sediments of volcanic origin
21eastern Africa — ▪ region, Africa Introduction part of sub Saharan Africa comprising two traditionally recognized regions: East Africa, made up of Kenya, Tanzania, and Uganda; and the Horn of Africa, made up of Somalia, Djibouti, Eritrea, and Ethiopia.… …
22Colombia — Colombian, adj., n. /keuh lum bee euh/; Sp. /kaw lawm byah/, n. a republic in NW South America. 37,418,290; 439,828 sq. mi. (1,139,155 sq. km). Cap.: Bogotá. * * * Colombia Introduction Colombia Background: Colombia was one of the three countries …
23Holocene Epoch — formerly Recent Epoch Latest interval of the Earth s geologic history, dating from 10,000 years ago to the present. The younger of the two epochs that constitute the Quaternary Period, the Holocene follows the last glacial stage of the… …
24Marcellus Formation — Stratigraphic range: Middle Devonian …
25Spain — /spayn/, n. a kingdom in SW Europe. Including the Balearic and Canary islands, 39,244,195; 194,988 sq. mi. (505,019 sq. km). Cap.: Madrid. Spanish, España. * * * Spain Introduction Spain Background: Spain s powerful world empire of the 16th and… …
26Tuff — (from the Italian tufo ) is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff should not be confused with tufa , another type of rock. Volcanic ashThe products of a volcanic eruption are… …
27Hydrothermal vent — Marine habitats White smokers emitting liquid carbon dioxide at the Champagne vent, Northwest Eifuku volcano, Marianas Trench Marine National Monument Littoral zone …
28Geology of solar terrestrial planets — The geology of solar terrestrial planet mainly deals with the geological aspects of four planets of the Solar system namely, Mercury, Venus, Earth and Mars and one terrestrial dwarf planet, Ceres. Objects like Pluto are similar to terrestrial… …
29Madagascar — Madagascan, n., adj. /mad euh gas keuhr/, n. an island republic in the Indian Ocean, about 240 mi. (385 km) off the SE coast of Africa: formerly a French colony; gained independence 1960. 14,061,627; 227,800 sq. mi. (590,000 sq. km). Cap.:… …
30Geology of the Pacific Northwest — The geology of the Pacific Northwest refers to the study of the composition (including rock, minerals, and soils), structure, physical properties and the processes that shape the Pacific Northwest region of the United States and Canada. The… …
