marl, or of the Columbian clayey loam, already described as 

 overlying the Wilcox and Loess regions. 



All the southern half of the State, south of the Jackson 

 prairie belt, consists of a maturely dissected plain gently sloping 

 to the Gulf. The relief to within twenty or thirty miles of the 

 Gulf coast is considerable, some of the hills being 150 feet or more 

 above the valleys, and the aspect presented in many parts is de- 

 cidedly hilly and rough. The red sands of the Lafayette forms 

 the surface soil over large areas east of the Illinois Central 

 Railroad, the red clay loam overlying this in most of the region 

 lying west of that road. The underlying formation over the whole 

 area is the Grand Gulf, of alternating sands and clays. 



In the light of this brief study of the geological formations 

 of the State we would be led to infer from their character and 

 arrangement that, on the whole, erosion would be most active in 

 the broad central belt of north Mississippi corresponding to the 

 outcrop of the Wilcox Formation. It is most active here because 

 the region is one of considerable elevation and of decided slopes 

 hilly; the soil is sandy, or underlaid by sand, which becomes ex- 

 posed on the slopes and permits undercutting; the rainfall is 

 heavy as elsewhere in the State; the timber has been very 

 largely removed, and much of the surface lies out in old fields. 

 Erosion is hardly ever seen in the wooded parts, and then only 

 by invasion from bordering fields, or after thinning of the forest 

 has destroyed the natural balance in conditions under which the 

 original slopes were developed. Confirmation of these state- 

 ments can be found anywhere in that region. 



The southern section of the State has such a large proportion 

 of sand in the soil and surface formations that erosion progresses 

 rapidly if unchecked, and over much of the surface washing of 

 the lands is prominently developed. 



The Loess or Bluff Hills present some of the most striking 

 erosion features to be seen in the State. Great "gulfs" or chasms 

 with vertical walls dissect the uplands in places, though the 



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