igneous concentration
51Fractional crystallization (geology) — Crystallization Concepts …
52Boninite — is a mafic extrusive rock high in both magnesium and silica, formed in fore arc environments, typically during the early stages of subduction. The rock is named for its occurrence in the Izu Bonin arc south of Japan. It is characterized by… …
53coal mining — Coal was very important in the economic development of Britain. It was used as fuel in the factories built during the Industrial Revolution and continued to be important until the 1980s. The main coalfields are in north east England, the north… …
54Europe — /yoor euhp, yerr / for 1; /yoo roh pee, yeuh / for 2, n. 1. a continent in the W part of the landmass lying between the Atlantic and Pacific oceans, separated from Asia by the Ural Mountains on the E and the Caucasus Mountains and the Black and… …
55volcano — /vol kay noh/, n., pl. volcanoes, volcanos. 1. a vent in the earth s crust through which lava, steam, ashes, etc., are expelled, either continuously or at irregular intervals. 2. a mountain or hill, usually having a cuplike crater at the summit,… …
56Archean Eon — or Archaean Eon or Archeozoic Eon Older of the two divisions of Precambrian time. The Archean begins with the formation of the Earth s crust с 3.8 billion years ago and extends to с 2.5 billion years ago, up to the start of the Proterozoic Eon,… …
57Geography of Singapore — Singapore is a small, heavily urbanised, island city state in Southeast Asia, located at the southern tip of the Malayan Peninsula between Malaysia and Indonesia. Singapore has a total land area of 778 km² and 193 km of coastline. It is …
58Boninit — ist ein mafisches vulkanisches Gestein, das als primitiver Andesit angesehen wird. Es tritt als extrusives Gestein mit hohem Gehalt an Magnesium und Silizium in Forearc Becken auf, typischerweise in den Frühstadien von Subduktionsprozessen.… …
59Water purification — This article is about large scale, municipal water purification. For portable/emergency water purification, see portable water purification. For industrial water purification, see deionized water. For distilled water, see distilled water. Water… …
60Trophic state index — The quantities of nitrogen, phosphorus, and other biologically useful nutrients are the primary determinants of a body of water s trophic state index (TSI). Nutrients such as nitrogen and phosphorus tend to be limiting resources in standing water …
