Host-rock deformation around magmatic dikes : integrating field observations and mechanical models
Abstract/Contents
- Abstract
- Dikes are the dominant form of magma transport within the earth's shallow crust. At basaltic volcanoes, dikes commonly initiate at a central magma reservoir and propagate laterally for distances that are much greater than their heights. Because vertical propagation is more limited, most dike intrusions fail to reach the surface (Klein, 1982; White et al., 2006). Dikes that do intersect the surface feed eruptions through fissures, or linear volcanic vents. Fissure eruptions tend to be relatively short-lived (hours, days) because magma flow through sheet-like conduits is thermally unfavorable (Delaney and Pollard, 1982). However, flow in fissures commonly localizes into discrete vents that eventually form a cylindrical-shaped conduit known as a volcanic plug, at which point the eruption can sustain significantly greater volumetric flow rates and can persist for longer periods of time (months, years) (e.g. Richter et al., 1970). Therefore, in order to assess the volcanic hazard of a dike intrusion event, it becomes necessary to know first whether the dike will propagate to the surface and initiate an eruption, and then whether the fissure eruption will be short-lived or sustained through a larger conduit. The physical processes that govern dike propagation to the surface and the transition of fissures into volcanic plugs all involve deformation of the surrounding rocks that host the dike or fissure. This dissertation integrates geologic observations with physics-based models to gain new insight about deformation and the state of stress in host rocks as they relate to dike propagation and the evolution of conduit geometry.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2017 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Townsend, Meredith Rose |
|---|---|
| Associated with | Stanford University, Department of Geological Sciences. |
| Primary advisor | Hilley, George E |
| Primary advisor | Pollard, David D |
| Thesis advisor | Hilley, George E |
| Thesis advisor | Pollard, David D |
| Thesis advisor | Segall, Paul, 1954- |
| Advisor | Segall, Paul, 1954- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Meredith Rose Townsend. |
|---|---|
| Note | Submitted to the Department of Geological Sciences. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2017. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2017 by Meredith Rose Townsend
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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