Elastic properties of mantle minerals by multiple methods and at high pressures and temperatures

Discerning how the sound velocities of minerals vary with pressure, temperature, and composition is critical to understanding the physical state and mineral makeup of the Earth’s mantle. Despite the impact of mantle composition on a wide range of problems in the geosciences, large uncertainties remain, both for the upper and lower mantle. This is primarily due to the challenges of both extrapolating laboratory measurements at ambient conditions to the pressure and temperature conditions of the deep earth and of making such measurements directly under those conditions. My research aim has been to extend measurements of sound speed in minerals to the high P,T conditions of the deep Earth. Firstly, I explore compositional elasticity trends among clinopyroxenes by measuring the sound velocities of an Fe-rich augite at room conditions. Secondly, I measure the elastic properties of natural garnets, both as a function of composition and of pressure, using two complementary techniques. I then present measurements made under simultaneous mantle P,T conditions for a near-endmember garnet composition. Finally, I transform this sample to the primary lower mantle mineral, bridgmanite, and determine its high- pressure elastic properties in order to better understand the effect of Al-incorporation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Geology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Ginsberg, Paul

Contributors dc:contributor

• Bass, Jay D
• Alp, Ercan E
• Lundstrom, Craig C
• Liu, Lijun

• Augite
• Mineral Physics
• Sound Velocities
• Brillouin Scattering
• Diamond Anvil Cell
• Laser Heating
• Garnet
• Bridgmanite

Statement dc:rights

• Copyright 2023 Paul A Ginsberg

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/121213

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F121213