152 THE SOILS OF CALVERT COUNTY 



above the Miocene in many places, consists of a medium-grained sand 

 containing small pebbles and considerable iron crust. Where these 

 different layers of sandy material have been exposed at the surface 

 through stream erosion, the various agencies of weathering, such as 

 frost, percolating rain, and organic growth, have modified the 

 originally infertile sands, so that they are capable of sustaining vege- 

 tation and have become true soils. So areas of the resulting N'orfolk 

 sand are found in the stream beds, where these layers outcrop, and over 

 the upland portion of the county where overlying materials have been 

 removed. 



This process of soil formation has occupied a long period of time; 

 and while part of the sandy material was being worked over into soil 

 where it lay, part of it was carried away by the streams and dropped 

 along the stream courses and at tide water wherever the current was 

 not swift enough to continue carrying its load of sand. The present 

 shore line lies considerably below the level of the position it occupied 

 when this action began, so that the first deposits of this transported 

 sand were in the form of terraces built far above the present mouths 

 of the streams. With the relative lowering of the water level these 

 terraces have been exposed to the agencies of the atmosphere and these 

 sands have come to form soils very similar to the ones directly derived 

 from the outcrops of the original material. Such terraces may be 

 seen near Hunting Creek bridge, along Lyons Creek, and in many 

 other localities. Part of the sand was also carried down as far as 

 the areas at present occupied by the foreland portion of the county 

 along the Patuxent Eiver, and areas of Xorfolk sand are found about 

 one mile south of Deep Landing just north of Ferry Landing. They 

 represent a terrace built by the Patuxent, in most respects similar to 

 those built by the smaller streams. 



A common peculiaritj' of all these terraces is that the sand is coarser 

 and the gravel more aboundant as one goes up stream-. This is due 

 to the diminished strength of stream currents near their mouths and 

 the consequent diminution of the size of the particles transported. 



In the northwestern part of the county and, in general, north of the 



