DOI: 10.1002/2015GL063316
论文题名: Rheology of Mg2GeO4 olivine and spinel harzburgite: Implications for Earth's mantle transition zone
作者: Shi F. ; Zhang J. ; Xia G. ; Jin Z. ; Green H.W.
刊名: Geophysical Research Letters
ISSN: 0094-8782
EISSN: 1944-8513
出版年: 2015
卷: 42, 期: 7 起始页码: 2212
结束页码: 2218
语种: 英语
英文关键词: dislocation creep
; mantle transition zone
; Mg2GeO4 olivine
; Mg2GeO4 spinel
Scopus关键词: Creep
; Elasticity
; Minerals
; Olivine
; Structural geology
; 410-km discontinuity
; Dislocation creep
; Geophysical modeling
; Grain-size reduction
; Low viscosity zone
; Mantle transition zone
; Transformation-Induced
; Uppermost mantle
; Silicate minerals
; abundance
; creep
; dislocation
; grain size
; rheology
; transition zone
; upper mantle
英文摘要: Geophysical modeling requires an upper mantle low-viscosity zone (LVZ); recent results suggest that the LVZ could be within the mantle transition zone (MTZ) or above it, depending on boundary conditions. The rheology of the olivine-dominated uppermost mantle is well constrained experimentally but not the MTZ. Here we report first-time measurement of the rheology of Mg2GeO4 spinel (analogue of ringwoodite, the dominant mineral of the lower MTZ) in the dislocation creep regime and compare it with that of Mg2GeO4 olivine. In both cases, we incorporate 15-20% pyroxene, the second most abundant mineral in the upper mantle to provide a realistic comparison of rock rheologies. Under similar conditions, spinel-dominated material is about twice as strong as olivine-dominated material. Our results suggest that unless H2O weakening of ringwoodite or phase-transformation-induced grain size reduction occurs in the lower MTZ, it will be more viscous than above the 410 km discontinuity. ©2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928704769&doi=10.1002%2f2015GL063316&partnerID=40&md5=303755697ea03e3d0ee0cdbf65375f87
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8398
Appears in Collections: 科学计划与规划 气候变化与战略
There are no files associated with this item.
作者单位: State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, China
Recommended Citation:
Shi F.,Zhang J.,Xia G.,et al. Rheology of Mg2GeO4 olivine and spinel harzburgite: Implications for Earth's mantle transition zone[J]. Geophysical Research Letters,2015-01-01,42(7).