Lithosphere of these xenoliths have been investigated by many methods, including analyses of abundances of isotopes of osmium and rhenium. Such studies have confirmed that mantle lithospheres below some cratons have persisted for periods in excess of 3 billion years, despite the mantle flow that accompanies plate tectonics. 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
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