Select problems in planetary structural Geology: Global-scale tectonics on Io, regional-scale kinematics on Venus, and local-scale field analyses on Earth with application to Mars

Persistent Link:
http://hdl.handle.net/10150/280768
Title:
Select problems in planetary structural Geology: Global-scale tectonics on Io, regional-scale kinematics on Venus, and local-scale field analyses on Earth with application to Mars
Author:
Jaeger, Windy Lee
Issue Date:
2005
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Io's mountains are cataloged in order to investigate their formation. Of the 101 mountains imaged with sufficient coverage and resolution for further analysis, 4 are volcanoes, and 97 are tectonic massifs. Of the 97 tectonic mountains, ≥40 abut paterae (volcanic or volcano-tectonic depressions). This juxtaposition is unlikely to be coincidental as the probability of it occurring by chance is ∼1.08%. The observed mountain-patera association may be due to orogenic faults acting as conduits for magma ascent, thus fueling patera formation near mountains. As resurfacing buries a shell of material from Io's surface to the base of the lithosphere, its effective radius is reduced and it heats up. The volume change due to subsidence and thermal expansion is calculated as a function of lithospheric thickness. Conservation of volume dictates that this material is uplifted at Io's surface. By estimating the total volume of mountains, Io's average lithospheric thickness is constrained to ≥12 km. A kinematic analysis of Nefertiti Corona, Venus, reveals that the corona's interior moved east as a relatively coherent thrust sheet with most deformation occurring on the distal margin. Additionally, an en-echelon array indicates a history of semi-brittle deformation on the northern side of Nefertiti's tectonic annulus. Regional heating from the thermal diapir that formed Nefertiti probably reduced the crustal viscosity and enabled the semi-brittle deformation. The "Odessa Craters" in the Channeled Scabland of eastern Washington State are basaltic ring structures (BRSs) 50-500 m in diameter that are comprised of discontinuous, concentric outcrops of subvertically-jointed basalt and autointrusive basaltic dikes. It is postulated that they formed as follows: phreatovolcanic activity disrupted a relatively thin, active lava flow forming rootless cones; the lava flow inflated around the cones; tensile stresses caused concentric fracturing; dikes exploited the fractures and fed lava to the surface; and subsequent erosive floods excavated the structures. A second population of BRSs near Tokio Station, WA, are morphologically analogous to quasi-circular structures in Athabasca Valles, Mars (a region that is geologically similar to the Channeled Scabland). If the martian features formed as BRSs, then they indicate local water-lava interactions and at least two floods through Athabasca Valles.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Geology.; Physics, Astronomy and Astrophysics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Planetary Sciences
Degree Grantor:
University of Arizona
Advisor:
Baker, Victor R.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleSelect problems in planetary structural Geology: Global-scale tectonics on Io, regional-scale kinematics on Venus, and local-scale field analyses on Earth with application to Marsen_US
dc.creatorJaeger, Windy Leeen_US
dc.contributor.authorJaeger, Windy Leeen_US
dc.date.issued2005en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractIo's mountains are cataloged in order to investigate their formation. Of the 101 mountains imaged with sufficient coverage and resolution for further analysis, 4 are volcanoes, and 97 are tectonic massifs. Of the 97 tectonic mountains, ≥40 abut paterae (volcanic or volcano-tectonic depressions). This juxtaposition is unlikely to be coincidental as the probability of it occurring by chance is ∼1.08%. The observed mountain-patera association may be due to orogenic faults acting as conduits for magma ascent, thus fueling patera formation near mountains. As resurfacing buries a shell of material from Io's surface to the base of the lithosphere, its effective radius is reduced and it heats up. The volume change due to subsidence and thermal expansion is calculated as a function of lithospheric thickness. Conservation of volume dictates that this material is uplifted at Io's surface. By estimating the total volume of mountains, Io's average lithospheric thickness is constrained to ≥12 km. A kinematic analysis of Nefertiti Corona, Venus, reveals that the corona's interior moved east as a relatively coherent thrust sheet with most deformation occurring on the distal margin. Additionally, an en-echelon array indicates a history of semi-brittle deformation on the northern side of Nefertiti's tectonic annulus. Regional heating from the thermal diapir that formed Nefertiti probably reduced the crustal viscosity and enabled the semi-brittle deformation. The "Odessa Craters" in the Channeled Scabland of eastern Washington State are basaltic ring structures (BRSs) 50-500 m in diameter that are comprised of discontinuous, concentric outcrops of subvertically-jointed basalt and autointrusive basaltic dikes. It is postulated that they formed as follows: phreatovolcanic activity disrupted a relatively thin, active lava flow forming rootless cones; the lava flow inflated around the cones; tensile stresses caused concentric fracturing; dikes exploited the fractures and fed lava to the surface; and subsequent erosive floods excavated the structures. A second population of BRSs near Tokio Station, WA, are morphologically analogous to quasi-circular structures in Athabasca Valles, Mars (a region that is geologically similar to the Channeled Scabland). If the martian features formed as BRSs, then they indicate local water-lava interactions and at least two floods through Athabasca Valles.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectGeology.en_US
dc.subjectPhysics, Astronomy and Astrophysics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplinePlanetary Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBaker, Victor R.en_US
dc.identifier.proquest3158212en_US
dc.identifier.bibrecord.b4813742xen_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.