Transition horizon

O class 1 - topsoil with high anthropogenic heavy metal pollution 0-20 cm class 2 - horizon with extremely high copper pollution 20-35 cm V class 3 - transition horizon with rapidly decreasing heavy metal concentrations ... 

Chernozem. A soil consisting of a black or nearly black, organic-rich A horizon, high in exchangeable calcium, underlain by a lighter-colored transitional horizon above a layer of calcium carbonate accumulation occurs in a cool subhumid climate under tall and midgrass prairie vegetation. 

The B horizon is commonly referred to as subsoil , consists of mineral layers which may contain concentrations of clay or minerals such as iron or aluminium oxides. This layer is also known as the zone of accumulation . Plant roots penetrate through this layer, but it has very little humus. It is usually brownish or red because of the clay and iron oxides washed down from A horizon. The B horizon may be divided into B1, B2 and B3 types. B1 is a transitional horizon to an A3 containing some A-horizon characteristics. B2 horizons have a concentration of clay, minerals, or organic debris. B3 horizons are transitional between the overlying B layers and materials of whether C or D horizons beneath it. This layer is little affected by soil forming processes. The C horizon may contain lumps or more likely large shelves of unweathered rock. The C horizon also contains parent material. 

Transitional horizons are layers of the soil between two master horizons. The designation uses the capital letters of the two master horizons the first letter indicates the dominant master horizon characteristics while the second letter indicated the subordinate characteristics. For instance, an AB horizon indicates a transitional horizon between the A and B horizon, but one that is more like the A horizon than the B horizon. An AB or BA designation can be used as a surface horizon if the master A horizon is believed to have been removed by erosion. The separate components of two master horizons are recognizable in the horizon and at least one of the component materials is surrounded by the others. The designation is by two capital letters with a slash between them. The first letter designates the material of greatest volume in the transitional horizon. For example A/B, B/A, E/B or B/E. 

Demand patterns can also vary significantly ranging from cases where due dates must be obeyed to cases where production targets must be met over a time horizon (fixed or minimum). Changeovers are also a very important factor, which is particularly critical in cases of transitions that are sequence dependent on the products, as opposed to simple setups that are only unit dependent. 

Transition to B, more like A than B Transition to A, more like B than A Horizon usually enriched in silicate clays, or Fe,... 

Contrarily to the flatness and horizon problem which have a very similar origin, the unwanted relic problem comes from a very different cause. During the expansion, the Universe becomes colder because of the redshift that radiation experiences. It can happen that during this cooling phase, some phase transition occur, during which some stable objects called topological defects are created. 

Sampson, Steven. 1995. All Is Possible, Nothing Is Certain The Horizons of Transition in a Romanian Village. In East European Communities The Struggle for Balance in Turbulent Times, edited by David Kideckel, 159-76. Boulder, CO Westview Press. 

Fig. 12. Petrochemical characteristics of the BIF and associated schists of the Middle suite of the Krivoy Rog group (relationship of AFM ratios) I = hematite and hematite-magnetite rocks 2 = magnetite, siderite-magnetite, and silicate-magnetite rocks 3 = transitional strata, schist intercalations in layers (horizons) of BIF 4 = various schists constituting schist layers (horizons) (Mel nik, 1975).

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