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The Sand Areas of Indiana. 



By Chas. W. Shannon. 



Sand deposits may be studied from two points of view, tirst as to 

 origin and structure, second as to their economic value. Dune sand Is a 

 kind of soil and at the same time is a particular kind of deposit. 



The sand areas of Indiana consist of sand-dunes, sand-hills, sand- 

 flats or "swales" and sand prairies. The pricipal areas of the sand de- 

 ]josits are. (1) The dunes and ridges about the head of Lake Michigan. 

 (2) The great expanse of the sand-hills and plains to the south of the 

 principal dune area, extending to the southern limit of the marshy area 

 south of the Kankakee River and east to the gravelly moraines. (3) 

 The sand prairies of the lower Wabash Valley. (4) The deposits along 

 the Ohio River. (5) The deposits along White River and its tributaries. 



Tlie Dune Area. — One of the marked features of the northern part 

 of the State is the shifting dunes and ridges of sand. These great tracts 

 of sand about the head of Lake Michigan belong wholly to beach ac- 

 cumulations, being sand derived from the immediate south shore, and 

 from the erosion of the eastern and western shores and carried south- 

 ward by shore currents during northern gales, and after being rolled upon 

 the south shore it is carried inland by the winds and built up into unstable 

 hillocks and ridges. 



"Dune sand consists of loose, incoherent sand forming hillocks, rounded 

 hills and ridges of various heights. Dunes are found along the shores 

 of lakes, rivers or oceans, and in desert areas. They are usually of 

 little value in their natural condition because of their irregular surface, 

 the loose open nature of the material, and its low water holding capacity. 

 Dunes are frequently unstable and drift from place to place. The con- 

 trol of these dunes by the use of windbreaks and binding grasses is fre- 

 quently necessary, as at Cape Cod and on the coast of California, for 

 the protection of adjoining agricultural lands. In certain regions they 

 have been improved for agricultural purposes or employed as catchment 

 areas in city water supplies or planted to pine forests for the protection 

 of agricultural lands and for revenue." — U. S. Bureau Soils. 



