About

Edwin Schauble is a professor of geochemistry and astrobiology in the Department of Earth, Planetary and Space Sciences at UCLA. His research group focuses on studying the chemical properties of natural materials at the atomic level. The primary goal of their work is to develop new chemical measurements that can be used to investigate both modern and ancient environments on Earth as well as other planets. Current research projects in his group include predicting how the stable-isotope compositions of various elements are influenced by common chemical reactions such as partial oxidation, and studying the abundances of isotopically substituted methane molecules in the atmosphere. These investigations require a detailed understanding of the molecular vibrational frequencies of molecules and crystals. Additionally, the group has created a number of animated molecular vibrations based on their research, which have been made available in a web-accessible archive.

Research topics

• Chemistry
• Physics
• Geology
• Nuclear physics
• Chromatography
• Geochemistry

Selected publications

• The evolution of methane clumped isotope compositions during nitrite-dependent anaerobic methane oxidation

  2025-01-01

  article
  PublisherDOI

• Cerium and europium isotope signatures of igneous differentiation

  2025-01-01

  article1st authorCorresponding
  PublisherDOI

• Nuclear volume and mass dependent fractionation of cerium isotopes

  GEOCHEMICAL JOURNAL · 2024-01-01 · 10 citations

  articleOpen access1st authorCorresponding

  Equilibrium cerium isotope fractionations in cerium-bearing minerals and aqueous species are estimated using electronic structure calculations that include both nuclear volume and mass dependent effects. As with europium and uranium, the nuclear volume effect in redox reactions goes in the opposite direction from equilibrium mass-dependent fractionation for 142Ce/140Ce because of the larger nuclear charge radius of the 142Ce nucleus. Mass-dependent effects dominate 136Ce/140Ce and 138Ce/140Ce fractionations because 136Ce, 138Ce, and 140Ce share very similar nuclear charge radii. 142Ce/140Ce is predicted to be lower in most Ce(IV)-bearing species than in coexisting Ce(III)-bearing species, particularly at high temperatures. However, species with Ce:Zr substitution, such as zirconium-rich compositions along the stetindite-zircon (CeSiO4-ZrSiO4) solid solution series and a model Ce-subsituted baddeleyite (CeZr3O8), may show higher 142Ce/140Ce at ambient to low-T metamorphic temperatures because of higher effective force constants acting on the smaller, more snug substitution sites. Ce(III)P(V) charge-coupled substitution into zircon is likewise associated with high 142Ce/140Ce relative to other Ce(III) species. 136Ce/140Ce and 138Ce/140Ce fractionations will tend to favor more massive isotopes in Ce(IV)-bearing species, by 0.1–1.0‰ at 25°C and 0.01–0.1‰ at 727°C depending on the species present. The models predict ~0.3‰ higher 142Ce/140Ce in Ce(III)-bearing solution than coexisting Ce(IV)-solids at ambient temperatures, roughly agreeing with measurements. Zircon in equilibrium with typical silicate melts is predicted to be slightly enriched in 140Ce relative to 142Ce, 138Ce, and 136Ce. Supplementary calculations based on 141Pr-Mössbauer spectroscopy literature suggest somewhat (~1/3) smaller nuclear volume fractionation effects than the electronic structure models.

  PublisherOA PDFDOI

• Equilibrium europium isotope fractionation in igneous and metamorphic systems

  2023-01-01

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Calcium isotope fractionation during melt immiscibility and carbonatite petrogenesis

  Geochemical Perspectives Letters · 2023 · 17 citations

  • Geochemistry
  • Geology
  • Chemistry

  Stable calcium isotopes have been used to suggest that subducted marine carbonates are frequently involved in the formation of carbonatites. Significant Ca isotope fractionations during carbonatite petrogenesis, however, could lead to a dramatically different picture. We present Ca isotope data for (i) coexisting (immiscible) carbonatite and silicate melts from high temperature centrifuging piston cylinder experiments, (ii) primary apatite and calcite/dolomite from natural carbonatites, and (iii) ab initio estimates for equilibrium Ca isotope partitioning in calcite, dolomite, and ankerite. Carbonatitic melts have lower δ⁴⁴Ca than their conjugate silicate melts, with an equilibrium fractionation factor [1000lnα(1000K)] of −0.21 ± 0.06 (tSE). We develop a quantitative four stage model for carbonatite petrogenesis (partial melting followed by fractional crystallisation, carbonatite-silicate melt immiscibility, and calcite/apatite accumulation) that fully explains our natural data (average δ⁴⁴CaBSE of −0.30 ± 0.03 ‰) and those from recent studies, without requiring isotopic contributions from recycled marine carbonates. Our results suggest that lighter isotopes of similarly bound cations (e.g., Mg, Fe, Sr, Ba, Zn) should be preferentially incorporated into carbonatitic melts and that calciocarbonatite formation involves melt immiscibility after differentiation of mantle-derived alkaline CO₂-bearing silicate melts.

