Vanadium mineralization at Los Chihuidos sediment-hosted Cu-V deposit,Neuquén Basin,Argentina:An approach to vanadium ore forming processes  

作　　者：Ana L.Rainoldi Daniel Beaufort Marta B.Franchini Adolfo Giusiano Sabine Petit Patricia Patrier M.Josefina Pons 

机构地区：[1]Dpto.de Geología,Universidad Nacional del Sur(UNS),8000 Bahía Blanca,Argentina [2]Consejo Nacional de Investigaciones Científicas y Técnicas,Centro Patagónico de Estudios Metalogenéticos,Argentina [3]Universitéde Poitiers,IC2MP,CNRS-UMR 7285,Hydrasa,F-86022 Poitiers Cedex,France [4]Universidad Nacional del Comahue,Facultad de Ingeniería,Departamento de Geología y Petróleo,8300 Neuquén,Argentina [5]Consultant Geologist,8300 Neuquén,Argentina [6]Universidad Nacional de Río Negro,Instituto de Investigación en Paleobiología y Geología,Río Negro,Argentina

出　　处：《Geoscience Frontiers》2024年第1期225-246,共22页地学前缘（英文版）

基　　金：supported by European Commission through its Erasmus Mundus Internship program,which allowed ALR to conduct the clay mineral analysis at the IC2MP (Universitéde Poitiers),FONCyT (PICT No.2010-2608);CONICET (PIP No.6043,PIP No.1083,and PIP No.330);Universidad Nacional del Comahue (PIP No.04/I167);Universidad Nacional del Sur (SECyT through its Internship program in Research and PGI 24/H144);support from the European Union (ERDF)and Région Nouvelle Aquitaine.

摘　　要：Vanadium mineralization at Los Chihuidos deposit of the Neuquén Basin is linked to the development of a redox front system related to the inflow of hydrocarbons into the red sandstone of the Huincul Formation.Interaction of hydrocarbons with oxidized red beds and connate water generated redox reactions where hematite was dissolved due to iron reduction resulting in the discoloration of the red strata.At the contact between oxidized red sandstone and reduced white sandstone,precipitation of specific mineral phases resulted in the V ore with minor amounts of Cu.With the implementation of the redox interface,abundant V-montmorillonite and V-hematite precipitated at the more oxidizing conditions and Cu-V-corrensite-type at the more reducing conditions of the redox front.As the redox front advanced with fluids constantly migrating into the reservoir,more reducing conditions were stablished,promoting chloritization and minor illitization with V-Cu incorporation and continuous upgrading of the ore.Main ore mineralogy consists of clay minerals including V-bearing montmorillonite,Cu-V-corrensite-type,V-di-trioctahedral chlorite and Cu-tri-trioctahedral chlorite with minor V-illite-smectite mixed-layer minerals and associated secondary V-hematite.Chloritization over illitization was favored due to high amounts of Fe and Mg in detrital clasts and in connate fluids and by low K availability related to low amounts of detrital K-feldspar.The spatial transition of V and/or Cu bearing clay minerals observed through the mineralized redox front at Los Chihuidos deposit(kaolinite→smectite→illite/smectite→corrensite-type→di-trioctahedral-chlorite→tri-trioctahedral-chlorite)and the related variation of V-Cu concentrations in bulk rock are indicative of increasing pH and decreasing Eh of resident solutions from red to white sandstones during the hypogene mineralization process.Late influx of Cu-rich oxidized basinal brines precipitated main copper ore with Cu-sulfides in the white sandstone up to the contact with the redox

关 键 词：Clay minerals V-chlorite Redox front BLEACHING Hydrocarbons 

分 类 号：P618.51[天文地球—矿床学] P618.66[天文地球—地质学]