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RFCEIVED
<br />Map Unit Description FEB 1 62001
<br />Detailed Soil Map Units
<br />Division of ttectamatlon,
<br />~fv~t aand Safety
<br />The map units delineated on the tletailetl soil maps in a soil survey represent the soils or miscellaneous areas in the survey arAa~~hB'map unit
<br />descdptions in this report, along with the maps, can be used to determine the composition and properties of a unit.
<br />A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified
<br />and named according to the taxonomic classifcation of the dominant soils. Within a taxonomic class there are precisely defned limits for the properties
<br />of the soils. On the landscape, however, the soils are neural phenomena, and they have the charactedstic vadability of all natural phenomena. Thus,
<br />the range of some ohserved properties may extend beyond the limits defned for a taxonomic class. Areas of soils of a single taxonomic class rarely, if
<br />ever, can be mapped without including areas of other taxonomic Gasses. Consequently, every map unit is made up of the soils or miscellaneous areas
<br />forwhich it is named and some minor wmponents that belong to taxonomic Gasses other than those of the major soils.
<br />Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affeG use and management- These
<br />are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit descdption. Other minor components,
<br />however, have properties and behavioral characteristics tlivergent enough to affect use or to require different management. These are calletl
<br />conVasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small
<br />areas of strongly conVasting soils or miscellaneous areas are identifetl by a special symbol on fhe maps. The wnttasang components era mentioned in
<br />the map unit tlesuiptions. A few areas of minor components may not have been observed, and wnsequendy they are not mentioned in the
<br />descdptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and
<br />miscellaneous areas on me landscape.
<br />The presence of minor components in a map unit in no way diminishes the useWlness or accuracy of the data. The objective of mapping is riot to
<br />delineate pure taxonomic classes but rather to separate the landscape into landtonns or lantlform segments that have similar use and management
<br />requirements. The delineation of such segments on the map provides sufficient information for the development o(resource plans. If intensive use of
<br />small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas.
<br />An identifying symbol precedes the map unit name in the map unit descdptions. Each description indicates the composition of the map unit and selected
<br />properties of the components of the unit.
<br />Soils that have profiles that are almost alike make up a "soil series' Except for differences in texture of the surface layer, all the soils of a sedes have
<br />major horizons that are similar in composition, thickness, and arrangement.
<br />Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and Other characteristics that affect their use.
<br />On the basis of such differences, a soil series is divided into "soil phases." Most of the areas shown on the detailetl soil maps are phases of soil series.
<br />The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase
<br />of the Alpha sedes.
<br />Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated
<br />groups.
<br />A "complex" consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown
<br />separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6
<br />percent slopes, is an example.
<br />An "association" is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on Ne maps. Because of
<br />present or anticipated uses of the map units in the survey area, it was not consitleretl practical or necessary to map the soils or miscellaneous areas
<br />separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes,
<br />is an example.
<br />An'undifferentiated group" is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit
<br />because similar interpretations can be made for use and management. The paltem and proportion of the soils or miscellaneous areas in a mapped area
<br />are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta
<br />soils, 0 to 2 percent slopes, is an example.
<br />Some surveys include "miscellaneous areas." Such areas have little or no soil material antl support Tittle or no vegetation. Rock outcrop is an example.
<br />Additional information about the map units described in this report is available in other Soil Data Mart reports, which give properties of the soils and the
<br />limitations, capabilities, and potentials for many uses. Also, the narratives that accompany the Soil Data Mart reports define some of the properties
<br />included in the map unit descriptions.
<br />USDA N9tural ResO1RC¢S Tabular Data Version: 4
<br />Cuus¢I'FAt1O11 S¢rVIC¢ Tabular Data Version Date: 12/15/2005 Page 5 of 5
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