DOI: 10.1002/2017JE005371
Scopus记录号: 2-s2.0-85042548021
论文题名: A Geophysical Perspective on the Bulk Composition of Mars
作者: Khan A. ; Liebske C. ; Rozel A. ; Rivoldini A. ; Nimmo F. ; Connolly J.A.D. ; Plesa A.-C. ; Giardini D.
刊名: Journal of Geophysical Research: Planets
ISSN: 21699097
出版年: 2018
卷: 123, 期: 2 起始页码: 575
结束页码: 611
语种: 英语
英文关键词: core size
; dissipation
; interior structure
; mantle temperature
; Mars
; rheology
Scopus关键词: Calluna vulgaris
英文摘要: We invert the Martian tidal response and mean mass and moment of inertia for chemical composition, thermal state, and interior structure. The inversion combines phase equilibrium computations with a laboratory-based viscoelastic dissipation model. The rheological model, which is based on measurements of anhydrous and melt-free olivine, is both temperature and grain size sensitive and imposes strong constraints on interior structure. The bottom of the lithosphere, defined as the location where the conductive geotherm meets the mantle adiabat, occurs deep within the upper mantle (∼200–400 km depth) resulting in apparent upper mantle low-velocity zones. Assuming an Fe-FeS core, our results indicate (1) a mantle with a Mg# (molar Mg/Mg+Fe) of ∼0.75 in agreement with earlier geochemical estimates based on analysis of Martian meteorites; (2) absence of bridgmanite- and ferropericlase-dominated basal layer; (3) core compositions (15–18.5 wt% S), core radii (1,730–1,840 km), and core-mantle boundary temperatures (1620–1690°C) that, together with the eutectic-like core compositions, suggest that the core is liquid; and (4) bulk Martian compositions with a Fe/Si (weight ratio) of 1.66–1.81. We show that the inversion results can be used in tandem with geodynamic simulations to identify plausible geodynamic scenarios and parameters. Specifically, we find that the inversion results are largely reproducible by stagnant lid convection models for a range of initial viscosities (∼1018–1020 Pa s) and radioactive element partitioning between crust and mantle around 0.01–0.1. The geodynamic models predict a mean surface heat flow between 15 and 25 mW/m2. ©2017. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114623
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Geophysics, ETH Zürich, Zurich, Switzerland; Institute of Geochemistry and Petrology, ETH Zürich, Zurich, Switzerland; Royal Observatory of Belgium, Brussels, Belgium; Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, United States; German Aerospace Center (DLR), Berlin, Germany
Recommended Citation:
Khan A.,Liebske C.,Rozel A.,et al. A Geophysical Perspective on the Bulk Composition of Mars[J]. Journal of Geophysical Research: Planets,2018-01-01,123(2)