Universität zu Köln

Friend, Pia ORCID: 0000-0002-9042-3300, Hezel, Dominik C. and Mucerschi, Daniel (2016). The conditions of chondrule formation, Part II: Open system. Geochim. Cosmochim. Acta, 173. S. 198 - 210. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD. ISSN 1872-9533

Full text not available from this repository.

Abstract

We studied the texture of 256 chondrules in thin sections of 16 different carbonaceous (CV, CR, CO, CM, CH) and Rumuruti chondrites. In a conservative count similar to 75% of all chondrules are mineralogically zoned, i.e. these chondrules have an olivine core, surrounded by a low-Ca pyroxene rim. A realistic estimate pushes the fraction of zoned chondrules to >90% of all chondrules. Mineralogically zoned chondrules are the dominant and typical chondrule type in carbonaceous and Rumuruti chondrites. The formation of the mineralogical zonation represents a fundamentally important process of chondrule formation. The classic typification of chondrules into PO, POP and PP might in fact represent different sections through mineralogically zoned chondrules. On average, the low-Ca pyroxene rims occupy 30 vol.% of the entire chondrule. The low-Ca pyroxene most probably formed by reaction of an olivine rich chondrule with SiO from the surrounding gas. This reaction adds 3-15 wt.% of material, mainly SiO2, to the chondrule. Chondrules were open systems and interacted substantially with the surrounding gas. This is in agreement with many previous studies on chondrule formation. This open system behaviour and the exchange of material with the surrounding gas can explain bulk chondrule compositional variations in a single meteorite and supports the findings from complementarity that chondrules and matrix formed from the same chemical reservoir. (C) 2015 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Friend, Pia UNSPECIFIED orcid.org/0000-0002-9042-3300 UNSPECIFIED Hezel, Dominik C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Mucerschi, Daniel UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-287196
DOI:	10.1016/j.gca.2015.10.026
Journal or Publication Title:	Geochim. Cosmochim. Acta
Volume:	173
Page Range:	S. 198 - 210
Date:	2016
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Place of Publication:	OXFORD
ISSN:	1872-9533
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language SYNCHROTRON MICROTOMOGRAPHY; FERROMAGNESIAN CHONDRULES; CARBONACEOUS CHONDRITES; MAGNESIAN CHONDRULES; ORIGIN; CONDENSATION; CONSTRAINTS; COMPONENTS; MATRIX; AGES Multiple languages Geochemistry & Geophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/28719