DOI: 10.1038/ngeo2669
论文题名: Remote sensing evidence for an ancient carbon-bearing crust on Mercury
作者: Peplowski P.N. ; Klima R.L. ; Lawrence D.J. ; Ernst C.M. ; Denevi B.W. ; Frank E.A. ; Goldsten J.O. ; Murchie S.L. ; Nittler L.R. ; Solomon S.C.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2016
卷: 9, 期: 4 起始页码: 273
结束页码: 276
语种: 英语
Scopus关键词: carbon
; concentration (composition)
; crater
; crust
; crustal evolution
; graphite
; magma
; Mercury (planet)
; near infrared
; remote sensing
; spacecraft
英文摘要: Mercury's global surface is markedly darker than predicted from its measured elemental composition. The darkening agent, which has not been previously identified, is most concentrated within Mercury's lowest-reflectance spectral unit, the low-reflectance material. This low-reflectance material is generally found in large impact craters and their ejecta, which suggests a mid-to-lower crustal origin. Here we present neutron spectroscopy measurements of Mercury's surface from the MESSENGER spacecraft that reveal increases in thermal-neutron count rates that correlate spatially with deposits of low-reflectance material. The only element consistent with both the neutron measurements and visible to near-infrared spectra of low-reflectance material is carbon, at an abundance that is 1-3 wt% greater than surrounding, higher-reflectance material. We infer that carbon is the primary darkening agent on Mercury and that the low-reflectance material samples carbon-bearing deposits within the planet's crust. Our findings are consistent with the formation of a graphite flotation crust from an early magma ocean, and we propose that the heavily disrupted remnants of this ancient layer persist beneath the present upper crust. Under this scenario, Mercury's globally low reflectance results from mixing of the ancient graphite-rich crust with overlying volcanic materials via impact processes or assimilation of carbon into rising magmas during secondary crustal formation. © 2016 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106046
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States; Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC, United States; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States
Recommended Citation:
Peplowski P.N.,Klima R.L.,Lawrence D.J.,et al. Remote sensing evidence for an ancient carbon-bearing crust on Mercury[J]. Nature Geoscience,2016-01-01,9(4)