If the asthenosphere was made of rigid rock, like the lithosphere, do you think tectonic plates would move the same way? Would we still have landforms like mountains, volcanoes, and rift valleys?

sediment layers stop spreading when they reach a barrier or they run out of sedimentary material. lateral spreading is the movement of gently to steeply sloping, saturated soil deposits caused by earthquake-induced liquefaction. i hope this . : )