/strat'euh fi kay"sheuhn/, n.1. the act or an instance of stratifying.2. a stratified state or appearance: the stratification of ancient ruins from eight different periods.3. Sociol. the hierarchical or vertical division of society according to rank, caste, or class: stratification of feudal society.4. Geol.a. formation of strata; deposition or occurrence in strata.b. a stratum.[1610-20; < ML stratification- (s. of stratificatio). See STRATI-, -FICATION]
* * *Layering that occurs in most sedimentary rocks and in igneous rocks that are formed at the Earth's surface, such as from lava flows and volcanic deposits.The layers (strata) may range from thin sheets that cover many square miles to thick lenslike bodies that are only a few feet wide.
* * *▪ geologythe layering that occurs in most sedimentary rocks and in those igneous rocks (igneous rock) formed at the Earth's surface, as from lava flows and volcanic fragmental deposits. The layers range from several millimetres to many metres in thickness and vary greatly in shape. Strata may range from thin sheets that cover many square kilometres to thick lenslike bodies that extend only a few metres laterally.Planes of parting, or separation between individual rock layers, are termed stratification planes. They are horizontal where sediments are deposited as flat-lying layers, and they exhibit inclination where the depositional site was a sloping surface. The bottom surface of a stratum roughly conforms to irregularities of the underlying surface; the stratification plane above the stratum, however, tends to be nearly horizontal.Stratification in sedimentary rocks may result from changes in texture or composition during deposition; it also may result from pauses in deposition that allow the older deposits to undergo changes before additional sediments cover them. A sequence of strata, therefore, may appear as alternations of coarse and fine particles, as a series of colour changes resulting from differences in mineral composition, or merely as layers of similar aspect separated by distinct planes of parting. No direct relationship exists between the thickness and extent of strata and the rate of deposition or the time represented; for example, a stratum of limestone 2.5 cm (1 inch) thick may take longer to form than a stratum of sandstone 3 m (10 feet) in thickness. The most common cause of stratification is variation in the transporting ability of the depositing agent. Water and wind sort sediments according to size, weight, and shape of particles, and these sediments settle in layers of relative homogeneity. Differences in sediment composition resulting from different sources, and variation in sediment brought about by change in agents of deposition, also lead to stratification.Where layers have been deformed, the record of past movements of the Earth's surface is preserved in the stratification, making possible the interpretation of geologic events and permitting such practical results as the location of mineral deposits, petroleum fields, and groundwater reservoirs.Stratification in sedimentary rocks varies greatly both in degree of prominence and in details of structure. In general, it is best developed in fine-grained sediments and is least apparent and least persistent in coarse-grained materials such as conglomerates. Two important and distinctive structural types are recognized as characteristic of particular environments. These are cross-bedding, which is common in fluvial or eolian deposits, and graded bedding, which reflects transport by density (or turbidity) currents or, in certain cases, varved deposits.Stratification in volcanic rocks (extrusive rock) differs in some respects from that in sedimentary rocks. Fragmental volcanic material becomes sorted in flight under the influence of gravity, particle size, and wind. Falling to the ground, it may form well-sorted layers. If it falls into lakes or the sea, it becomes layered like any other waterborne detrital matter. Stratification also may result from successive flows of liquid lava or alternations between flows and ashfalls.Not all sedimentary deposits are stratified. Those transported by ice alone, landslide deposits, and residual soils, for example, exhibit no stratification. Original stratification may be destroyed by plants or animals, by recrystallization of limestones, or by other disturbances subsequent to deposition.
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stratification — [ stratifikasjɔ̃ ] n. f. • 1620 chim.; lat. des alchim. stratificatio, onis 1 ♦ Géol. Disposition des matériaux par strates (dans les terrains sédimentaires); processus géologique par lequel les matériaux se sont ainsi disposés. Stratification… … Encyclopédie Universelle
Stratification — is the building up of layers, and can have several meanings *Social stratification, is the dividing of a society into levels based on wealth or power. *Stratification in archaeology is the formation of layers (strata) in which objects are found.… … Wikipedia
Stratification — Strat i*fi*ca tion, n. [Cf. F. stratification.] 1. The act or process of laying in strata, or the state of being laid in the form of strata, or layers. [1913 Webster] 2. (Physiol.) The deposition of material in successive layers in the growth of… … The Collaborative International Dictionary of English
Stratification — (v. lat.), Schichtung, Aufschichtung … Pierer's Universal-Lexikon
stratification — index order (arrangement) Burton s Legal Thesaurus. William C. Burton. 2006 … Law dictionary
stratification — (n.) 1610s, from Mod.L. stratificationem (nom. stratificatio), noun of action from pp. stem of stratificare to form strata, from stratum thing spread out + root of facere to make (see FACTITIOUS (Cf. factitious)) … Etymology dictionary
stratification — [strat΄ə fi kā′shən] n. 1. the process of stratifying or the state of being stratified 2. a stratified arrangement or appearance 3. Geol. a structure characterized by a succession of tabular layers, beds, strata, etc. stratificational adj … English World dictionary
stratification — The term stratification in sociology is usually applied to studies of structured social inequality ; that is, studies of any systematic inequalities between groups of people, which arise as the unintended consequence of social processes and… … Dictionary of sociology
Stratification — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. En botanique, la stratification est l opération qui consiste à lever la dormance. En géologie, la stratigraphie étudie la disposition des roches en… … Wikipédia en Français
stratification — by Kylie Message Deleuze and Guattari explain stratification is an ongoing, rhizomatic process that contributes to the line of emergence or becoming. This process may (or may not) lead to our rejection of a unifying subjectivity and embrace… … The Deleuze dictionary