DOI: 10.1016/j.epsl.2018.02.013
Scopus记录号: 2-s2.0-85045579892
论文题名: Were chondrites magnetized by the early solar wind?
作者: Oran R. ; Weiss B.P. ; Cohen O.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 492 起始页码: 222
结束页码: 231
语种: 英语
英文关键词: asteroids and planetesimals
; magnetohydrodynamics
; meteorites
; paleomagnetism
; solar wind and stellar winds
Scopus关键词: Electromagnetic field effects
; Geomagnetism
; Magnetohydrodynamics
; Meteorites
; Natural resources management
; Piles
; Solar system
; Stars
; Alternative hypothesis
; Astronomical observation
; Carbonaceous chondrites
; Chondritic meteorites
; Natural remanent magnetization
; paleomagnetism
; Solar system formation
; Stellar wind
; Solar wind
; asteroid
; carbonaceous chondrite
; chondrite
; magnetization
; magnetohydrodynamics
; meteorite
; paleomagnetism
; remanent magnetization
; solar wind
英文摘要: Chondritic meteorites have been traditionally thought to be samples of undifferentiated bodies that never experienced large-scale melting. This view has been challenged by the existence of post-accretional, unidirectional natural remanent magnetization (NRM) in CV carbonaceous chondrites. The relatively young inferred NRM age [∼10 million years (My) after solar system formation] and long duration of NRM acquisition (1–106 y) have been interpreted as evidence that the magnetizing field was that of a core dynamo within the CV parent body. This would imply that CV chondrites represent the primitive crust of a partially differentiated body. However, an alternative hypothesis is that the NRM was imparted by the early solar wind. Here we demonstrate that the solar wind scenario is unlikely due to three main factors: 1) the magnitude of the early solar wind magnetic field is estimated to be <0.1 μT in the terrestrial planet-forming region, 2) the resistivity of chondritic bodies limits field amplification due to pile-up of the solar wind to less than a factor of 3.5 times that of the instantaneous solar wind field, and 3) the solar wind field likely changed over timescales orders of magnitude shorter than the timescale of NRM acquisition. Using analytical arguments, numerical simulations and astronomical observations of the present-day solar wind and magnetic fields of young stars, we show that the maximum mean field the ancient solar wind could have imparted on an undifferentiated CV parent body is <3.5 nT, which is 3–4 and 3 orders of magnitude weaker than the paleointensities recorded by the CV chondrites Allende and Kaba, respectively. Therefore, the solar wind is highly unlikely to be the source of the NRM in CV chondrites. Nevertheless, future high sensitivity paleomagnetic studies of rapidly-cooled meteorites with high magnetic recording fidelity could potentially trace the evolution of the solar wind field in time. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109891
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, United States; Lowell Center for Space Science and Technology, University of Massachusetts, Lowell, MA 01854, United States
Recommended Citation:
Oran R.,Weiss B.P.,Cohen O.. Were chondrites magnetized by the early solar wind?[J]. Earth and Planetary Science Letters,2018-01-01,492