@article{Planetary:2000,
      recid = {2000},
      author = {Nie, Xike},
      title = {Iron Isotope Tracing of Planetary Surface Processes and  Rubidium Isotope Tracing of Volatile Element Depletion  Processes},
      publisher = {The University of Chicago},
      school = {Ph.D.},
      address = {2019-08},
      pages = {256},
      abstract = {Stable isotopes are very versatile and effective in  tracing geological and geochemical processes. This  dissertation uses stable Fe isotopes to trace Fe oxidation  and transport on planetary surfaces and uses stable Rb  isotopes to trace the depletion of moderately volatile  elements in planetary bodies. 

The iron UV photo-oxidation  process is studied by performing lab UV photo-oxidation  experiments and analyzing Fe isotopes in the lab-derived  samples and natural banded iron formation samples. It will  be demonstrated that this process is a highly possible Fe  oxidation mechanism to precipitate banded iron formations  and martian hematite spherules (also known as martian  “blueberries”). Hematite spherule samples collected in  Hawaii are an ideal terrestrial analogue of martian  hematite spherules. Here they are studied for their Fe  isotopes to investigate their detailed formation history,  providing insights into the formation of these enigmatic  martian hematite spherules (Chapter 2).

This dissertation  also presents a new Rb purification and isotope measurement  method that has been developed over the past three years.  Rubidium is a new isotopic tracer, and studies on Rb  isotopes are very limited due to the difficulty of these  measurements. The outlined procedure is capable of  achieving high-precision Rb isotopic analyses of even  Rb-depleted samples. By performing high-precision Rb  isotopic analyses of terrestrial, lunar, martian, and  chondrite samples, it will be shown that the depletion of  moderately volatile elements in the Moon is related to the  status of the protolunar disk after the Moon-forming giant  impact. The heavy Rb isotopic composition of the bulk Moon  relative to the Earth argues against models of partial  condensation as the cause for lunar volatile element  depletion. In contrast, a protolunar disk with a vapor  layer, which transports volatile elements towards the Earth  and is replenished by the underlying magma layer, can  quantitatively explain the moderately volatile element  depletion and isotope fractionation of the Moon (Chapter  3).},
      url = {http://knowledge.uchicago.edu/record/2000},
      doi = {https://doi.org/10.6082/uchicago.2000},
}