DOI: 10.1016/j.tecto.2020.228476
论文题名: Possible tectonic patterns along the eastern margin of Gondwanaland from numerical studies of mantle convection
作者: Yoshida M. ; Saito S. ; Yoshizawa K.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2020
卷: 787 语种: 英语
中文关键词: Continental breakup
; Continental margin
; Gondwanaland
; Mantle convection
; Numerical simulation
; Zealandia
英文关键词: Shear flow
; Buoyancy fluxes
; High temperature
; Mantle convection
; Shear velocities
; Subduction zones
; Tectonic patterns
; Temperature anomaly
; Thermal structure
; Tectonics
; Gondwana
; hot spot
; mantle convection
; mantle plume
; numerical method
; subduction zone
; tectonic structure
; temperature anomaly
; thermal structure
; Africa
; Atlantic islands
; Pacific Ocean
; Pacific Ocean (South)
英文摘要: Two end-member scenarios have been proposed for the tectonic situation along the eastern margins of Gondwanaland before Zealandia was formed ca. 100 million years ago (Ma), namely: (1) A subduction zone located far from the eastern margin of Zealandia, wherein Zealandia may have separated from Gondwanaland by plume push of an active hotspot plume.; (2) A subduction zone located along the eastern margin of Gondwanaland, wherein Zealandia possibly separated from Gondwanaland via trench/subduction retreat. Assuming that the thermal structure of the deep mantle and source of hotspot plumes remained relatively stationary over the last hundred million years, major hotspot plumes with a large buoyancy flux did not exist under Zealandia; the eastern margins of Gondwanaland were far from two large low-shear-velocity provinces under the Africa–Atlantic and South Pacific regions. Herein, through numerical studies of three-dimensional global mantle convection, we examined the mantle convection and surface tectonic patterns at ~100 Ma. The present model considered the real configuration of Gondwanaland at the model surface to observe long-term variations of mantle convection and the resulting surface tectonic conditions. The results demonstrate that the extensive subduction zones developed preferentially along the eastern margin of Gondwanaland when the temperature anomaly of the lower mantle was primarily dominated by high-temperature regions under present-day Africa–Atlantic and South Pacific regions. The results of this study support one of the proposed hypotheses, where the breakup at the eastern margins of Gondwanaland at ~100 Ma occurred via trench/subduction retreat. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170741
Appears in Collections: 气候变化与战略
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作者单位: Geophysical Research Group, Research Center for Volcanoes and Earth's Interior, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan; Institute for Marine-Earth Exploration and Engineering, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan; Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
Recommended Citation:
Yoshida M.,Saito S.,Yoshizawa K.. Possible tectonic patterns along the eastern margin of Gondwanaland from numerical studies of mantle convection[J]. Tectonophysics,2020-01-01,787