Lithosphere Lithosphere A lithosphere ( ["lithos"] for "rocky", and ["sphaira"] for "sphere") is the rigid, outermost shell of a terrestrial-type planet, or natural satellite, that is defined by its rigid mechanical properties. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater. The outermost shell of a rocky planet, the crust, is defined on the basis of its chemistry and mineralogy. The study of past and current formations of landscapes is called geomorphology. Earth's lithosphere includes the crust and the uppermost mantle, which constitute
Expanding Earth of action. During the 1960s, the theory of plate tectonics—initially based on the assumption that Earth's size remains constant, and relating the subduction zones to burying of lithosphere at a scale comparable to seafloor spreading—became the accepted explanation in the Earth Sciences. The scientific community finds that significant evidence contradicts the Expanding Earth theory, and that evidence used in support of it is better explained by plate tectonics: Expanding Earth The expanding Earth or growing Earth hypothesis asserts that the position and relative movement of continents is at least partially due to the volume of Earth increasing. Conversely, geophysical global