Crustal thickening is a geological process where the Earth's crust becomes thicker due to tectonic forces, such as continental collision or magmatic addition, leading to the formation of mountain ranges and plateaus. This process plays a critical role in the evolution of continental crust and affects regional geology, topography, and seismic activity.
The lithosphere-asthenosphere boundary (LAB) is the transition zone between the rigid, outermost shell of the Earth (the lithosphere) and the more ductile, partially molten layer beneath it (the asthenosphere). This boundary is crucial for understanding plate tectonics as it allows the lithospheric plates to move over the more fluid asthenosphere, facilitating processes like continental drift and seafloor spreading.