DOI: 10.1016/j.epsl.2018.02.045
Scopus记录号: 2-s2.0-85043447916
论文题名: Evidence for {100}<011> slip in ferropericlase in Earth's lower mantle from high-pressure/high-temperature experiments
作者: Immoor J. ; Marquardt H. ; Miyagi L. ; Lin F. ; Speziale S. ; Merkel S. ; Buchen J. ; Kurnosov A. ; Liermann H.-P.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 489 起始页码: 251
结束页码: 257
语种: 英语
英文关键词: ferropericlase
; large low shear velocity provinces
; lower mantle
; rheology
; seismic anisotropy
Scopus关键词: Anisotropy
; Chromium compounds
; Crystallography
; Perovskite
; Rheology
; Seismic prospecting
; Seismology
; Shear waves
; Structural geology
; Crystallographic preferred orientations
; Ferropericlase
; Lower mantle
; Lower mantle pressures
; Quantitative interpretation
; Seismic anisotropy
; Shear velocities
; Shear-wave anisotropy
; Shear flow
; experimental study
; high pressure
; high temperature
; lower mantle
; periclase
; rheology
; S-wave
; seismic anisotropy
; velocity structure
; Vesicular stomatitis virus
英文摘要: Seismic anisotropy in Earth's lowermost mantle, resulting from Crystallographic Preferred Orientation (CPO) of elastically anisotropic minerals, is among the most promising observables to map mantle flow patterns. A quantitative interpretation, however, is hampered by the limited understanding of CPO development in lower mantle minerals at simultaneously high pressures and temperatures. Here, we experimentally determine CPO formation in ferropericlase, one of the elastically most anisotropic deep mantle phases, at pressures of the lower mantle and temperatures of up to 1400 K using a novel experimental setup. Our data reveal a significant contribution of slip on {100} to ferropericlase CPO in the deep lower mantle, contradicting previous inferences based on experimental work at lower mantle pressures but room temperature. We use our results along with a geodynamic model to show that deformed ferropericlase produces strong shear wave anisotropy in the lowermost mantle, where horizontally polarized shear waves are faster than vertically polarized shear waves, consistent with seismic observations. We find that ferropericlase alone can produce the observed seismic shear wave splitting in D″ in regions of downwelling, which may be further enhanced by post-perovskite. Our model further shows that the interplay between ferropericlase (causing VSH > VSV) and bridgmanite (causing VSV > VSH) CPO can produce a more complex anisotropy patterns as observed in regions of upwelling at the margin of the African Large Low Shear Velocity Province. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109962
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
There are no files associated with this item.
作者单位: Bayerisches Geoinstitut BGI, University of Bayreuth, Bayreuth, 95440, Germany; University of Utah, 115 So. 1460 E., Salt Lake City, UT 84112-0111, United States; German Research Center for Geosciences GFZ, Potsdam, 14473, Germany; Univ. Lille, CNRS, INRA, ENSCL, UMR 8207, UMET, Unité Matériaux et Transformations, Lille, F-59000, France; Deutsches Elektronen-Synchrotron (DESY), Hamburg, 22607, Germany
Recommended Citation:
Immoor J.,Marquardt H.,Miyagi L.,et al. Evidence for {100}<011> slip in ferropericlase in Earth's lower mantle from high-pressure/high-temperature experiments[J]. Earth and Planetary Science Letters,2018-01-01,489