U th he dating of apatite a potential thermochronometer
Most recently we're using diode-laser heating to investigate U-Th/He analysis using cumulative heating. We wish to examine how the early history of a convergent margin can impact later development of the collisional margin, integrating data from studies in geochemistry, geochronology, paleoelevation studies, seismology, tectonics, and thermo-mechanical modeling. This large project is a collaboration with Anne Meltzer, Bruce Idleman, and Dork Sahagian at Lehigh, Karl Wegmann at North Carolina State (Karl is lead PI for the whole project), Rick Carlson at DTM, Page Chamberlain at Stanford, and colleagues from the Mongolian Institute of Science and Technology and also the Center of Astronomy and Geophysics at the Mongolian Academy of Sciences.
This multidisciplinary five-year project, funded by the Continental Dynamics Program of the U. National Science Foundation, involves a number of investigators from institutions in the U. The PIs include Zeitler and Anne Melzer at Lehigh, Don Depaolo (Project Coordinator) at Berkeley, An Yin and Mark Harrison at UCLA, David Rowley at Chicago, David Shuster at the Berkeley Geochronology Center and Berkeley, Frederic Herman at ETH in Zurich, and Mo Xuanxue, Zhidan Zhao, and Di-cheng Zhu at China University of Geosciences. Jen Schmidt here at Lehigh is working on this project as part of her Ph. Lenny Ancuta and Kalin Mc Dannell here at Lehigh are working on their Ph. degrees as part of this project, on basalt geochemistry and geochronology, and thermochronology.
Elias range in Alaska to investigate the role of glacial erosion in shaping the tectonics of an active orogenic belt, and also what other driving forces and boundary conditions are causing deformation in the region.
Lehigh personnel (me, and postdoc at the time Eva Enkelmann) were involved as part of a team of geochronologists that documented the cooling and erosion history of the orogen.
However, helium diffusion is complicated by accumulation of radiation damage: damage zones appear to act as internal traps for helium, having the net effect of increasing helium retentivity. Comment on “Tectonic control of Yarlung Tsangpo Gorge revealed by a buried canyon in Southern Tibet.” Science, 349(6250):799, doi:10.1126/science.aaa9380.
Contrary to the common assumption that alpha-recoil damage is responsible for this phenomenon, we hypothesize that the much more rare fission-track damage might in fact be an important controlling factor as well.
Intellectual life in the EES department is diverse, as you'll see if you browse through our graduate course offerings and research portfolio. Journal of Geology, 124, 435-445, DOI: 10.1086/686272.
It's also worth knowing, especially from the perspective of broader career development, that courses in departments like Civil & Environmental Engineering, Materials Science, and beyond are available to you. Relevant supporting facilities include a stable-isotope geochemistry laboratory housed within the department, and excellent facilities for sample characterization housed in other departments on campus.
I'm currently working in two areas: regional-scale tectonics and geodynamics (with a focus on the Himalaya, Tibet, and Asia), and refinement of techniques in thermochronology. The thermochronological record of tectonic and surface process interaction at the Yakutat-North American collision zone in southeast Alaska. Intense localized rock uplift and erosion in the St Elias orogen of Alaska. I'm particularly interested in the influence that surface processes have on tectonic processes and dynamics. By training I am a geochronologist, and the lab we maintain here at Lehigh carries out the full range of applications in noble-gas geochronology (U-Th/He and Ar-Ar).