geochronology, geodynamics, Asian tectonics
I'm currently working in two areas: regional-scale tectonics and geodynamics (often with a focus in the Himalaya, Tibet, and Asia), and refinement of techniques in thermochronology. I'm particularly interested in the influence 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). Though we have particular expertise in lower-temperature thermochronology, our work generally involves integrating such data with results from multiple dating methods and constraints obtained from other disciplines.
In May 2012 we took delivery of a juicy new Argus VI multicollector noble-gas mass spectrometer which is now in routine operation. Most recently we're using diode-laser heating to investigate U-Th/He analysis using cumulative heating. But through it all the lab remains proudly Acronym-Free!>
- Lhasa Block Top to Bottom--Lithospheric Evolution of Asia's Leading Edge (active)
- Together with a large group of colleagues at other institutions, we are using the Lhasa Block in southern Tibet as a natural laboratory to examine crustal evolution of a convergent margin across the transition from convergence to collision. 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 multidisciplinary five-year project, funded by the Continental Dynamics Program of the U.S. National Science Foundation, involves a number of investigators from institutions in the U.S., China, and Europe. 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. Field work started in May 2012. Jen Schmidt here at Lehigh is working on this project as part of her Ph.D. dissertation.
- Evolution of the Hangay Mountains in North-Central Mongolia (active)
- 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. Lenny Ancuta and Kalin McDannell here at Lehigh are working on their Ph.D. degrees as part of this project, on basalt geochemistry and geochronology, and thermochronology. Our goal is to use seismology, geomorphology, geochronology and themochronology, paleo-elevation studies, and geochemistry and petrology to understand the timing and origin of the enigmatic Hangay Mountains, a broad domal region south of the Baikal rift that reaches elevations of 4000 meters. This project started in earnest in 2011, and was funded by the Continental Dynamics Program of the U.S. National Science Foundation.
- Little Devil's Postpile Revisited: Intercalibration of Themochronometer Kinetics (active)
- This project revisits a classic locality in thermochronology, Little Devil's Postpile in Yosemite National Park, where Calk and Naeser conducted their seminal study showing how a younger basalt intrusion had systematically and predictably reset fission-track ages of apatite and sphene in the surrounding Sierra granite. This work will be a collaboration between me, Peter Reiners at Arizona, David Shuster at Berkeley Geochronology Center, and Rich Ketcham at Texas; Lehigh Ph.D. candidate Jen Schmidt is also part of the project. This field site offers the opportunity to intercalibrate and assess some 10-15 thermochronometers based on the U-He, Ar-Ar, and fission-track systems. This project is funded by the Petrology and Geochemistry program at the National Science Foundation, and work began in 2011.
- Helium Solubility and Diffusion Kinetics in Apatite and Zircon (wrapping up)
- Interest in (U-Th)/He dating has blossomed due to the low-temperature sensitivity of helium diffusion in apatite and other accessory minerals like zircon. 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. 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. Eva Enkelmann and I have been testing this idea through a series of diffusion experiments in samples in which alpha damage has been annealed and varying levels of fission-track damage have been artificially induced. Work on this project has also branched into studies of He solubility in apatite, in collaboration with Bruce Watson and Jay Thomas at RPI. Supported by the Petroleum Research Fund.
Recently Completed Projects
- U-Th/He Dating and Topographic Evolution of the Appalachians
- This long-running project is an investigation of the post-orogenic erosion and topographic history of the Appalachians, using U-Th/He dating of apatite. This work was spearheaded by Ph.D. candidate (and now recipient!) Ryan McKeon, in collaboration with Frank Pazzaglia and Bruce Idleman here at Lehigh. This work was funded by the Tectonics program at NSF.
- STEEP - St. Elias Erosion and Tectonics Project
- This large multi-investigator project has been using the St. 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 my recently-departed postdoc Eva Enkelmann) were involved as part of a team of geochronologists that documented the cooling and erosion history of the orogen.
- Geodynamics of Indentor Corners
- Focused on the eastern end of the Himalaya-Tibet collision zone, this large multidisciplinary study looked at the complex 4D deformation near a plate edge during collision, at all scales: locally, to see if the metamorphic massif and mountain Namche Barwa is an erosionally induced "tectonic aneurysm" as we proposed for Nanga Parbat; regionally, to look at the importance of erosional mass removal in the accommodation of collisional convergence; and margin-wide, to understand the reponse of the entire lithosphere to plate-edge dynamics. Based at Lehigh and also involving Anne Meltzer and her seismology research group, the project includes investigators from a number of universities. Funded by NSF-Continental Dynamics. Work on this project is largely complete and we are in the process of finishing final publications.
Students & Student Opportunities
- Lenny Ancuta (Ph.D. candidate, dating, stratigraphy, and geochemistry of Hangay-Mountain basalts, and thermochronology and isotope-geochemistry of lower-crustal xenoliths, Mongolia)
- Kalin McDannell (Ph.D. candidate, thermochronology and landscape evolution of the Hangay Mountains, Mongolia; thermochronological assessment of craton stability; rapid sample screening and correction of U-Th/He apatite ages)
- Jen Schmidt (Ph.D. candidate, kinetic intercalibration of thermochronometers using the Little Devil's Postpile intrusion, Yosemite; unroofing history of the SE Lhasa Block, Tibet)
- Darwin Janes (M.S. candidate, helium diffusion systematics in apatite and zircon)
- Janelle Thumma (M.S. candidate, timing of deformation and lndscape evolution, Gobi Altai, Mongolia)
I'm always on the lookout for students interested in tectonics, geodynamics, or applications of geochronology and thermochronology to tectonics. I feel strongly that student training should include a blend of field work, applied studies that use modern techniques to solve geological problems, and laboratory experiments that help us better understand the tools we use. I also think that graduate training should be broad, aimed at developing skills like critical thinking and synthesis of data. I'm supportive of students who seek training across earth systems and beyond, and wish to pay some attention to career development and polishing professional skills.
