If you think you know your way around, think again. A geologic map will transform the way you see your stomping grounds. The familiar featuresroads, cities, buildings and all thatare grayed out while the aboriginal land itself shines forth in colors, patterns and lines. Sprinkling this strange scene are symbols and markings with purely geological significance, things you may never have known existed. I'm saying beware: the geologic maps quiz may leave you all at sea. And I think that even the grizzled old pros may miss a trick or two in this challenging test.