Transmogrification of ocean into continent: implications for continental evolution

SignificanceThis study proposes a geological mechanism for creating continental crust and lithosphere. When continents collide, the typical embayments and protrusions along their rifted margins make it likely that fragments of seafloor will be trapped within the growing mountain belt. These become preferential centers of sedimentation that eventually convert former seafloor into a unique form of continental crust and lithosphere, leading to characteristic temporal changes in the relative strength and uplift/subsidence of these regions. The Alpine-Himalayan mountain chain in Eurasia shows several stages of this process, which we further explore with a one-dimensional thermal-rheological model. In Asia, this process appears to have created a characteristic paired-mountain belt geomorphology (Himalaya/Tibet + Tian Shan) that has greatly strengthened the East Asian Monsoon.