00471 a2200193 4500 551.136 BAL 30306 53104 Ballard, Robert D Exploring our living planet Washington National geographic society 1983 1983 366p. 29cm Planet earth Fire Plate tectonics Geology Crust Mountains Mountains SR 56816 56816 0 0 0 0 SRC MAIN MAIN REF 2014-07-01 0 551.136BAL 32580 2017-09-01 00:00:00 0.00 2016-10-31 SR