226 PHYSIOGRAPHY AND GEOLOGY OF THE COASTAL PLAIN PROVINCE. 



for that purpose. How extensive the bed is can only be determined by 

 boring, for no outcrops of it are seen, except along the road, but there it is 

 exposed in the ditch at the roadside for several hundred feet at least. Tests 

 of this clay (ISTo. 1356) are given in the appended table, facing page 225. 



Following the road from Fredericksburg to Stafford, there are a number 

 of indications of bluish- white Eocene clay in the ditches along the roadside 

 but most of these are topped by a heavy bed of sand. About 6 miles east 

 of north from Fredericksburg, a heavy bed of the clay is found on top of a 

 ridge. 



The section here involves: 



Feet 



Surface sand and soil 1-2 



Pink clay, laminated 12 



Whitish clay 4 



The pink clay (Lab. Xo. 1350) is distinctly stratified and in its upper 

 part contains some scattered crusts of limonite. The physical and chemical 

 properties of this clay are given in the table opposite page 225. 



The clay, although burning to a good color, is not a dense-burning one ; 

 in fact, it does not yield as tight a body as some of the Pleistocene clays. Its 

 main use should be for common brick, pressed brick, or drain tile. The 

 outcrop mentioned is somewhat distant from the railroad for cheap exploi- 

 tation, but the extension of this bed should be found to the westward, 

 nearer lines of transportation. 



The whitish clay (Lab. No. 1352), which underlies the pink clay, is of 

 buff-burning character and burns to a good body. It would no doubt make 

 a good light-colored pressed brick by either the wet method repressed, or 

 the dry-press process. Its analysis and physical tests are given in the table 

 opposite page 225. 



The Wilmont Area. 



This is practically the only locality along the Rappahannock Eiver 

 where the Pleistocene clays are worked, and the quality of those developed 

 at this point Avould make it seem desirable to prospect further for other 

 deposits. 



At the brick Avorks at Wilmont the following section is exposed : 



Feet 



Soil 1 



Blue clay ( so-called ) 5-6 



Gravelly sand (variable thickness) 6-15 



Diatomaceous earth 10 



Greensand clay 4 



