Molybdenum isotopic composition of molybdenite and the fertility potential of the Ekomédion U–Mo prospect, SW Cameroon

Journal of Geosciences

article

Victor Fonabe Embui¹  Cheo Emmanuel Suh³  Bernd Lehmann⁵  Lukas Ackerman⁶ 

[1] Ore Treatment Laboratory, Institute of Geological and Mining Research;Department of Mining and Mineral Engineering, National Higher Polytechnic Institute, University of Bamenda;Department of Geology, University of Buea;Department of Geology, Mining and Environmental Science, University of Bamenda;Mineral Resources, Technical University of Clausthal;Institute of Geology of the Czech Academy of Sciences;Czech Geological Survey

关键词: granite;    pegmatite;    molybdenum isotopes;    geochemistry;    redox-state;    Cameroon;   

DOI  :  10.3190/jgeosci.363

学科分类：自动化工程

来源: Ceska Geologicka Spolecnost / Czech Geological Society

【 摘 要 】

We present Mo isotope data for molybdenite from the Ekomédion U–Mo prospect, SW Cameroon, a Late Neoproterozoicgranite–pegmatite–quartz vein system. Disseminated and veinlet-controlled molybdenite in granite and pegmatitic podsyields a narrow range of δ98Mo values from –0.06 to +0.24 ‰, with two overlapping populations of +0.03±0.07 ‰(n=4) in granite, and slightly heavier of +0.11±0.10 ‰ (n = 5) in pegmatite. By contrast, molybdenite from a quartz–muscovite vein has an isotopically heavy δ98Mo value of +1.61 ‰. We interpret this trend from granite through pegmatiteto vein system towards isotopically heavy Mo to reflect the fractionation of an evolving magmatic–hydrothermal system.Furthermore, the LREE-enriched bulk-rock patterns with largely negative Eu anomalies and the overall enrichment ofHREE in zircon indicate plagioclase fractionation as the dominant petrogenetic process during melt evolution. Furthermore, the presence of accessory ilmenite indicates relatively reducing conditions of the melt system, unfavorable forsignificant Mo accumulation. Therefore, the Ekomédion granite system seems to have limited economic potential formolybdenum despite the advanced degree of magmatic evolution.

【 授权许可】

CC BY