  PublisherOA PDFDOI

• Iron isotope evidence of an impact origin for main-group pallasites

  Goldschmidt Abstracts · 2023

  • Nuclear physics
  • Chemistry
  • Physics
  PublisherOA PDFDOI

• Nuclear volume isotope fractionation of europium and other lanthanide elements

  GEOCHEMICAL JOURNAL · 2023 · 17 citations

  1st authorCorresponding
  • Chemistry
  • Geology
  • Chromatography

  The nuclear volume component of equilibrium field shift isotope fractionations in europium and other lanthanide elements is estimated using Mössbauer spectroscopy and electronic structure calculations. This effect goes in the opposite direction from equilibrium mass-dependent fractionation, and in the case of europium is predicted to dominate over mass dependent fractionation for most materials. Including both effects, Eu2+-bearing species will have approximately 0.4-1‰ higher 153Eu/151Eu than Eu3+-bearing species at 25ºC (298 K), and about 0.3‰ higher 153Eu/151Eu at 700ºC (973 K). Field shift fractionation mainly depends on oxidation state; differences in coordination structure without changes in oxidation state appear to have much weaker associated fractionations. Nuclear volume isotope fractionation will become even more dominant over mass dependent fractionation at higher temperatures because nuclear volume effects scale with 1/T (K), vs. 1/T2 for mass-dependent fractionation. Fractionation favoring high 153Eu/151Eu in minerals that preferentially incorporate Eu2+, such as plagioclase, is consistent with recent measurements on igneous rocks showing low 153Eu/151Eu in samples with large negative europium anomalies (Lee and Tanaka, 2021). The present results agree with the recent conclusion that equilibrium fractionation cannot explain cosmochemical REE fractionations in primitive meteoritical materials (Hu et al., 2021), because the net fractionation is too small (~0.2‰ or less) at temperatures >1200 K where vapor-phase REE species are relevant.

  PublisherOA PDFDOI

• First Principles Estimates of 238U/235U Fractionation in Solutions and Crystals

  AGU Fall Meeting Abstracts · 2020-12-01

  articleSenior author
  Publisher

• 4. Mass Dependence of Equilibrium Oxygen Isotope Fractionation in Carbonate, Nitrate, Oxide, Perchlorate, Phosphate, Silicate, and Sulfate Minerals

  2019-12-31 · 1 citations

  book-chapter1st authorCorresponding

  4. Mass Dependence of Equilibrium Oxygen Isotope Fractionation in Carbonate, Nitrate, Oxide, Perchlorate, Phosphate, Silicate, and Sulfate Minerals was published in Triple Oxygen Isotope Geochemistry on page 137.

  PublisherDOI

• Theoretical study of the 238 U/ 235 U fractionation in natural systems

  AGU Fall Meeting Abstracts · 2018-12-01

  articleSenior author
  Publisher

Recent grants

• Theoretical study of 238Uranium/235Uranium fractionation in nature

  NSF · $250k · 2015–2020

• Collaborative Research: Stable Isotope Systematics of Gold-silver Telluride Deposits: A Theoretical and Experimental Approach

  NSF · $167k · 2011–2015

• Iron isotope fractionation in solution

  NSF · $184k · 2007–2010

• Theoretical Stable Isotope Geochemistry of Alkaline-Earth Elements

  NSF · $248k · 2004–2008

Frequent coauthors

• Edward Young

  Planetary Science Institute

  51 shared

• Anat Shahar

  Carnegie Institution for Science

  19 shared

• P. S. Hill

  California State University, Long Beach

  16 shared

• C. E. Manning

  13 shared

• K. Ziegler

  12 shared

• John M. Eiler

  11 shared

• A. Kavner

  University of California, Los Angeles

  11 shared

• Mojhgan Haghnegahdar

  University of Maryland, College Park

  10 shared

Education

• Ph.D., Earth and Space Sciences

  University of California, Los Angeles

  1995

• M.S., Earth and Space Sciences

  University of California, Los Angeles

  1991

• B.S., Earth and Space Sciences

  University of California, Los Angeles

  1989