Academic Background

2009-present:  Assistant Professor, Earth and Planetary Sciences,  Johns Hopkins University.

2007-2009: Dreyfus Postdoctoral Scholar in Environmental Geochemistry, Caltech.

2007:  Doctor of Philosophy in Geology, University of Utah.  

2004:  Master of Science in Geology, University of Utah.

Thesis title: “Forward and inverse models of time-averaging in intra-tooth isotope profiles.”

2001:  Bachelor of Science in Geology, University of Utah. 

Undergraduate project:  “Environmental change in the Great Plains: An isotopic record from fossil horses.”

Teaching

Spring 2011: EPS 270.377 (JHU) Climates of the Past (grad/upper-level ugrad)

Fall 2010: EPS 270.103 (JHU) Introduction to Global Environmental Change (ugrad lower-level)

Fall 2010: EPS 270.633 (JHU) Advanced Topics in Isotope Geochemistry (grad seminar).  Semester theme: Stable Isotopes in Animal Body Water

Spring 2010: EPS 270.313 (JHU) Isotope Geochemistry (grad/upper-level ugrad)

Spring 2007:  GG 3090 (U. Utah) Earth Materials II (lower-level ugrad).  Part semester instructor. 

Fall 2006:  GG 5660 (U. Utah) Geochemistry (upper-level ugrad), Teaching Assistant.

Fall 2006:  GG 4100 (U. Utah) Optical Mineralogy and Petrology (upper-level ugrad), Teaching Assistant.

Spring 2004: GG 3300 (U. Utah) The Water Planet (gen ed class), Teaching Assistant.

June 02-05:  BIOL 6470 (U. Utah) SIRFER stable isotope short course, Laboratory Assistant.

Grants and Awards

2010: American Chemical Society, Petroleum Research Fund (PRF#50321-DNI2).  Carbonate 'clumped isotope' thermometry: Constraining closure temperatures for the 13C-18O order/disorder process in carbonate minerals. July 1, 2010 - Aug 31, 2012.

2010: NSF-BCS-Archeology (BCS-0948310).  Collaborative research: Rodent diets and habitat reconstructions in South Africa: an actualistic and applied multidisciplinary study.  March 1, 2010 - Feb 29, 2012 (co-PI with M. Sponheimer and P. Ungar).

2007: 'Outstanding PhD student, 2007', Department of Geology and Geophysics, University of Utah. 

2005:  GSA student research grant.  “Late Miocene terrestrial environments and C4 vegetation in north-central China: An isotopic record from fossil mammals and soil carbonate”

2005:  Outstanding student talk, North Central GSA. Title “Improvements in laser ablation GC/IRMS (d13C, d18O) methodology for isotopic analysis of small bioapatite samples."

2004:  Associated Students of the University of Utah, stipend for travel to China.

2002:  ‘Outstanding MS student, 2002’, Department of Geology and Geophysics, University of Utah.

1999:  ‘Undergrad student of the Year’, Department of Geology and Geophysics, University of Utah.

Laboratory Experience

2009-present (Johns Hopkins): Establishment of a new stable isotope lab at Johns Hopkins University.  Thermofinnigan MAT 253 mass spectrometer, automated carbonate device for carbonate 'clumped isotope analysis', laser ablation extraction line for d13C and d18O analysis of bioapatites, offline glass vacuum line.

2007-2008 (Caltech): Design, construction, and implementation of an online, automated sample prep system for analysis of clumped isotopes in carbonate.  This system runs in a custom-programmed Labview vi, and features automated valve control, x-y lifter control, GC control, and coupling with the ThermoFinnigan Isodat software interface.

2004-2005 (Utah): Development of laser ablation methods for stable isotope analysis of bioapatite.

Spring + Summer 2003 (Utah):  Helped to set up a new stable isotope lab (Cerling Lab, Department of Biology facility), including online automated peripherals and offline vacuum prep lines.

Computational approaches using Matlab, ImageJ, Volsuite, Imod, Labview for addressing forward and inverse geobiological problems, image processing, and 3-D processing and visualization of volumetric data.

2000 – 2006:  Design and implementation of controlled-feeding experiments on large and small mammals (in collaboration with Brigham Young University Animal Science and University of Utah Biology) aimed at establishing diet-tissue fractionation factors, characterizing tooth development, and establishing turnover rates of C, H, O, and N in animal systems.       

Fieldwork

November 2010: Egypt, Fayum Depression.  Eocene-Oligocene environmental and biotic change (with Eric Seiffert, Tom Bown, Prithijit Chatrath, Elwyn Simons, Mark Mathison).

July 2010: USA, Wyoming, Bighorn Basin.  Early Eocene paleoenvironments (with Ken Rose, Amy Chew, Naomi Levin, Marina Suarez, Rebecca Kraft).

July 2007, June-July 2008:  China (Inner Mongolia) Investigation of Miocene fossil mammal localities and associated sediments (with Mikael Fortelius, Zhang Zhaoqun, Liu Liping, Anu Kaakinen, and others).

