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! 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