(210 Pb/ 226 Ra) variations during the 1994-2001 intracaldera volcanism at Rabaul Caldera

dc.contributor.authorCunningham, H. S.
dc.contributor.authorTurner, S. P.
dc.contributor.authorPatia, H.
dc.contributor.authorWysoczanski, R.
dc.contributor.authorNichols, R.
dc.contributor.authorEggins, Stephen
dc.contributor.authorDosseto, A.
dc.date.accessioned2015-12-10T22:16:18Z
dc.date.issued2009
dc.date.updated2016-02-24T10:32:10Z
dc.description.abstractDetermining the timing and source of gas transfer during intermittent intracaldera volcanism can aid in our understanding of degassing in these large systems. Using (210Pb/226Ra) ratios, (parentheses denote activity ratios) as a time-sensitive tracer, injections of 222Rn and the subsequent time scales of gas accumulation and loss can be determined. Variations in (210Pb/226Ra) have been measured for 15 volcanic products erupted at Rabaul Caldera over the period 1994 to 2001. In addition, one basaltic enclave from the 1937 eruption was also analyzed. Water and carbon dioxide contents determined from olivine hosted melt inclusions erupted in 1997 are < 1% and suggest extensive shallow-level degassing. Both 210Pb excesses and deficits are found in andesites and dacites, whereas the basaltic enclave displays an (210Pb/226Ra)0 ratio of 7. Between 1994 and 1997 three samples with (210Pb/226Ra) deficits were erupted which indicate open system gas loss since 1992 and 1994. No correlation exists between (210Pb/226Ra) and lava chemistry, eruptive style or date. 210Pb excesses are more common than deficits in Rabaul samples but cannot be explained by plagioclase feldspar accumulation, Pb sublimate accumulation or differentiation. Instead, a model of intra-magma 222Rn transfer can produce 210Pb excesses of the appropriate magnitude if gas transfer occurs over 1-5 years from an underlying body of magma that is 2-10 times larger than the volume of erupted material and that is consistent with geophysical estimates. Although intermittent gas transfer events can be inferred by the development of 210Pb excess, there is no evidence at Rabaul for a direct link between eruptive style, gas flux and (210Pb/226Ra).
dc.identifier.issn0377-0273
dc.identifier.urihttp://hdl.handle.net/1885/50870
dc.publisherElsevier
dc.sourceJournal of Volcanology and Geothermal Research
dc.subject(210 Pb/ 226 Ra)
dc.subjectgas transfer
dc.subjectRabaul Caldera
dc.subjecttimescales
dc.subjectU-series
dc.subjectvolatiles
dc.subjectCarbon dioxide
dc.subjectDegassing
dc.subjectFeldspar
dc.subjectFragrances
dc.subjectGases
dc.subjectLead
dc.subjectLead alloys
dc.subjectOlivine
dc.subjectOpen systems
dc.subjectSilicate minerals
dc.subjectRadon
dc.subjectaccumulation rate
dc.subjectandesite
dc.subjectca (210Pb/226Ra)
dc.subjectgas transfer
dc.subjectRabaul Caldera
dc.subjecttimescales
dc.subjectU-series
dc.subjectvolatiles
dc.title(210 Pb/ 226 Ra) variations during the 1994-2001 intracaldera volcanism at Rabaul Caldera
dc.typeJournal article
local.bibliographicCitation.issue3-4
local.bibliographicCitation.lastpage426
local.bibliographicCitation.startpage416
local.contributor.affiliationCunningham, H.S., Macquarie University
local.contributor.affiliationTurner, S P, Macquarie University
local.contributor.affiliationPatia, H, Rabaul Volcano Observatory
local.contributor.affiliationWysoczanski, R., Japan Agency for Marine Earth Science and Technology
local.contributor.affiliationNichols, R., Japan Agency for Marine Earth Science and Technology
local.contributor.affiliationEggins, Stephen, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationDosseto, A, Macquarie University
local.contributor.authoremailu9109238@anu.edu.au
local.contributor.authoruidEggins, Stephen, u9109238
local.description.embargo2037-12-31
local.description.notesImported from ARIES
local.identifier.absfor040304 - Igneous and Metamorphic Petrology
local.identifier.absfor040314 - Volcanology
local.identifier.ariespublicationu4047674xPUB212
local.identifier.citationvolume184
local.identifier.doi10.1016/j.jvolgeores.2009.04.018
local.identifier.scopusID2-s2.0-67649502876
local.identifier.thomsonID000268522100015
local.identifier.uidSubmittedByu4047674
local.type.statusPublished Version

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