Show simple item record

dc.contributor.advisorBergantz, George
dc.contributor.authorSchleicher, Jillian
dc.date.accessioned2017-10-26T20:44:13Z
dc.date.available2017-10-26T20:44:13Z
dc.date.submitted2017-08
dc.identifier.otherSchleicher_washington_0250E_17771.pdf
dc.identifier.urihttp://hdl.handle.net/1773/40392
dc.descriptionThesis (Ph.D.)--University of Washington, 2017-08
dc.description.abstractMagmatic systems present an apparent paradox: they exist as long-term, crystal-rich magmas (called mushes) which are mechanically locked, yet crystals in exposed plutons and volcanic deposits with diverse histories indicate magmatic mobilization and mixing processes are common. Geochemical and petrologic analyses of igneous rocks and crystals provide a way to distinguish magmatic events such as intrusion, crystallization, assimilation, and mixing that occurred. These events cannot be directly observed, so previous studies have used experiments and numerical simulations to investigate the dynamics of mobilization and mixing. The high- crystal fractions in mushes require consideration of particle-particle-liquid interactions, which previous continuum and quasi-multiphase models do not recover. This dissertation takes a multi-scale approach to understanding the processes of mush mobilization and mixing. Chapters 2 and 3 present a discrete element method-computational fluid dynamics (DEM-CFD) model of a basalt and olivine magmatic mush subject to intrusion by basaltic magma from below. Chapter 2 demonstrates the crystal-scale control on the system-wide response to the intrusion. The localized mobilization of crystals above the intrusion site produces a region called the mixing bowl, where liquids and crystals are fluidized and mixed. Monitoring the crystals and liquid throughout the intrusion demonstrates the potential for diverse crystal populations to be created in even simple magmatic systems. Chapter 3 quantifies the dispersion of crystals in the simulations from their initial state for a range of intrusion velocities. The crystal dispersion occurs with an exponential relationship with time, and a mixing time scaling produces a single curve for the tested intrusion rates. Extrapolating the results to a realistic magmatic system produces mixing times that agree with those inferred for mixing events occurring in nature. Chapter 4 is a case study of a natural mush, the 1868 picrite eruption of Mauna Loa, Hawaii. Geochemical analyses at the crystal-scale demonstrate the existence of six olivine populations. These populations reflect a diversity of magmatic conditions and processes within the central and rift magmatic systems in Mauna Loa. Also included with this dissertation are three supplementary movies. These movies show the simulation presented in Chapters 2 and 3. Movie 2.1 shows the intrusion of the magma into the mush, Movie 2.2 shows the coordination number of the crystals within the mush, and Movie 2.3 tracks the three pairs of crystals described in the text.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.relation.haspartMovie2_1.avi; video; Movie 2.1: movie of Figure 2.2, showing the simulation of the open-system intrusion into the crystal-rich mush. The left shows the crystals and liquids, and the right shows the corresponding crystal volume fraction..
dc.relation.haspartMovie2_2.avi; video; Movie 2.2: The same simulated intrusion as Movie 2.1, but the crystals are colored based on their coordination number. Values range from one, representing crystals touching only one other crystal, to six where crystals are in hexagonal packing. Figure 2.4.
dc.relation.haspartMovie2_3.avi; video; Movie 2.3: The same simulation as Movies 2.1 and 2.2, highlighting the crystals monitored in Figures 2.5 and 2.6. The three pairs of crystals have been shown with the same colors in these figures, but are 2.5 times larger than their actual size to increas.
dc.rightsnone
dc.subjectCrystal-rich magma
dc.subjectEarth Sciences
dc.subjectFluidization
dc.subjectMagma mixing
dc.subjectPicrite
dc.subjectGeology
dc.subject.otherEarth and space sciences
dc.titleCrystal-scale control on magmatic mush mobilization and mixing
dc.typeThesis
dc.embargo.termsOpen Access


Files in this item

Thumbnail
Thumbnail
Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record