Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664277
Title: A geochemical investigation of differentiation in the early solar system
Author: McDermott , Kathryn Helen
Awarding Body: Open University
Current Institution: Open University
Date of Award: 2013
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Abstract:
Iron meteorites, believed to represent the cores of differentiated planetary bodies (Kliene et al., 2005), have been found to predate the most primitive bodies, the chondrites, by forming 1-2 Ma after calcium-aluminum inclusions (CAI) formation compared to the 1-5 Ma after CAI age range of the chondrites (Kleine et al., 2008). This raised questions about the composition of the early formed planetary bodies and the thermal processes that produced the iron meteorite within a 1-2 Ma time interval. Four iron meteorite groups contain numerous silicate inclusions; the study of such inclusions can provide details about the parent body composition and the thermal histories of the whole planetary body that produced these silicate-bearing iron meteorite groups. This thesis undertook major element, trace element and oxygen isotopic analysis of a selection of the silicate inclusions located within silicate-bearing liE and lAB iron meteorites. The liE silicate inclusions show a range in silicate compositions, and oxygen isotope ratios which shows similarities with the H chondrite meteorites implying that these meteorite groups originate from a common parent body. The silicate materials located within the lABs are homogeneously chondritic in composition, and have an oxygen isotopic composition similar to the winonaite meteorite group. The formation theory for both silicate-bearing iron meteorite groups includes arrested planetary silicate-metal differentiation followed by an impact into the parent body that locally mixed silicate, metallic and sulphide material. Variations in the composition of the silicate inclusions lead to variation between the two formation theories with the liE parent body requiring a more complex thermal history to account for the range of inclusion compositions. The results from this work provide detailed insight into the formation and initial parent body composition of the silicate-bearing iron meteorites and the differentiation processes occurring in the early Solar System.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.664277  DOI: Not available
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