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
What on Earth June 1975 and from May to August 1977. What on Earth What on Earth is a Canadian television panel game show and discussion program which aired on CBC Television from 1971 to 1975. It was based on the 1959 CBC game show "Who Knows?" The series featured items from the Royal Ontario Museum, the Ontario Science Centre and other facilities. These were brought before a panel who attempted to identify the objects. After the object's identity was guessed or revealed, it was the subject of further conversation by participants. This half-hour series was broadcast as follows (times in Eastern): Episodes