Geochemistry, Petrology, and Thermal Properties of Lava from Fissure 17 in the 2018 Kilauea Eruption

dc.contributor.advisorWhittington, Alan
dc.contributor.authorLira, Justice Joelle
dc.contributor.committeeMemberGodet, Alexis
dc.contributor.committeeMemberLambert, Lance
dc.creator.orcidhttps://orcid.org/0000-0002-3388-1938
dc.date.accessioned2024-02-12T14:54:22Z
dc.date.available2024-02-12T14:54:22Z
dc.date.issued2021
dc.descriptionThis item is available only to currently enrolled UTSA students, faculty or staff. To download, navigate to Log In in the top right-hand corner of this screen, then select Log in with my UTSA ID.
dc.description.abstractIn 2018, a complex lava erupted from Fissure 17 during the Lower East Rift Zone (LERZ) eruption of Kilauea, Hawaii. Fissure 17 was active from May 13-25 of 2018, and was more explosive than other vents, which produced fluid basalt. The Fissure 17 lavas plotted on a linear mixing trend between basalt and icelandite (iron-rich aluminum-poor andesite). Mixing of two different lavas is visible in hand specimen, with rigid crystalline inclusions in a microcrystalline groundmass that sheared around them. Our preliminary hypothesis was fresh basaltic lava encountering a cool crystal-rich evolved mush pocket from a previous magmatic episode; possibly a 1955 lava, creating icelandite inclusions in basalt. However, geochemical analyses indicate that the inclusions are basaltic and surrounded by andesitic lava. Fissure 17 lavas are consistent with the MELTS mixing model by Gansecki et al. (2019). Based on the petrography and thermal properties, a second source of basaltic material involved in mixing was added. This matches geochemically with the original (undifferentiated) 1955 lava. Calorimetry was used to determine the glass content of the icelandite groundmass (~50%) and the basaltic inclusions (undetectable). There is a possibility that inclusions could be xenoliths of 1955 lava. The conclusion is that, although in the field this lava is visibly hybridized, with numerous inclusions, these inclusions are not the major source of the geochemical variation in the suite. Instead of basalt containing andesitic inclusions, we have andesite / basaltic andesite containing basaltic xenoliths. The majority of the mixing occurred between two crystal-poor magmas, one already the product of mixing between two basaltic end-members and is now invisible. The broader implication is that visible evidence of mixing may tell a different story to the geochemical evidence in a single rift zone eruption.
dc.description.departmentGeosciences
dc.format.extent112 pages
dc.format.mimetypeapplication/pdf
dc.identifier.isbn9798759966982
dc.identifier.urihttps://hdl.handle.net/20.500.12588/4428
dc.languageen
dc.subjectVolcanology
dc.subjectIcelandite groundmass
dc.subjectRift zone eruption
dc.subject.classificationGeology
dc.subject.classificationGeophysics
dc.titleGeochemistry, Petrology, and Thermal Properties of Lava from Fissure 17 in the 2018 Kilauea Eruption
dc.typeThesis
dc.type.dcmiText
dcterms.accessRightspq_closed
thesis.degree.departmentGeosciences
thesis.degree.grantorUniversity of Texas at San Antonio
thesis.degree.levelMasters
thesis.degree.nameMaster of Science

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