DOI: 10.1016/j.epsl.2020.116182
论文题名: Dynamics of a chemically pulsing mantle plume
作者: Taylor R.N. ; Davila-Harris P. ; Branney M.J. ; Ruth Farley E.M. ; Gernon T.M. ; Palmer M.R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 537 语种: 英语
中文关键词: Canary Islands
; geochemistry
; magmatic evolution
; mantle plume
; Pb isotopes
; temporal and spatial volcanism
; Tenerife
英文关键词: Geochemistry
; Thermal plumes
; Canary islands
; Magmatic evolution
; Mantle plume
; Pb isotopes
; Temporal and spatial
; Tenerife
; Isotopes
; chemical composition
; geochemistry
; lead isotope
; magma
; magmatism
; mantle plume
; volcanism
; Canary Islands
; Santa Cruz de Tenerife [(PRV) Canary Islands]
; Spain
; Tenerife
英文摘要: Upwelling plumes from the deep mantle have an impact on the Earth's surface for tens to hundreds of millions of years. During the lifetime of a mantle plume, periodic fluctuations in its composition and temperature have the potential to generate changes in the nature and volume of surface volcanism. We constrain the spatial and temporal scale of compositional changes in a plume using high-resolution Pb isotopes, which identify chemical pulses emerging from the Canary Islands hotspot over the last ∼15 million years (Myr). Surface volcanism spanning ∼ 400 km along the island chain changes composition systematically and synchronously, representing a replenishment of the plume head by a distinct mantle flavour on timescales of 3-5 Myr. These low-frequency compositional changes are also recorded by individual volcanoes, and comprise a sequence of closely-spaced isotopic trajectories. Each trajectory is maintained for ∼1 Myr and is preceded and followed by ∼0.3 Myr transitions to magmas with distinct isotope ratios. Relatively sharp transitions between periods of sustained isotopic stability require discrete yet coherent heterogeneities rising at speeds of ∼100-200 km Myr−1 and extending for ∼150 km vertically in the conduit. The long-term synchronous changes require larger scale isotopic domains extending ∼600 km vertically through in the plume stem. These observations demonstrate that plumes can chemically “pulse” over short and long-timescales reflecting the characteristics and recycling history of the deep mantle. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165307
Appears in Collections: 气候变化与战略
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作者单位: School of Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton, SO14 3ZH, United Kingdom; Instituto Potosino de Investigación Científica y Tecnológica, San Luis Potosí, Mexico; Department of Geography, Geology and the Environment, University of Leicester, United Kingdom
Recommended Citation:
Taylor R.N.,Davila-Harris P.,Branney M.J.,et al. Dynamics of a chemically pulsing mantle plume[J]. Earth and Planetary Science Letters,2020-01-01,537