MARYLAND GEOLOGICAL SURVEY 235 



tion, but are improved, well kept, and indicate a generally prosperous 

 condition. 



CECIL MICA LOAM. 



Like the formation just described, the Cecil mica loam also occu- 

 pies an area in the rolling uplands of the Piedmont Plateau. There 

 is but one occurrence of this formation in Cecil county, and that is 

 along the northern border in the eastern part, where Maryland comes 

 in contact with Pennsylvania on its northern border. This area, is 

 nearly 10 miles in length, and from 1 to 2 miles in width. The 

 surface is rough and broken along Big and Little Elk and Christiana 

 creeks; otherwise it is level or gently rolling. The uplands may 

 rise from 200 to slightly over 400 feet in elevation. 



The soils are also residual, having been derived from the decom- 

 position of gneiss and schist, which contain, among other rock form- 

 ing materials, large quantities of mica. In the soils this mica appears 

 in broken fragments, from the tiniest bits to particles of over a half 

 inch in diameter. It is so abundant as to make the soils fairly sparkle 

 in the sunlight, and on the soft dirt roads it floats away in the breeze 

 with other dust particles. This feature has given the name to the 

 soils, and they are commonly referred to as the red and white isin- 

 glass lands. The soils of this formation are light loams, lighter in 

 texture than the Cecil loam, and they generally have a brownish or 

 yellowish-brown color. They contain considerable sand, but are 

 mostly composed of silt with small amounts of clay. The subsoils, 

 from a depth of 10 to 30 inches, consist of reddish-yellow clay loam, 

 which also contains a large percentage of finely divided mica of the 

 muscovite variety. In texture the subsoils differ little from the 

 soils, although they may contain a slightly increased percentage of 

 silt, At an average depth of 30 inches the subsoils grade into the 

 loose, decomposed gneiss, granite, schist, or whatever rock the soil 

 is derived from. These soils are always warm and dry, and possess 

 excellent underdrainage. 



The mechanical analyses of typical soils and subsoils are given in 

 the table following: 



