Earth and Planetary Sciences ETDs

Publication Date

Fall 11-15-2018


Initial triple oxygen isotope analyses of lunar samples showed them to be indistinguishable from Earth, which led to numerous papers aimed at explaining the similarities. Recent high-precision analyses suggested either a subtle enrichment in Δ'17O or virtually no difference between the Earth and Moon. Herein we expand on previous studies by correlating the triple oxygen isotope measurements with different lunar lithologies. We show that these data can be explained by mixing between a light vapor phase, generated during the Giant Impact, and the residual material from the proto-lunar impactor ‘Theia’. There is a general decrease in Δ'17O with the expected contribution from the “contaminating” vapor phase. Our data suggests that the sample which best preserves the lunar mantle has a Δ'17O value of ‑0.030‰, giving us a minimum estimate for the lunar interior and the impactor Theia. The estimated Earth mantle value measured by this study is ‑0.052‰, suggesting a distinct difference between Earth and Moon.

Degree Name

Earth and Planetary Sciences

Level of Degree


Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Zachary Sharp

Second Committee Member

Charles Shearer

Third Committee Member

Jin Zhang




triple oxygen isotopes, isotopes, oxygen, moon, lunar, Giant Impact, Theia

Document Type


Included in

Geology Commons