O: Oakland oasis oblique-slip fault obsidian ocean ocean basin ocean current ocean trench ocean wave ocean-ocean convergence zone oceanic oceanic crust oceanic hot spot oceanic spreading ridge oceanographer oceanography oil oil migration oil well Okeefanokee Swamp old age Old River Old River Control Project olivine Olympus Mons open aquifer open-pit mine operation ophiolite Orange County Orange County Water District orbit Ordovician ore ore deposit organic material organism orientation origin original horizontality orogeny orthoclase outcrop outer core outer planet over-bank discharge over-steepening overlapping moraine overview oxidation oxygen oyster ozone
U.S. Department of the Interior | U.S. Geological Survey URL: http://walrus.wr.usgs.gov/infobank/programs/html/school/O_keywords.html Page Contact: InfoBank staff Page Last Modified: Tue Dec 16 06:27:35 PST 2008 (wcs)