DESCRIPTION OF THE DEPOSITS 



311 



coarser gravel intervening, as in plate 12, figure 1, and plate 13, figure 1. 

 This coarser gravel is the top member of the lower sand-gravel formation. 

 The contact as seen here is very sharp ; the cobbles of the lower two feet 

 are embedded in fine sand, or else porous and covered with a film of clay. 

 In most sections the contact is not so sharp as here, although as a rule 

 there is clearly a lower finer member and an upper coarser member. This 



FiGiRE 1. — ToiJOfjiaphia Mai) of the Area under Discussion 



Letters indicate localities where tlie more important photographs were taken ; numbers 

 indicate localities where fossils were found, as well as photographs taken 



gravel gives the impression of being light brown in color. Tlie gravel 

 dealers generally speak of it as light gravel, as opposed to the lower deposit, 

 which they call dark. The gravel is rounded to subangular and shows 

 no striations, so far as observed. Stratification is not distinct except 

 when viewed in sections transverse to the esker, when it is fairly evident. 

 The chief feature which needs to be explained in regard to the lower 

 sands and gravels is the change in coarseness from top to bottom, the 