September 2004, 2005:  China (Shanxi Province). Sedimentology and stable isotope stratigraphy of the late Neogene ‘hipparion’ red clay  and loess deposits (with Mikael Fortelius, Zhang Zhaoqun, Anu Kaakinen, and others).

August 2003:  Australia. Continent-wide sampling of modern faunal remains, plants, and natural waters for stable isotope ecology studies (with Linda Ayliffe).

Dec. 2001, June 2002:  Argentina (Catamarca Province). Tephra-stratigraphy and stable isotope survey of late Miocene through Pleistocene terrestrial deposits (with Thure Cerling, Pepe Prado and Scott Hynek).

Aug. 2000, Jan. 1999:  Kenya, Ethiopia. Turkana basin geology, and modern floral and faunal collections from national parks (with Frank Brown, Thure Cerling, and John Harris).

Professional Meetings   

June 2010: Goldschmidt Conference, Knoxville, Tennessee. Poster: 'Experimental study of solid-state ¹³C-¹⁸O bond reordering in calcite'.

April 2010: Quaternary Research Center Spring Workshop: First International Meeting on Clumped Isotope Geochemistry, April 15-17, 2010.  Talk title: ‘Clumped isotopes in recent and fossil soil carbonates’.

December 2009: BH Passey, JM Eiler, M Daeron, J Quade, CN Garzione, JJ Smith, TE Cerling, NE Levin (2009)  'Clumped isotope' paleothermetry of soil carbonates: a status report.  EOS Trans. 90(52) AGU, Fall Meet. Suppl., AbstractPP12B-01

April 2009: NESCent Catalysis Group Meeting: Towards a new synthesis of the evolutionary history and ecology of C4 grasses, Durham, North Carolina, talk title: New school and old school views on C4 grass expansion during the Neogene.

December 2008: AGU Fall Meeting, San Francisco, California, talk title: Barefoot on hot ground: Formation temperatures of Plio-Pleistocene soil carbonates in East Africa based on the clumped isotope in carbonate (D47) thermometer.  EOS Trans. AGU, 89(53), Fall Meet. Suppl., Abstract PP11D-02.  with JM Eiler, NE Levin, TE Cerling.

August 2008: Isoecol VI, Honolulu, Hawaii, talk title: "Cut-and-dried: leaf water is the primary amplifier of an aridity signal in animal body water d18O", with TF Robinson, JW Singer, and TE Cerling.

June 2006:  2nd International Palaeontological Congress, Beijing, China, talk title: “A regionally resolved history of C4 vegetation in North China since the late Miocene”, with LK Ayliffe, TE Cerling, M Fortelius, A Kaakinen, JT Eronen, and Z Zhang.

October 2005:  Society of Vertebrate Paleontology, Mesa, Arizona, talk title: “Paleoenvironments and mammal communities of the Late Neogene Red Clay at Baode, Shanxi, North China”, with M Fortelius, A Kaakinen, YM Zhu, Z Zhang, and LP Zhou.

October 2005:  Society of Vertebrate Paleontology, Mesa, Arizona, talk title: “Equid d18O in the Neogene of Nebraska: Relationship with ungulate diversity, and discussion of mammalian d18O as a paleoenvironmental proxy”, with TE Cerling.

June 2005:  First International Workshop on Taphonomy and Biochemistry Applied to Human and Environmental Sciences, Paris, France, talk title: “The role of x-ray microCT, linear systems, and inversion theory in the meaningful interpretation of intra-tooth isotope profiles”, with TE Cerling.

May 2005:  Geological Society of America North Central Section, Minneapolis, Minnesota, talk title: “Improvements in laser ablation GC/IRMS (d13C, d18O) methodology for isotopic analysis of small bioapatite samples”, with TE Cerling.

November 2003:  Geological Society of America Annual Meeting, Seattle, Washington poster title: Dam Fun: Interactive teaching of sedimentological and hydrological principles using a see-through dam-reservoir model”, with TE Cerling and MA Chan.

November 2003:  Geological Society of America Annual Meeting, Seattle, Washington poster title: “Inversion of stable isotope signals in tooth enamel: recovering the primary isotope time-series”, with TE Cerling, Gerard T. Schuster.

October 2001:  Society of Vertebrate Paleontology, Bozeman, Montana talk title: “Seasonal isotopic data from Nebraska fossil horses, and insights from developing cow molars”, with TE Cerling, LK Ayliffe, M Sponheimer, J Hammer, TF Robinson, and B Roeder.

October 1999:  Geological Society of America Annual Meeting, Denver, Colorado poster title: “Timing and nature of C4 biomass expansion in Nebraska”, with TE Cerling, M Perkins, ST Tucker, MR Voorhies.

Publications (click link)

Referee Service

Palaeo-3, Chemical Geology, Geochimica et Cosmochimica Acta, Oecologia, Journal of Archaeological Science, Global Ecology and Biogeography, Ecology, Science, Naturwissenschaften, PNAS