| DOI: | 10.1002/2015GL065459
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| 论文题名: | Compositional dependence of lower crustal viscosity |
| 作者: | Shinevar W.J.; Behn M.D.; Hirth G.
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| 刊名: | Geophysical Research Letters
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| ISSN: | 0094-9121
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| EISSN: | 1944-8852
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| 出版年: | 2015
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| 卷: | 42, 期:20 | | 起始页码: | 8333
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| 结束页码: | 8340
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| 语种: | 英语
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| 英文关键词: | andesite
; crustal composition
; crustal viscosity
; flow laws
; lower crust
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| Scopus关键词: | Aggregates
; Feldspar
; Free energy
; Gibbs free energy
; Mixing
; Tectonics
; andesite
; Compositional dependence
; Continental crusts
; Crustal composition
; Flow law
; Gibbs free energy minimization
; Lower crust
; Pressure and temperature
; Viscosity
; andesite
; basalt
; continental crust
; deformation
; feldspar
; Gibbs free energy
; glacioisostasy
; lower crust
; mineral
; mixing
; paleolimnology
; Postglacial
; postseismic process
; quartz
; rheology
; shoreline change
; viscosity
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| 英文摘要: | We calculate the viscosity structure of the lower continental crust as a function of its bulk composition using multiphase mixing theory. We use the Gibbs free-energy minimization routine Perple-X to calculate mineral assemblages for different crustal compositions under pressure and temperature conditions appropriate for the lower continental crust. The effective aggregate viscosities are then calculated using a rheologic mixing model and flow laws for the major crust-forming minerals. We investigate the viscosity of two lower crustal compositions: (i) basaltic (53 wt % SiO2) and (ii) andesitic (64 wt % SiO2). The andesitic model predicts aggregate viscosities similar to feldspar and approximately 1 order of magnitude greater than that of wet quartz. The viscosity range calculated for the andesitic crustal composition (particularly when hydrous phases are stable) is most similar to independent estimates of lower crust viscosity in actively deforming regions based on postglacial isostatic rebound, postseismic relaxation, and paleolake shoreline deflection. Key Points Crustal viscosity estimates are most similar to predictions for an andesitic lower continental crust The andesitic model predicts aggregate viscosities similar to feldspar An andesitic crust is ~1 order of magnitude less viscous than basaltic crust © 2015. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946593099&doi=10.1002%2f2015GL065459&partnerID=40&md5=5082fedc0fa2c67c23115eb5f7424720
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/8737
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| Appears in Collections: | 科学计划与规划
气候变化与战略
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作者单位: | Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, United States
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| Recommended Citation: | |
Shinevar W.J.,Behn M.D.,Hirth G.. Compositional dependence of lower crustal viscosity[J]. Geophysical Research Letters,2015-01-01,42(20).
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