DOI: 10.1016/j.epsl.2021.117130
论文题名: Tracing material contributions from Saint Helena plume to the South Mid-Atlantic ridge system
作者: Zhang H. ; Yan Q. ; Li C. ; Shi X. ; Yang Y. ; Wang G. ; Hua Q. ; Zhu Z. ; Zhang H. ; Zhao R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 572 语种: 英语
中文关键词: mantle plume
; mantle sources
; ridge-hotspot interaction
; south MAR
英文关键词: Basalt
; Boundary layers
; Structural geology
; Thermal plumes
; Evolution history
; Flow direction
; Fracture zone
; Geological evolution
; Hot spot
; Mantle plume
; Mantle source
; Mid Atlantic Ridge
; Ridge-hotspot interaction
; South MAR
; Submarine geology
英文摘要: Ridge-hotspot interaction plays a significant role during the whole geological evolution history of Atlantic Ocean. Whether the ongoing spreading south Mid-Atlantic ridge (SMAR) is affected by those mantle plumes gradually migrating away from the ridge or not, need to be further explored. Here we investigate the chemical components of basalts from the SMAR 13.2°S–24.2°S segments, which contain the Saint Helena plume-like chemical traces that have enriched incompatible element ratios (e.g., K2O/TiO2, Nb/Zr, (La/Sm)N) and higher 87Sr/86Sr, 206Pb/204Pb and lower 143Nd/144Nd and 176Hf/177Hf relative to those plume-free SMAR MORBs. These, combining with geophysical data and off-axis seamounts data, show that the spatial scope of Saint Helena hotspot influence on SMAR system is bounded by the Cardno fracture zone (∼14.2°S) to the north and the Trinidade fracture zone (∼20.8°S) to the south. Furthermore, this study infers possible flow directions of the Saint Helena hotspot materials from Cardno seamount toward the SMAR system, and the ends of these flows directions are at the SMAR 14.2°S–20.8°S segments, where the basalts have stronger Saint Helena plume-related geochemical signals, and the ridge axes keep shallower axis depth and lower mantle Bouguer gravity anomaly relative to the other segments. Finally, we develop a sketch-like model to depict material flow styles from Saint Helena plume to the actively spreading SMAR regions along a sloping rheologically boundary layer at the lithospheric bottom. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165748
Appears in Collections: 气候变化与战略
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作者单位: Key Laboratory of Marine Geology and Metallogeny, First Institute of Oceanography, MNR, Qingdao, Shandong 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266061, China; National Deep Sea Center, MNR, Qingdao, 266061, China; Chengdu University of Technology, Chengdu, 610059, China; College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Recommended Citation:
Zhang H.,Yan Q.,Li C.,et al. Tracing material contributions from Saint Helena plume to the South Mid-Atlantic ridge system[J]. Earth and Planetary Science Letters,2021-01-01,572