Columbia Encyclopedia

Search results

500 results found

Eocene epoch

(Encyclopedia)Eocene epoch ēˈəsēnˌ [key], second epoch of the Tertiary period in the Cenozoic era of geologic time, from approximately 54.9 to 38 million years ago. The Eocene in North America was marked by th...

King, B. B.

(Encyclopedia)King, B. B., 1925–2015, African-American blues singer and guitarist, b. near Indianola, Miss., as Riley B. King. He grew up poor in the Mississippi Delta region, began playing the guitar at 12, was ...

serpentine

(Encyclopedia)serpentine sûrˈpəntēn, –tīn [key], hydrous silicate of magnesium. It occurs in crystalline form only as a pseudomorph having the form of some other mineral and is generally found in the form of...

reservoir

(Encyclopedia)reservoir rĕzˈəvôr, –vwär [key], storage tank or wholly or partly artificial lake for storing water. Building an embankment or dam to preserve a supply of water for irrigation is an ancient pra...

quartz

(Encyclopedia)quartz, one of the commonest of all rock-forming minerals and one of the most important constituents of the earth's crust. Chemically, it is silicon dioxide, SiO2. It occurs in crystals of the hexagon...

earth, in geology and astronomy

(Encyclopedia)CE5 A. Cross section of the earth, showing its shells B. Detailed cross section of the crust and upper mantle: The lithosphere consists of the hard rock in the crust and upper mantle, lying above t...

Arkansas, state, United States

(Encyclopedia)CE5 Arkansas ärˈkənsôˌ, ärkănˈzŭs [key], state in the south-central United States. It is bordered by Tennessee and Mississippi, across the Mississippi River (E), Louisiana (S), Texas and O...

Gibraltar

(Encyclopedia)Gibraltar jĭbrôlˈtər [key], British overseas territory (2015 est. pop. 34,000), 2.5 sq mi (6.5 sq km), on a narrow, rocky peninsula extending into the Mediterranean Sea from SW Spain. Most of the ...

Diggers

(Encyclopedia)Diggers, members of a small English religio-economic movement (fl. 1649–50), so called because they attempted to dig (i.e., cultivate) the wastelands. They were an offshoot of the more important gro...

Downs, North, and South Downs

(Encyclopedia)Downs, North, and South Downs, parallel ranges of chalk hills, SE England. They rise to 965 ft (294 m) at Leith Hill, Surrey. The North Downs range, extending c.100 mi (160 km) from near Farnham, Surr...