Geochemical,mineralogical,and petrological characteristics of the Cretaceous coal from the middle Benue Trough Basin,Nigeria:Implication for coal depositional environments  

作　　者：Segun A.Akinyemi James C.Hower Henry Y.Madukwe Bemgba B.Nyakuma Mohammed B.Nasirudeen Timileyin A.Olanipekun Rabelani Mudzielwana Mugera W.Gitari Luis F.O.Silva 

机构地区：[1]Department of Geology,Faculty of Science,Ekiti State University,P.M.B 5363,Ado Ekiti,Ekiti State,Nigeria [2]Energy,Environmental and Nanosciences Group,Department of Geology,Ekiti State University,P.M.B 5363,Ado-Ekiti,Ekiti State,Nigeria [3]University of Kentucky,Centre for Applied Energy Research,2540 Research,Park Drive,Lexington,KY,40511,USA [4]Department of Earth&Environmental Sciences,University of Kentucky,Lexington,KY,40506,USA [5]Department of Chemistry,Faculty of Sciences,Benue State University,P.M.B.102119,Makurdi,Benue State,Nigeria [6]Department of Chemistry,Faculty of Science,Federal University of Lafia,P.M.B.146,Lafia,Nasarawa State,Nigeria [7]Institute of Earth and Environmental Sciences,Albert Ludwigs Universitat Freiburg,Albert Straße 23-B,79104,Freiburg [8]Breisgau,Germany [9]Department of Ecology and Resources Management,University of Venda,Private Bag,X5050,Thohoyandou,0950,Limpopo,South Africa [10]Department of Civil and Environmental,Universidad de la Costa,Calle 58#55-66,080002,Barranquilla,Atlantico,Colombia

出　　处：《Energy Geoscience》2022年第3期300-313,共14页能源地球科学（英文）

摘　　要：The Benue Trough Basin (BTB) of Nigeria is geologically and geo-morphologically subdivided into upper,middle, and lower segments. The BTB is the subject of geological research due to its rich coal depositsthat have the potential for oil and gas. The purpose of the present study is to examine the origins,depositional environments, and thermal history of the selected coals and the processes that influencetheir quality. Coal samples from different open cast coal mines in the middle BTB were examined usingproximate and ultimate, x-ray diffraction (XRD), x-ray fluorescence (XRF), laser ablation induced coupledplasma (LA-ICPMS), and petrographical analyses. The coal samples contained mainly quartz, kaolinite,and organic carbon. The XRD spectra peaks revealed the triclinic and monoclinic structure of kaolin. TheSiO2/Al2O3 ratios confirmed the dominance of quartz and kaolinite. The Ni/Co versus V/Cr, Cu/Zn, and V/Mo values in the studied coals suggest oxic depositional environments, whereas the V/(Ni þ V) and V/(V þ Cr) values indicate oxic to suboxic conditions. The Ce/Ce* values are slightly below 1, which indicates a suboxic depositional environment. Maceral texture is indicative of transformations from subbituminous to high volatile C or B bituminous coal. The maceral components and mineral matter(10%) of the studied coals imply deposition in the planar margin mire, and a river system of planarmargin mire environments, respectively. The high gelification index (GI) and tissue preservation index(TPI) values indicate peat accumulation developed within a wet forest swamp. The ternary diagram ofthe maceral component suggests deposition in a wet moor environment with intermittent moderate tohigh flooding episodes. The studied coals are sub-hydrous vitrinite inferring hydrogen-poor and thermally immature characteristics. The low V and Ni contents, low H/C and high O/C, indicate Type IIIterrestrial organic matter with the potential to generate gaseous hydrocarbons. The investigated coalswere deposited by the river within

关 键 词：COAL MACERAL Trace elements MINERALOGY Depositional environments 

分 类 号：P618.13[天文地球—矿床学]