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dc.contributor.authorMaclennan, John  Concept link
dc.date.accessioned2017-04-11T18:22:17Z
dc.date.available2017-08-16T08:42:22Z
dc.date.issued2017-02-16
dc.identifier.citationGeochemistry, Geophysics, Geosystems 18 (2017): 597–616en_US
dc.identifier.urihttps://hdl.handle.net/1912/8887
dc.descriptionAuthor Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 18 (2017): 597–616, doi:10.1002/2016GC006633.en_US
dc.description.abstractThe CO2 contents of olivine-hosted melt inclusions have previously been used to constrain the depth of magma chambers in basaltic systems. However, the vast majority of inclusions have CO2 contents which imply entrapment pressures that are significantly lower than those obtained from independent petrological barometers. Furthermore, a global database of melt inclusion compositions from low inline image settings, indicates that the distribution of saturation pressures varies surprisingly little between mid-ocean ridges, ocean islands, and continental rift zones. 95% of the inclusions in the database have saturation pressures of 200 MPa or less, indicating that melt inclusion CO2 does not generally provide an accurate estimate of magma chamber depths. A model of the P-V-T-X evolution of olivine-hosted melt inclusions was developed so that the properties of the inclusion system could be tracked as the hosts follow a model P-T path. The models indicate that the principal control on the saturation of CO2 in the inclusion and the formation of vapor bubbles is the effect of postentrapment crystallization on the major element composition of the inclusions and how this translates into variation in CO2 solubility. The pressure difference between external melt and the inclusion is likely to be sufficiently high to cause decrepitation of inclusions in most settings. Decrepitation can account for the apparent mismatch between CO2-based barometry and other petrological barometers, and can also account for the observed global distribution of saturation pressures. Only when substantial postentrapment crystallization occurs can reconstructed inclusion compositions provide an accurate estimate of magma chamber depth.en_US
dc.description.sponsorshipNatural Environment Research Council Grant Number: (NE/I012508/1)en_US
dc.language.isoen_USen_US
dc.publisherJohn Wiley & Sonsen_US
dc.relation.urihttps://doi.org/10.1002/2016GC006633
dc.subjectMelt inclusionsen_US
dc.subjectOlivineen_US
dc.subjectCarbon dioxideen_US
dc.subjectMagma chamberen_US
dc.subjectBasalten_US
dc.titleBubble formation and decrepitation control the CO2 content of olivine-hosted melt inclusionsen_US
dc.typeArticleen_US
dc.description.embargo2017-08-16en_US
dc.identifier.doi10.1002/2016GC006633


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