abdorrahman (author)
Pi, Teresa (author)
Blignaut, Lauren (author)
Vafeas, Nicholas (author)