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dc.contributor.authorCraft, Kathleen Lianaen_US
dc.date.accessioned2015-05-02T06:00:11Z
dc.date.available2015-05-02T06:00:11Z
dc.date.issued2013-11-07en_US
dc.identifier.othervt_gsexam:1655en_US
dc.identifier.urihttp://hdl.handle.net/10919/51959
dc.description.abstractEvidence of hydrothermal and tectonic activity is found throughout our solar system. Here I investigated hydrothermal and fracturing processes on three planetary bodies: Earth, Mars and Europa. For the first project, we set up a dike-driven hydrothermal system and calculated heat and water flow using boundary layer theory. Water flow rates and volumes were then compared to the requirements for surface feature formation. Results found that the water volumes produced were adequate to form Athabasca Valles, except the flow rates were low. Episodic flood releases could enable the higher flow rates if water was first collected in aquifers, possibly stored beneath ice. On the icy moon Europa, I modeled a proposed sill emplacement mechanism using a finite element code and found that water could flow up through an approximately 10 km thick ice shell without freezing. The analysis also found that shallow cracks in the ice combined with deep cracks cause a stress direction change that helps the fracture turn and propagate more horizontally. However, the sill lifetime is less than the time a study by Dombard et al. [2013] calculated to be necessary for the formation of flexure fractures along margins of double ridges. Replenishment processes will be explored in future work to help extend sill lifetime. The last investigation calculated dike induced permeability changes in the crust on Earth and Mars and related the changes to water and heat flow rates and water volumes. Comparisons were made to event plume heat and elevated fluid temperatures observed at mid-ocean ridges. Heat values determined by the models agreed well with the 10^14 to 10^17 J expected. For the Martian model, water flow rates and volumes were compared to formation requirements for the valley system Athabasca Valles. Results found that flow rates would be adequate in the high permeability damage zone adjacent to the dike. However, the lowered permeability outside the damage zone would restrict replenishment flow and could cause the need for water storage and periodic release between flood events as the volume within the damage zone is not adequate for the valley formation.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjecthydrothermalen_US
dc.subjectdikeen_US
dc.subjectsillen_US
dc.subjecticeen_US
dc.subjectMarsen_US
dc.subjectEuropaen_US
dc.subjectAthabasca Vallesen_US
dc.subjectfractureen_US
dc.titleDike-Driven Hydrothermal Processes on Mars and Sill Emplacement on Europaen_US
dc.typeDissertationen_US
dc.contributor.departmentGeosciencesen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineGeosciencesen_US
dc.contributor.committeechairLowell, Robert P.en_US
dc.contributor.committeememberKing, Scott Daviden_US
dc.contributor.committeememberPatterson, Gerald Wesleyen_US
dc.contributor.committeememberRimstidt, James Donalden_US
dc.contributor.committeememberKraal, Erin R.en_US


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