There was an animated film showing how rock were formed in the earth

Try the movie,.

Dig (72)

Talking rocks take a boy and his dog on a magical
Musical journey beneath the earth.

-more info- (http://www.pbs.org/itvs/independentspirits/filmography.html)


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Part 1 -- Dig (1972, John Hubley) - Part 1/2 - YouTube (http://www.youtube.com/watch?v=zY2GeH1P44k)

Part 2 -- Dig, Part 2 (http://www.youtube.com/watch?v=zY2GeH1P44k)