Geodynamic Evolution of the East African Superplume: Insights From Volcanism in the Western Turkana Basin

doi:10.1029/2023JB026755

NIGPAS OpenIR

	Geodynamic Evolution of the East African Superplume: Insights From Volcanism in the Western Turkana Basin
通讯作者	Cai, Yue(cai@nigpas.ac.cn) ; Mana, Sara(smana@salemstate.edu)
	Cai, Yue 1,2; Mana, Sara 3; Cox, Stephen E.4; Beck, Catherine C.5; Feibel, Craig 6; Hanley, Jean 4; Liu, Tanzhuo 4; Bolge, Louise 4; Hemming, Sidney 4,7; Goldstein, Steven L.4,7
	2023-09-01
发表期刊	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
ISSN	2169-9313
卷号	128 期号:9 页码:24
摘要	There is a consensus that volcanism along the East African Rift System (EARS) is related to plume activities. However, because of our limited knowledge of the local lithospheric mantle, the dynamics of the plume are poorly constrained by magma chemistry. The Turkana Basin is one of the best places to study plume-related volcanism because the lithospheric mantle there is unusually thin. New Ar-Ar geochronology and geochemical data on lavas from western Turkana show that Eocene volcanics have relatively low Pb-206/Pb-204 (<19.1) and high epsilon Nd (>3.78). Their relatively high Ba/Rb (35-78) ratios suggest contributions from the shallow lithospheric mantle. Oligo-Miocene Turkana volcanics have HIMU- and EMI- type enriched mantle signatures with overall lower Ba/Rb ratios, which is consistent with partial melting of plume material. Pliocene and younger Turkana volcanics have low Ba/Rb and Sr-Nd-Pb isotope ratios that resemble those of Ethiopian volcanics with elevated He-3/He-4 ratios. This temporal variation can be reconciled with a layered plume model where an outer layer of ancient recycled oceanic crust and sediment overlies more primitive lower mantle material. Beneath Ethiopia, the outer layer of the plume is either missing or punctured by the delamination of the thicker overlying lithospheric mantle at ca. 30 Ma, an event that would have facilitated the rapid upwelling of the inner portion of the plume and triggered the Ethiopian flood volcanism. The outer layer of the plume may be thicker in the southern EARS, which could explain the occurrence of young HIMU- and EMI-type volcanics with primordial noble gas signatures.
关键词	African Superplume Ar-40/Ar-39 geochronology lead isotopes neodymium isotopes strontium isotopes mantle plume HIMU EMI East African Rift System (EARS)
DOI	10.1029/2023JB026755
收录类别	SCI
语种	英语
关键词[WOS]	CONTINENTAL FLOOD VOLCANISM ; PLUME DYNAMICS BENEATH ; UPPER-MANTLE BENEATH ; RIFT SYSTEM ; KENYA RIFT ; LITHOSPHERIC MANTLE ; ISOTOPE SYSTEMATICS ; NORTHERN KENYA ; GEOCHEMICAL EVIDENCE ; CENOZOIC MAGMATISM
资助项目	We thank Francis Ekai Ikai for his assistance during the fieldwork; Tanya Furman for contributing precious samples to this study and commenting on an early draft of the paper, which greatly improved the manuscript; Isabella Manighetti, Catherine Chauvel, a[EAR-GeoPRISMS 1457293] ; We thank Francis Ekai Ikai for his assistance during the fieldwork; Tanya Furman for contributing precious samples to this study and commenting on an early draft of the paper, which greatly improved the manuscript; Isabella Manighetti, Catherine Chauvel, a[EAR-1714892] ; We thank Francis Ekai Ikai for his assistance during the fieldwork; Tanya Furman for contributing precious samples to this study and commenting on an early draft of the paper, which greatly improved the manuscript; Isabella Manighetti, Catherine Chauvel, a[EAR 2021591] ; NSF ; Columbia Global Centers ; Storke Endowment of the Columbia University Department of Earth and Environmental Sciences[NACOSTI/P/22/17095] ; Turkana Miocene Project (TMP)
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:001077413700008
项目资助者	We thank Francis Ekai Ikai for his assistance during the fieldwork; Tanya Furman for contributing precious samples to this study and commenting on an early draft of the paper, which greatly improved the manuscript; Isabella Manighetti, Catherine Chauvel, a ; NSF ; Columbia Global Centers ; Storke Endowment of the Columbia University Department of Earth and Environmental Sciences ; Turkana Miocene Project (TMP)
出版者	AMER GEOPHYSICAL UNION
文献类型	期刊论文
条目标识符	http://ir.nigpas.ac.cn/handle/332004/43168
专题	中国科学院南京地质古生物研究所
通讯作者	Cai, Yue; Mana, Sara
作者单位	1.Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, State Key Lab Palaeobiol & Stratig, Nanjing, Peoples R China 2.Chinese Acad Sci, Ctr Excellence Life & Paleoenvironm, Nanjing, Peoples R China 3.Salem State Univ, Dept Geol Sci, Salem, MA 01970 USA 4.Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY USA 5.Hamilton Coll, Geosci Dept, Clinton, NY USA 6.Rutgers State Univ, Dept Earth & Planetary Sci, New Brunswick, NJ USA 7.Columbia Univ, Dept Earth & Environm Sci, Palisades, NY USA
第一作者单位	中国科学院南京地质古生物研究所
通讯作者单位	中国科学院南京地质古生物研究所
推荐引用方式 GB/T 7714	Cai, Yue,Mana, Sara,Cox, Stephen E.,et al. Geodynamic Evolution of the East African Superplume: Insights From Volcanism in the Western Turkana Basin[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2023,128(9):24.
APA	Cai, Yue.,Mana, Sara.,Cox, Stephen E..,Beck, Catherine C..,Feibel, Craig.,...&Goldstein, Steven L..(2023).Geodynamic Evolution of the East African Superplume: Insights From Volcanism in the Western Turkana Basin.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,128(9),24.
MLA	Cai, Yue,et al."Geodynamic Evolution of the East African Superplume: Insights From Volcanism in the Western Turkana Basin".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 128.9(2023):24.