Abstract
It's the summer of 1990, and Amy (age 11), Beth (age 9), and Marion (age 6) are in for the family vacation of a lifetime. No, they're not going Disneyland, Hawaii, or on a Caribbean cruise. No, they're not flying to Germany to collect pieces of the Berlin Wall. They will be looking at rocks, though. Lots of rocks. So many rocks. You see, when your father is a geologist, that's what you do on your summer vacation.