Earth Sciences Division Staff: John N. Christensen

Biographical Summary

John Christensen graduated from UC Berkeley with a BA in geology, and received his Masters and Ph.D. in geology from the University of California, Los Angeles.  He did post-doctoral work at the University of Michigan’s Dept. of Geological Sciences and stayed on as research scientist before joining the LBNL Earth Sciences Division in 1999.  In 2006 he became a staff scientist. John is an isotopic geochemist who uses MC-ICPMS and TIMS to develop techniques he uses in a wide variety of research, including basic science as well as problems in environmental science and environmental remediation. Current projects concern contaminant transport from the vadose, zone to groundwater and surface water at the Hanford Nuclear Site (WA) and the Savannah River Site (SC); the monitoring of Cr reduction/oxidation processes through isotopic fractionation, the isotopic tracking of atmospheric aerosols and ozone; the isotopic fractionation of solutes by diffusion in a variety of solvents (e.g. water, alcohol, propylene carbonate).  John is in charge of a suite of clean laboratories as well as a MC-ICPMS lab. His other research interests include paleoceanography and paleoclimatology, economic geology, geochronology, metamorphic and igneous petrology.  He also has published on the kinetics of mineral growth and metamorphic reactions, the evolution of metamorphic belts, and the genesis of MVT Pb-Zn deposits, as well as on the petrogenesis of silicic magmas, and on geochemical and isotopic records of weathering and climate change.

Education

• Ph.D., Geology, University of California, Los Angeles.
  • Dissertation: The Sr isotopic measurement of rates of tectonometamorphic processes: Case studies in Southeastern Vermont, USA and the Tauern Window, Eastern Alps
• M.S. Geology, University of California, Los Angeles.
  • Thesis: A strontium isotopic study of processes in a silicic magma chamber: the Bishop Tuff, Long Valley, California
• B.A., Geology, University of California, Berkeley.

Professional Experience

• 2006-present:  Staff Geological Scientist, Earth Science Division, Lawrence Berkeley National Laboratory.
• 1999-2006:   Geological Scientist, Earth Science Division, Lawrence Berkeley National Laboratory.
• 1997-1999:  Asst. Research Scientist, Department of Geological Sciences, Univ. of Michigan.
• 1992-1997:  Post-Doctoral Research Fellow, Department of Geological Sciences, Univ. of Michigan.

Professional Organizations

• American Geophysical Union
• Mineralogical Society of America