The movie October Sky, isn't strictly a geology movie, but it does feature a young man, Homer Hickam, who desperately wants not to follow his father into the local coal mines, but who instead wants to go into space: from deep inside the earth to way up into the sky and beyond. Based on a true story.
It's a good movie, IMO, and it's on tonight and tomorrow night on DIRECTV:
October Sky on AMC at 8:00 PM EST, 01/12/2009
October Sky on AMC at 5:30 PM EST, 01/13/2009