the.com/lithosphere
earth's crust plus the rigid top of the mantle, floating on the gooey stuff underneath like a cracker on soup.
means the solid outer shell of a rocky planet, made of tectonic plates that ride on the softer, flowing mantle beneath.
from from greek lithos meaning stone plus sphaira meaning sphere, coined by geologists in the early 1900s to distinguish rigid rock from the ductile asthenosphere below it.
thickness varies100km under continents, 50km under oceans
broken into piecesabout 15 major tectonic plates
floats onthe asthenosphere, which flows like tar
not just crustincludes uppermost solid mantle too