Trace Metal Isotope Geochemistry, Spring 2009

Notable Publications


Trace Metal Isotope Geochemistry group, clockwise from far left: Dr. Hai Cheng, Dr. Larry Edwards, Megan Kelly, Ben Hardt, Dr. Xianfeng Wang, Allison Burnett, Dr. Ronny Boch, Dezhong Zhang, Carolyn Dykoski, Xiaoyan Zhu

The trace metal isotope geochemistry group (TMIG), led by Dr. Larry Edwards, has had another busy year in the lab and abroad.  Much of their work continues to focus on uranium-series dating of cave deposits to obtain very precise records of past climatic changes. Other areas and techniques the group has been working on include U-series dating of corals, as well as U-series oceanographic tracers. 

Dr. Hai Cheng, Research Scientist and Lab Manager, has been focused on the development and application of U-series dating techniques to address fundamental issues on palaeoclimatology, palaeoceanography, human evolution, and global climate change researches.  Currently, his main research project is the reconstruction of the Asian Monsoon and Central Asian climate history over the past 600 ky and the establishment of its correlation to ice core, marine and various regional records which provides a key to understand global climate change.

Dr. Xianfeng Wang, Postdoctoral Associate, is using speleothem samples from Brazilian caves to restore the history of South American Summer Monsoon over the last 300 ky and investigate the mechanisms of millennial-scale climate events during the glacial times.  He is also involved in projects to characterize chemical behavior of uranium-series elements and isotopes in sea water and marine sediment.

Dr. Sushmita Dasgupta graduated last spring; her work focused on a speleothems from a series of Midwestern caves used to reconstruct Holocene climate.  She took a job with Schlumberger and is currently living in Houston. 

Current graduate students include Carolyn Dykoski, Megan Kelly, Ben Hardt and Allison Burnett. 

Megan Kelly is studying the history and variability of the Asian Monsoon over the last several glacial-interglacial cycles using stalagmites from a cave in southern China, and hopes to graduate with a Ph.D. degree in Spring 2009.

Ben Hardt has been working with colleagues from the University of Ohio and University of Texas-Arlington on samples from West Virginia.  The oxygen isotopes in these speleothems appear to track regional changes in summer precipitation relative to the rest of the year.  Such variations in seasonal precipitation suggest that atmospheric circulation patterns vary on glacial/interglacial scales with increased meridional transport of moisture during insolation maxima.

Last summer, Allison Burnett had the opportunity to do clumped isotope paleothermometry at CalTech on several Midwestern speleothem samples.  She is currently measuring the uranium isotopic composition of seawater samples to study oceanic circulation.

 The group has also had numerous visitors over the past year.  Dr. Ronny Boch joined the group for an extended research stay as a visiting Post Doc from the Leopold-Franzens-Universität Innsbruck, Austria. He is analyzing speleothems of Last Glacial age from cave sites at the northern rim of the Alps in Austria, Switzerland and Germany.  He hopes to compare Dansgaard-Oeschger cycles from these records to the Greenland ice cores to gain new insights into the progression of rapid climate changes during the Last Glacial in Central Europe.

This summer, Julie Retrum, currently at University of Kansas, will be joining us on a NSF postdoctoral fellowship.

Other visitors from the past year include:


Dr. Christoph Spötl (University of Innsbruck)



Mr. Alexandre Seidel (University of São Paulo)

Dr. Francisco W. Cruz (University of São Paulo)



Dr. Zhisheng An (Institute of Earth Environment, Chinese Academy of Sciences)

Dr. Yanjun Cai (Institute of Earth Environment, Chinese Academy of Sciences)

Mr. Xiuyang Jiang (Nanjing Normal University)

Mr. Kan Zhao (Nanjing Normal University)

Mr. Dezhong Zhang (Lanzhou University)

Ms. Xiaoyan Zhu (Institute of Karst, Chinese Academy of Geological Sciences)



Dr. Mayuri Inoue (University of Tokyo)



Prof. Javier Martin-Chivelet (Universidad Complutense, Madrid)

Dr. Maria Turrero (Universidad Complutense, Madrid)

Dr. Ana Moreno (Pyrenean Institute of Ecology-CSIC, Zaragoza)



Dr. Chuan-Chou (River) Shen (National Taiwan University)

Mr. Chung-Che Wu (National Taiwan University)



United States:

Dr. Yemane Asmerom (University of New Mexico)

Dr. Christina Gallup (University of Minnesota, Duluth)

Ms. Brittany Guzzo (University of Iowa)

Dr. Fuyuan Liang (University of Georgia)

Mr. David McGee (Columbia University)

Dr. Martin Medina-Elizalde (University of Massachusetts, Amherst)