Columbia Encyclopedia

(Encyclopedia) Zagros zăgˈrŏs [key], mountain system of W Iran, extending c.1,100 mi (1,770 km) from the Turkish-Armenian frontier SE to the Strait of Hormuz, forming the western and southern border of the centra...

(Encyclopedia) pitchblende pĭchˈblĕndˌ [key], dark, lustrous, heavy mineral, a source of radium and uranium. Largely natural uranium oxides, triuranium octaoxide (U3O8) and uranium dioxide (UO2), it usually cont...

(Encyclopedia) Spokan or Spokane both: spōkănˈ [key], Native North Americans whose language belongs to the Salishan branch of the Algonquian-Wakashan linguistic stock (see Native American languages). In the early...

(Encyclopedia) Salt River valley, irrigated region around the lower course of the Salt River, which rises in mountain streams near the Mogollon Rim of the Mogollon Plateau and flows southwest to join the Gila River ...

(Encyclopedia) Ellesmere Island, 82,119 sq mi (212,688 sq km), c.500 mi (800 km) long, in the Arctic Ocean, N Nunavut Territory, Canada; second largest and northernmost island of the Arctic Archipelago. It is separa...

(Encyclopedia) Grand Banks, submarine plateau rising from the continental shelf, c.36,000 sq mi (93,200 sq km), off SE Newfoundland, N.L., Canada. It is c.300 mi (480 km) long and c.400 mi (640 km) wide; depths rang...

(Encyclopedia) Fribourg frīˈbûrg, Fr. frēbo͞orˈ [key], Ger. Freiburg, canton , 645 sq mi (1,671 sq km), W ...

(Encyclopedia) lava läˈvə [key], molten rock that erupts on the earth's surface, either on land or under the ocean, by a volcano or through a fissure. It solidifies into igneous rock that is also called lava. Bef...

(Encyclopedia) Sierra Madre dĕl so͝orˈ [key] is a tumbled, broken mass of uptilted mountains that touch the Pacific coast but form into no clearly defined range. It spreads over S Mexico between the volcanic belt...

(Encyclopedia) Massif Central mäsēfˈ säNträlˈ [key] [Fr.,=central highlands], great mountainous plateau, c.33,000 sq mi (85,470 sq km), S central France, covering almost a sixth of the surface of the country. ...