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dc.contributor.authorSlater-Reynolds, V.
dc.contributor.authorMcSween, H. Y.
dc.date.accessioned2021-02-12T21:17:26Z
dc.date.available2021-02-12T21:17:26Z
dc.date.issued2005-01-01
dc.identifier.citationSlater-Reynolds, V., & McSween, H. Y. (2005). Peak metamorphic temperatures in type 6 ordinary chondrites: An evaluation of pyroxene and plagioclase geothermometry. Meteoritics & Planetary Science, 40(5), 745-754.
dc.identifier.issn1945-5100
dc.identifier.doi10.1111/j.1945-5100.2005.tb00977.x
dc.identifier.urihttp://hdl.handle.net/10150/656000
dc.description.abstractQuantifying the peak temperatures achieved during metamorphism is critical for understanding the thermal histories of ordinary chondrite parent bodies. Various geothermometers have been used to estimate equilibration temperatures for chondrites of the highest metamorphic grade (type 6), but results are inconsistent and span hundreds of degrees. Because different geothermometers and calibration models were used with different meteorites, it is unclear whether variations in peak temperatures represent actual ranges of metamorphic conditions within type 6 chondrites or differences in model calibrations. We addressed this problem by performing twopyroxene geothermometry, using QUILF95, on the same type 6 chondrites for which peak temperatures were estimated using the plagioclase geothermometer (Nakamuta and Motomura 1999). We also calculated temperatures for published pyroxene analyses from other type 6 H, L, and LL chondrites to determine the most representative peak metamorphic temperatures for ordinary chondrites. Pyroxenes record a narrow, overlapping range of temperatures in H6 (865-926 degrees C), L6 (812-934 degrees C), and LL6 (874-945 degrees C) chondrites. Plagioclase temperature estimates are 96-179 degrees C lower than pyroxenes in the same type 6 meteorites. Plagioclase estimates may not reflect peak metamorphic temperatures because chondrule glass probably recrystallized to plagioclase prior to reaching the metamorphic peak. The average temperature for H, L, and LL chondrites (~900 degrees C), which agrees with previously published oxygen isotope geothermometry, is at least 50 degrees C lower than the peak temperatures used in current asteroid thermal evolution models. This difference may require minor adjustments to thermal model calculations.
dc.language.isoen
dc.publisherThe Meteoritical Society
dc.relation.urlhttps://meteoritical.org/
dc.rightsCopyright © The Meteoritical Society
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectGeothermometry
dc.subjectchondrites
dc.subjectplagioclase
dc.subjectpyroxenes
dc.titlePeak metamorphic temperatures in type 6 ordinary chondrites: An evaluation of pyroxene and plagioclase geothermometry
dc.typeArticle
dc.typetext
dc.identifier.journalMeteoritics & Planetary Science
dc.description.collectioninformationThe Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.
dc.eprint.versionFinal published version
dc.description.admin-noteMigrated from OJS platform February 2021
dc.source.volume40
dc.source.issue5
dc.source.beginpage745
dc.source.endpage754
refterms.dateFOA2021-02-12T21:17:26Z


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