MARYLAND GEOLOGICAL SURVEY 149 



on the geology of the county. This layer of material at one time 

 formed an almost continuous sheet over all the upland part of the 

 county, and when first built into the land area of the region it was 

 covered by other sediments which have since been removed by erosion. 

 The remaining portions of these other sediments constitute the iSTorfolk 

 and Leonard town loam areas which still exist, surrounded by bands 

 or areas of the Windsor sand at the present time. In many instances 

 it is still possible to trace the sands and gravels of this soil t}'pe to 

 the edge of Norfolk or Tjconarcltown loam areas and then to observe 

 their continuation under the heavier materials of those types. This 

 fact is conclusive evidence in itself of the origin of the type, but the 

 location of the type between stream heads and along divides, where 

 erosion has been most active, and its general presence immediately 

 over Miocene strata throughout the entire area corroborate the more 

 direct evidence. The close similaritv of the materials of the soil to 

 those of the orange-sand and gravel — in many cases amounting to 

 complete identity — also supports this explanation of the origin of the 

 type; that is, a definite layer of sedimentary materials has been exposed 

 by erosion to form a definite soil type. This is not the only case to 

 be found in tlie county, as is indicated under the discussion of the 

 Norfolk sand and the Sassafras loam. 



One marked feature of the Windsor sand area is the absence of 

 surface streams. The incoherence and porosity of the soil allow the 

 water falling on its surface to sink immediately to considerable depths, 

 and the flow of water takes place as a gradual seepage along the surface 

 of sliohtlv more dense materials Ivino- under the sand and gravel of this 

 soil. 



As a result stream channels are only sparingly present in the area, 

 for absence of surface flow prevents the formation of stream ways and 

 the small washes formed by the most torrential storms are rapidly 

 obliterated by the crumbling of incoherent margins or by the ordinary 

 operations of cutivation. 



The soil proper of the Windsor sand areas consists of a medium 

 to a coarse-grained sand, usually containing considerable quantities of 



