Continental Crust Formation
Half of Earth's radioactive heat producing elements like U, Th and K have migrated into the continental crust over the course of Earth's history. However, the crust makes up less than 0.5 % of the Earth. Primary magmas are generated in the mantle and eventually migrate to the Earth's surface, cooling, crystallizing and differentiating into a wide diversity of magma types. Felsic liquids rise to the surface and mafic cumulates are left behind in the lower crust. What are the mass fluxes of juvenile crust formation, felsic liquids and cumulates? How do these processes distribute various elements throughout the Earth? How have these processes changed with time? Our research on this topic is based on field work, geochemistry and geochemical and geodynamic modeling. We have focused much of our efforts in understanding the deep structure of volcanic arcs in the Phanerozoic.
Future directions: the origin of A-type granites and their significance to continent stabilization in the Archean; cycling of sulfur and chalcophile elements during continent formation.
Chin, E. J., Lee, C.-T. A., Barnes, J., 2014, Thickening, refertilization, and the deep lithosphere filter in continental arcs: constraints from major and trace elements and oxygen isotopes, Earth Planet. Sci. Lett.397:184-200; http://dx.doi.org/10.1016/j.epsl.2014.04.022
Chin, E. J., Lee, C.-T. A., Tollstrup, D. L., Xie, L.-W., Wimpenny, J. B., Yin, Q.-Z. 2013. On the origin of hot metasedimentary quartzites in the lower crust, Earth and Planetary Science Letters 361: 120-133.
Chin, E. J., Lee, C-T A, Luffi, P, Tice, M, 2012, Deep lithospheric thickening and refertilization beneath continental arcs: case study of the P, T and compositional evolution of peridotite xenoliths from the Sierra Nevada, California, J. Petrology 53:477-511.
Lee, C.-T. A., P. Luffi, Chin, E. J., Bouchet, R., Dasgupta, R., Morton, D. M., Le Roux, V., Yin, Q.-Z., Jin, D., 2012. Copper systematics in arc magmas and implications for crust-mantle differentiation. Science 336:64-68.
Lee, C-T A, Cheng, X., Horodyskyj, U., 2006, The development and refinement of continental arcs by primary basaltic magmatism, garnet pyroxenite accumulation, basaltic recharge and delamination: insights from the Sierra Nevada, Contrib. Mineral. Petrol. 151:222-242; (DOI 10.1007/s00410-005-0056-1).
Lee, C.-T. A., Morton, D. M., Kistler, R. W., Baird, A. K., 2007, Petrology and tectonics of Phanerozoic continent formation: from island arcs to accretion and continental arc magmatism, Earth Planet. Sci. Lett. 263: 370-387.
Morton, D. M., Miller, F. K., Kistler, R. W., Premo, W. R., Lee-, C.-T. A., Langenheim, V. E., Wooden, J. L., Snee, L. W., Clausen, B. L., Cossette, P., 2014, Framework and petrogenesis of the northern Peninsular ranges batholith, southern California, Geol. Soc. Am. Mem. 211:61-143, doi:10.1130/2014.1211(03).