Geochemistry and geochronology of the Sierra de Gomez Limestone-hosted U deposit, Chihuahua: Implications for distribution of Rio Grande rift mineral deposits in northern Mexico


Por: Villarreal-Fuentes, Janet, Levresse, Gilles, Nieto-Samaniego, Angel F., Alexandre, Paul, Corona-Esquivel, Rodolfo

Publicada: 1 jul 2016
Resumen:
Uranium deposits form in a variety of settings. They are partially controlled by the secular evolution of Earth processes, including deposits in extension-related settings such as the intra-cratonic Rio Grande rift. Plio-Quaternary volcanism, mineral deposits, and hydrothermal spots occur along the Chihuahua Central Graben. The age of the Sierra de Gomez U-deposit is 1.8 Ma (based on LA-MC-ICP-MS dating on a uranophane monocrystal), which is contemporaneous with the late mineralization event of the Peña Blanca U-deposit, as well as Rio Grande Rift (RGR)-type deposits in Chihuahua and intraplate volcanism. Studies of fluid inclusions in fluorite and late calcite indicate the presence of hydrocarbons and CH4-rich brine. Homogenization temperatures range from 87 to 112 °C, and the mean composition (2.0 mol NaCl and 0.3 mol CaCl with CH4) is comparable to mineralizing brines in MVT deposits and carbonated hydrocarbon reservoirs. Evolution of C and O stable isotopic values for the calcite cement in the Sierra de Gomez Limestone-hosted U deposit illustrates that two separate calcite precipitation events occurred: (1) travertine filling karst structures in the presence of meteoric water and (2) U mineralization during deep hydrothermal fluid circulation that included interactions with a heat source and basement leaching. In a regional context, a metallogenic model suggests that the Chihuahua Trough area is deep enough to generate fluid migration by hydrothermal and/or compaction processes through RGR extensional faults until a favorable trapping horizon is reached. This causes uranium precipitation because water/rock interaction processes generate a local redox barrier. © 2016 Elsevier B.V.

Filiaciones:
Villarreal-Fuentes, Janet:
 Univ Nacl Autonoma Mexico, Ctr Geociencias, Blvd Juriquilla 3001, Queretaro 76230, Mexico

Levresse, Gilles:
 Univ Nacl Autonoma Mexico, Ctr Geociencias, Blvd Juriquilla 3001, Queretaro 76230, Mexico

Nieto-Samaniego, Angel F.:
 Univ Nacl Autonoma Mexico, Ctr Geociencias, Blvd Juriquilla 3001, Queretaro 76230, Mexico

Alexandre, Paul:
 Queens Univ Ontario, Toronto, ON, Canada

Corona-Esquivel, Rodolfo:
 Univ Nacl Autonoma Mexico, Inst Geol, Mexico City, DF, Mexico
ISSN: 01691368
Editorial
Elsevier, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, Países Bajos
Tipo de documento: Article
Volumen: 76 Número:
Páginas: 19-34
WOS Id: 000377831900002

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