Geochemical and Nd-isotopic compositions of juvenile-type Paleoproterozoic Birimian sedimentary rocks from southeastern West African Craton (Ghana): Constraints on provenance and tectonic setting

doi:10.1016/j.precamres.2017.07.035

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	Geochemical and Nd-isotopic compositions of juvenile-type Paleoproterozoic Birimian sedimentary rocks from southeastern West African Craton (Ghana): Constraints on provenance and tectonic setting
	Asiedu, Daniel K.1; Asong, Samuel 2; Atta-Peters, David 1; Sakyi, Patrick Asamoah 1; Su, Ben-Xun 3; Dampare, Samuel B.4; Anani, Chris Y.1
刊名	PRECAMBRIAN RESEARCH
	2017-10-01
卷号	300 页码:40-52
关键词	Birimian Geochemistry Nd-isotopes Paleoproterozoic Provenance Sedimentary rocks
ISSN号	0301-9268
DOI	10.1016/j.precamres.2017.07.035
文献子类	Article
英文摘要	The Paleoproterozic Birimian Supergroup consists of sedimentary basins composed predominantly of wackes and argillites, and volcanic belts composed predominantly of basaltic rocks. Whole rock geochemical and Nd-isotopic studies were carried out on fine-grained sedimentary rocks (shales and fine-grained sandstones) from one of the Birimian sedimentary basins, the Kumasi basin. The sedimentary rocks are immature in nature, with very little recycled materials. Relative to average early Proterozoic upper continental crust, the Birimian sedimentary rocks are depleted in the alkalis and alkaline earth elements and the high field strength elements, and enriched In transition metals. Chondrite-normalized rare earth element (REE) plots for both the shales and sandstones show fractionated LREE patterns (average La-N/Sm-N = 3.45), with slight negative Eu-anomalies (average Eu/ Eu* = 0.79) and a slightly fractionated HREE patterns (average Gd-N/Yb-N = 1.84). Low to moderate degree of chemical weathering in the sediment source area is indicated by Chemical Index of Alteration values of between 52 and 80. Elemental ratios such as La/Co, Th/Co, Th/Cr, and Eu/Eu* that are critical to provenance suggests that the sediments were derived from rocks of mixed felsic and mafic compositions. Mixing calculations based on the REEs indicate that, the shale is best modeled with a mixture having 62% TTG, 16% granite and 22% basalt whereas the sandstone is almost 100% TTG. The epsilon(Nd) values for the analyzed samples, calculated at the age of deposition (i.e., 2.1 Ga), range from -1.69 to 1.07, suggesting derivation from an undifferentiated source. The Nd-isotopic compositions, together with Eu/Eu* and Th/U values and other trace element characteristics suggest Young Undifferentiated Arc provenance, and this is in agreement with previous studies that show that the Birmian crust is juvenile and little amount of Archean crust is present in the sedimentary rocks. The geochemical and Nd-isotopic systematics further suggest that the bulk of detritus was supplied by adjacent Paleoproterozoic Birimian greenstone belts with only 10% or less contribution from the Archean crust. Trace element characteristics further suggest that deposition took place in an island arc setting.
WOS关键词	PROTEROZOIC CRUSTAL EVOLUTION ; PENNSYLVANIAN-PERMIAN AGE ; U-PB AGES ; 2.1 GA ; METASEDIMENTARY ROCKS ; CONTINENTAL-CRUST ; GREENSTONE-BELT ; SOUTHERN GHANA ; VOLCANIC-ROCKS ; TRACE-ELEMENTS
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000412252600003
资助机构	Office of Research, Innovation and Development of the University of Ghana ; National Natural Science Foundation of China(41522203) ; Office of Research, Innovation and Development of the University of Ghana ; National Natural Science Foundation of China(41522203) ; Office of Research, Innovation and Development of the University of Ghana ; National Natural Science Foundation of China(41522203) ; Office of Research, Innovation and Development of the University of Ghana ; National Natural Science Foundation of China(41522203)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/61961]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者	Sakyi, Patrick Asamoah
作者单位	1.Univ Ghana, Dept Earth Sci, POB LG 58, Legon, Accra, Ghana 2.Sahara Serv, Rue 13-12,Porte 291,06 BP 10382, Ouagadougou 06, Burkina Faso 3.Chinese Acad Sci, State Key Lab Lithospher Evolut, Inst Geol & Geophys, POB 9825, Beijing 100029, Peoples R China 4.Univ Ghana, Sch Nucl & Allied Sci, Legon, Accra, Ghana
推荐引用方式 GB/T 7714	Asiedu, Daniel K.,Asong, Samuel,Atta-Peters, David,et al. Geochemical and Nd-isotopic compositions of juvenile-type Paleoproterozoic Birimian sedimentary rocks from southeastern West African Craton (Ghana): Constraints on provenance and tectonic setting[J]. PRECAMBRIAN RESEARCH,2017,300:40-52.
APA	Asiedu, Daniel K..,Asong, Samuel.,Atta-Peters, David.,Sakyi, Patrick Asamoah.,Su, Ben-Xun.,...&Anani, Chris Y..(2017).Geochemical and Nd-isotopic compositions of juvenile-type Paleoproterozoic Birimian sedimentary rocks from southeastern West African Craton (Ghana): Constraints on provenance and tectonic setting.PRECAMBRIAN RESEARCH,300,40-52.
MLA	Asiedu, Daniel K.,et al."Geochemical and Nd-isotopic compositions of juvenile-type Paleoproterozoic Birimian sedimentary rocks from southeastern West African Craton (Ghana): Constraints on provenance and tectonic setting".PRECAMBRIAN RESEARCH 300(2017):40-52.