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rock

(Encyclopedia)rock, aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their o...

rock garden

(Encyclopedia)rock garden, garden planned around natural rock formations or rocks artificially arranged to simulate natural (often mountainous) conditions. The concept of rock gardens is believed to have been intro...

rock music

(Encyclopedia)rock music, type of music originating in the United States in the mid-1950s and increasingly popular throughout much of the world. A turning point in rock music occurred in the mid-1970s in the ...

igneous rock

(Encyclopedia)igneous rock: see rock.

sedimentary rock

(Encyclopedia)sedimentary rock: see rock; sediment. ...

Little Rock

(Encyclopedia)Little Rock, city (1990 pop. 175,795), state capital and seat of Pulaski co., central Ark., on the Arkansas River; inc. 1831. It is a river port and the administrative, commercial, transportation, and...

Starved Rock

(Encyclopedia)Starved Rock, cliff, 140 ft (43 m) high, overlooking the Illinois River between La Salle and Ottawa, N Ill. Legend says that in the 18th cent. the Ottawas drove a band of Illinois onto the cliff, wher...

Percé Rock

(Encyclopedia)Percé Rock pĕrsāˈ [key], E Que., Canada, just off the tip of the Gaspé Peninsula. It is a massive rock (1,420 ft/433 m long; c.300 ft/90 m wide; and 290 ft/88 m at the highest point), rising shee...

rock crawler

(Encyclopedia)rock crawler, name applied to the slender, wingless insects of the family Grylloblattidae in the order Orthoptera. They have long antennae and range in length from 1⁄2 to 1 in. (15–30 mm). Rock cr...

Rock Falls

(Encyclopedia)Rock Falls, city (1990 pop. 9,654), Whiteside co., NW Ill., on the Rock River opposite Sterling; inc. 1867. It is an industrial center in a farm region with corn, soybeans, cattle, and hogs. Electroni...