September 19, 2016
Graduate student Miquela Ingalls, Assistant Professor Albert Colman, and Professor David Rowley have published a paper in Nature Geoscience titled, "Large-scale subduction of continental crust implied by India-Asia mass-balance calculation." In the paper, they calculate the mass of continental crust that existed in India and Tibet before collision (60Ma), and the mass in the system today. They account for mass accommodation by potential crustal thickening in Tibet, "tectonic escape" of the southeast Asian micro-plates, and erosion into the Indian Ocean, and find 50% of the pre-collisional continental crust is missing from the Earth's surface today. This leads them to the suggestion that wholesale subduction of lower crustal eclogite into the mantle could have been an important process in past continent-continent collisions throughout Earth's history, and could contribute significantly to the evolution of mantle geochemistry.