DOI: 10.1016/j.epsl.2018.03.013
Scopus记录号: 2-s2.0-85043983076
论文题名: Fe isotope composition of bulk chondrules from Murchison (CM2): Constraints for parent body alteration, nebula processes and chondrule-matrix complementarity
作者: Hezel D.C. ; Wilden J.S. ; Becker D. ; Steinbach S. ; Wombacher F. ; Harak M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 490 起始页码: 31
结束页码: 39
语种: 英语
英文关键词: chondrule formation
; chondrules
; complementarity
; Fe isotopes
; matrix
; tomography
Scopus关键词: Iron
; Isotopes
; Matrix algebra
; Meteorites
; Population distribution
; Tomography
; Chondrule formations
; chondrules
; complementarity
; Compositional distribution
; Fe isotopes
; Isotope compositions
; Ordinary chondrites
; Primitive meteorites
; Iron compounds
; chondrule
; complementarity
; iron
; isotopic composition
; Murchison meteorite
; parent body
; tomography
英文摘要: Chondrules are a major constituent of primitive meteorites. The formation of chondrules is one of the most elusive problems in cosmochemistry. We use Fe isotope compositions of chondrules and bulk chondrites to constrain the conditions of chondrule formation. Iron isotope compositions of bulk chondrules are so far only known from few studies on CV and some ordinary chondrites. We studied 37 chondrules from the CM chondrite Murchison. This is particularly challenging, as CM chondrites contain the smallest chondrules of all chondrite groups, except for CH chondrites. Bulk chondrules have δ56Fe between −0.62 and +0.24‰ relative to the IRMM-014 standard. Bulk Murchison has as all chondrites a δ56Fe of 0.00‰ within error. The δ56Fe distribution of the Murchison chondrule population is continuous and close to normal. The width of the δ56Fe distribution is narrower than that of the Allende chondrule population. Opaque modal abundances in Murchison chondrules is in about 67% of the chondrules close to 0 vol.%, and in 33% typically up to 6.5 vol.%. Chondrule Al/Mg and Fe/Mg ratios are sub-chondritic, while bulk Murchison has chondritic ratios. We suggest that the variable bulk chondrule Fe isotope compositions were established during evaporation and recondensation prior to accretion in the Murchison parent body. This range in isotope composition was likely reduced during aqueous alteration on the parent body. Murchison has a chondritic Fe isotope composition and a number of chondritic element ratios. Chondrules, however, have variable Fe isotope compositions and chondrules and matrix have complementary Al/Mg and Fe/Mg ratios. In combination, this supports the idea that chondrules and matrix formed from a single reservoir and were then accreted in the parent body. The formation in a single region also explains the compositional distribution of the chondrule population in Murchison. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109939
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: University of Cologne, Department of Geology and Mineralogy, Zülpicher Str. 49b, Köln, 50674, Germany; Natural History Museum, Department of Mineralogy, Cromwell Road, London, SW7 5BD, United Kingdom; Steinmann-Institut, Poppelsdorfer Schloss, Meckenheimer Allee 169, Bonn, 53115, Germany; Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Materialphysik im Weltraum, Linder Höhe, Köln, 51147, Germany
Recommended Citation:
Hezel D.C.,Wilden J.S.,Becker D.,et al. Fe isotope composition of bulk chondrules from Murchison (CM2): Constraints for parent body alteration, nebula processes and chondrule-matrix complementarity[J]. Earth and Planetary Science Letters,2018-01-01,490