Intellectual life in the EES department is diverse, as you'll see if you browse through our graduate course offerings and research portfolio. 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.
Facilities for research in geochronology include systems for U-Th/He and 40Ar/39Ar geochronology (with both furnace, and UV and CO2 lasers). 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. Extensive computing facilities for data analysis include workstations provided in the geochronology lab and the department; GIS software is available on departmental machines and widely used.
Recent and Representative Publications
Zeitler, P.K., Meltzer, A.S., Brown, L., Kidd, W.S.F., Lim, C., and Enkelmann, E., 2014. Tectonics and topographic evolution of Namche Barwa and the easternmost Lhasa Block, in Nie, J., Hoke, G.D., and Horton, B., eds., Towards an improved understanding of uplift mechanisms and the elevation history of the Tibetan Plateau. Geological Society of America Special Paper, v. 507, doi: 10.1130/2014.2507(02).
Koons, P.O., Zeitler, P.K., Hallet, B., 2013. 5.14 Tectonic aneurysms and mountain building. In: Shroder, J. (Editor in Chief), Treatise on Geomorphology. Academic Press, San Diego, CA, vol. 5, pp. 318-349, doi: 10.1016/B978-0-12-374739-6.00094-4.
Enkelmann, E., Zeitler, P.K., Garver, J.I., Pavlis, T.L., and Hooks, B.P., 2010. The thermochronological record of tectonic and surface process interaction at the Yakutat-North American collision zone in southeast Alaska. American Journal of Science, 310, 231-260., doi: 10.2475/04.2010.01.
Enkelmann, E., Zeitler, P.K., Pavlis, T.L., Garver, J.I., and Ridgway, K.D., 2009. Intense localized rock uplift and erosion in the St Elias orogen of Alaska. Nature Geoscience, v. 2, no. 5, p. 360-363. DOI: 10.1038/NGEO502. (pdf)
Finnegan, N.J., Hallet, B., Montgomery, D.R., Zeitler, P.K., Stone, J.O., Anders, A.M., and Liu Yuping, 2008. Coupling of rock uplift and river incision in the Namche Barwa-Gyala Peri massif, Tibet. Geological Society of America Bulletin, v. 120(1/2); p. 142-155; doi: 10.1130/B26224.1. (pdf)
Stewart, R.J., Hallet, B., Zeitler, P.K., Malloy, M.A., Allen, C.M., and Trippett, D., 2008. Brahmaputra sediment flux dominated by highly localized rapid erosion from the easternmost Himalaya. Geology, v. 36, p. 711-741, doi: 10.1130/G24890A.1. (pdf)
Sol, S., Meltzer, A.S., Bürgmann, R., Van der Hilst, R.D., King, R., Chen, Z., Koons, P., Lev, E., Liu, Y.P., Zeitler, P.K., Zhang, X., Zhang, J., and Zurek, B., 2007. Geodynamics of the southeastern Tibetan plateau from seismic anisotropy and geodesy. Geology, 35, 563-566 (DOI: 10.1130/G23408A.1).
Koons, P. O., Zeitler, P.K., Chamberlain, C.P., Craw, D., Meltzer, A.S. 2002. Mechanical links between erosion and metamorphism in Nanga Parbat, Pakistan Himalaya. American Journal of Science, 302, 749-773. (pdf)
Zeitler, P. K., A. S. Meltzer, P. Koons, D. Craw, B. Hallet, C. P. Chamberlain, W. Kidd, S. Park, L. Seeber, M. Bishop, J. Shroder, 2001. Erosion, Himalayan geodynamics, and the geology of metamorphism. GSA Today, 11, 4-8. (pdf)
Zeitler, P.K., Koons, P.O., Bishop, M. L., Chamberlain, C.P., Craw, D., Edwards, M.A., Hamidullah, S., Jan, M.Q., Khan, M.A., Khattak, M.U.K., Kidd, W.S.F., Mackie, R.L., Meltzer, A.S., Park, S.K., Pecher, A., Poage, M.A., Sarker, G., Schneider, D.A., Seeber, L., and Shroder, J., 2001. Crustal Reworking at Nanga Parbat, Pakistan: Metamorphic consequences of thermal-mechanical coupling facilitated by erosion. Tectonics, 20, 712-728. (pdf)
Zeitler, P.K., Chamberlain, C.P., and Smith, H.A., 1993. Synchronous anatexis, metamorphism, and rapid denudation at Nanga Parbat (Pakistan Himalaya), Geology, 21, 347-350. (pdf)
Cerveny, P.F., Naeser, N.D., Zeitler, P.K., Naeser, C.W. and Johnson, N.M., 1988. History of uplift and relief of the Himalaya over the past 18 Ma - Evidence from fission-track ages of detrital zircons from sandstones of the Siwalik Group, in K. Kleinspehn and C. Paola, eds., New Perspectives in Basin Analysis, Univ. Minnesota Press, p. 43-61. (pdf (10MB!))
Zeitler, P.K., 1987. Argon diffusion in partially outgassed alkali-feldspars: Insights from 40Ar/39Ar analysis. Chemical Geology (Isotope Geoscience Section). 65, 167-181. (pdf)
Zeitler, P.K., Herczeg, A., McDougall, I., and Honda, M., 1987. U-Th-He dating of Durango fluorapatite: a potential thermochronometer. Geochimica et Cosmochimica Acta. 51, 2865-2868.