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! Pindal in December 1963, with the working title "Automation", with the intention of showing how "in spite of appearances, man is the master in the automated world." The working title would become "Martians", before the final title "What on Earth!" was chosen. Drew was brought in to work on the film in 1965 and 1966, with Brittain assigned to write narration. Pindal's original idea of "man as the master" is not reflected in the final version of the film, and NFB archivist and blogger Albert Ohayon believes Brittain may have been responsible for this key change. "What on Earth!" was