SOILS AND LANDFORMS 



INTRODUCTION 



This atlas topic deals with the natural phenomena of soils, landforms, 

 and related subjects, which includes regional surface landforms, soils, beach 

 erosion and accretion areas, faults, high-energy beaches, and active dunes. 



This narrative supplements the atlas maps by explaining not only how and 

 where environmental conditions currently exist but also how they have 

 appeared or evolved in the past. The information is relevant to decision- 

 makers charged with duties ranging from preservation and conservation to 

 responsible, economically feasible land and resource development. 



REGIONAL SOILS AND LANDFORMS 



The most detailed soil classification is the soil phase. A soil phase is 

 a subdivision of a soil series based on differences that affect management of 

 that subdivision. A soil series may be divided into phases on the basis of 

 differences in slope, thickness (depth), stoniness, or any other characteris- 

 tic that affects its usage. An example of a soil phase would be "Troup loamy 

 sand, 5% to 8% slopes." 



Groups of soils derived from similar parent material and similar in 

 vertical profile characteristics and arrangement are called soil series. 

 Soils within a series may have some variation in the texture of the surface 

 horizon (layer), but are similar to one another in color, structure, 

 reaction, chemical composition, and overall consistency. 



A group of soil series that is found in the same geographical area and 

 generally occurs in a characteristic pattern is called a soil association. 

 For example, the Izagora-Bethera-Suf fol k soil association (map unit 13) is 

 where Izagora soils are found on higher, flatter areas; Bethera soils are 

 found in the depressions and drainage ways, and Suffolk soils are found on 

 the slopes connecting the two. These associations are usually defined and 

 delineated as a single map unit, and are the basic units dealt with in this 

 atlas. Although most of the areas in an association are composed of major 

 soil series, there are a number of other soil series within the association 

 which are less common; these are called minor soils. 



The soil association maps available in the soil surveys of Mobile 

 (Hickman and Owens 1980) and Baldwin (McBride and Burgess 1964) Counties are 

 at 1:316,800 scale, (1 cm = 3.2 km, 1 inch = 5 mi). This information 



was transferred to the 1:100,000 (1 cm = 1 km, 1 inch = 1.6 mi) scale 



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