igneous concentration
21North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… …
22Cumulate rock — Cumulate rocks are igneous rocks formed by the accumulation of crystals from a magma either by settling or floating. Cumulate rocks are named according to their texture; cumulate texture is diagnostic of the conditions of formation of this group… …
23Diamond — This article is about the mineral. For the gemstone, see Diamond (gemstone). For other uses, including the shape ◊, see Diamond (disambiguation) …
24Iron ore — Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in colour from dark grey, bright yellow, deep purple, to rusty red. The iron itself is usually found in the …
25Pilot Knob (Austin, Texas) — Pilot Knob is a hill that is part of an extinct volcano located seven miles south of central Austin, Texas near Austin Bergstrom International Airport and McKinney Falls State Park.IntroductionPilot Knob is one of around 75 late Cretaceous Period …
26Egypt — /ee jipt/, n. 1. Arab Republic of. a republic in NE Africa. 64,791,891; 386,198 sq. mi. (1,000,252 sq. km). Cap.: Cairo. Arabic, Misr. Formerly (1958 71), United Arab Republic. 2. an ancient kingdom in NE Africa: divided into the Nile Delta… …
27Crystallization — Crystallizing and Crystallized redirect here. For the action adventure video game, see Crystalis. For the 2009 song by The xx, see Crystalised. For other uses, see Crystallization (disambiguation). Crystallization …
28Isochron dating — is a common technique of radiometric dating and is applied to date certain events, such as crystallization, metamorphism, shock events, and differentiation of precursor melts, in the history of rocks. Isochron dating can be further separated into …
29Geology of Mars — Mars   Mars as seen by the Hubble Space Telescope Designations …
30Roca ígnea — Rocas volcánicas en Norteamérica. R …
