Earth and Planetary Sciences ETDs

Publication Date

8-27-2012

Abstract

Constraints were placed on the density of kimberlitic melts containing varying amounts of CO2 using high pressure sink/float experiments. The melt composition used was carefully selected and was prepared free of H2O and minor elements in order to focus on the effect of CO2. Experiments were run in graphite capsules over a pressure range of 4-10 GPa in a multi-anvil apparatus using Fo100 and Fo90 spheres as density markers. The compositions used contained 0, 3, 6, and 12 wt% CO2 and were derived from mixing the 0 and 12 wt% CO2 compositions together. Run products were analyzed with FTIR to confirm the presence of carbonate and lack of water and with EPMA to verify the composition. Carbon was quantified using the by difference method, but plans are in place to develop a method to quantify this element by EPMA. The density data places constraints on the location of the melt compression curves, and shows the melts to be eruptible from pressures below 9 GPa (10 GPa for the 6 wt% CO2 composition) on Earth. This data is also applicable to Venus, and all compositions are eruptible from up to 9 GPa according to current Venus mantle density models.

Degree Name

Earth and Planetary Sciences

Level of Degree

Masters

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

McCubbin, Francis M.

Second Committee Member

Fischer, Tobias P.

Language

English

Keywords

CO2, melt density, kimberlite, experimental petrology

Document Type

Thesis

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