Provenance,depositional process,and tectonic setting of gold placer from the Bétaré-Oya Gold District(East-Cameroon,Central Africa)along the Precambrian Sanaga fault  

作　　者：Milan Stafford Tchouatcha Arnaud Patrice Kouske Primus Azinwi Tamfuh Epimarc Gildas Tchameni Ngouabe Gerald Chuye Yango 

机构地区：[1]Department of Earth Sciences,Faculty of Science,University of Dschang,P.O.Box 67,Dschang,Cameroon [2]University Institute of Technology,University of Douala,P.O.Box 8698,Douala,Cameroon [3]Department of Mining and Mineral Engineering,National Higher Polytechnic Institute,University of Bamenda,P.O.Box 39,Bambili,Cameroon [4]Department of Soil Science,Faculty of Agronomy and Agricultural Sciences,University of Dschang,P.O.Box 222,Dschang,Cameroon [5]Department of Mining and Geology,School of Geology and Mining Engineering,University of Ngaoundere,P.O.Box 115,Meiganga,Cameroon

出　　处：《International Journal of Sediment Research》2023年第4期576-596,共21页国际泥沙研究（英文版）

摘　　要：The Bétaré-Oya Gold District is one of the three gold districts in East Cameroon with varied types of mining.The study site is an open-cast mine located in an alluvial plain.The strata succession globally consists of two positive sequences represented by three facies associations and seven lithofacies:massive clast-supported(Gcm),massive trough-cross bedded(Gtm),and massive matrix-supported(Gmm)conglomerates;massive sands(Sm);and massive(Fm),heterolothic(Fhl),and convolute and heterolithic(Fhlc)clays.The facies analysis indicates deposition after a recent tectonic event creating a depression,followed by a rapid deposition of varied facies and energies of sedimentation with fluvial and gravity inputs.The deposits come from proximal to distal sources but more proximal.The identified heavy mineral or accompanying minerals reveal a plutonic source(tourmaline sometimes folded),a volcanic source(olivine or clino-pyroxene with cracks),and a metamorphic source(sillimanite,andalusite,and staurolite).In the pan concentrates of placer with high silver(Ag)concentration(100 ppm)are also associated with relative abundance of lead(Pb)(17.8 ppm),zinc(Zn)(27 ppm),and low levels of copper(Cu)(3.1 ppm).The concentration and distribution of some element ratios,such as thorium/scandium(Th/Sc),chromium/thorium(Cr/Th),and europium anomaly(Eu/Eu*),rare earth elements(REEs)and aluminum oxide/titanium dioxide(Al2O3/TiO2)vs.silicon dioxide(SiO2)plots for the studied sediment indicate heterogeneous sources of rocks with dominance of felsic sources.The discriminant diagram reveals a recycled or sedimentary provenance of the deposited sediments.The tectonic setting plot indicates a collision tectonic setting which is consistent with the Precambrian history of the study area which belongs to the Pan-African North-Equatorial fold Belt.The gold deposits in the B etar e-Oya area probably derive from several sources,such as a vein source(from magmatic and metamorphic processes of the Neoproterozoic age)and a sedimentary source(from remobilizatio

关 键 词：PROVENANCE Gold placer SEDIMENTOLOGY Geochemistry Betare-Oya Cameroon 

分 类 号：P618.51[天文地球—矿床学]