Lithosphere 50–140 km thick (but beneath the mid-ocean ridges is no thicker than the crust), while continental lithosphere has a range in thickness from about 40 km to perhaps 280 km; the upper ~30 to ~50 km of typical continental lithosphere is crust. The mantle part of the lithosphere consists largely of peridotite. The crust is distinguished from the upper mantle by the change in chemical composition that takes place at the Moho discontinuity. Oceanic lithosphere consists mainly of mafic crust and ultramafic mantle (peridotite) and is denser than continental lithosphere, for which the mantle is associated with crust made of
What on Earth 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 were rebroadcast from July to September 1971, in