102 TEANSACTIONS OF THE [1809 



is a body of coarse, irregular sands and greensand, loaded with 

 snuif-like sand and atoms of clay, becoming indurated as it 

 ascends. It holds a small proportion of fine gravel, especially 

 next the bottom, and its upper portion is usually consolidated 

 into hard sandrock. In the coarser parts of this sandrock 

 fossils are seldom found, but in the finer and more clayey por- 

 tions fossil shells, or their casts and moulds, often occur in 

 large numbers. 



This structural unit is unconformable with the upper mem- 

 ber of the Cretaceous Marl system, upon which it rests in great 

 part, but it is generally hard to mark the line of separation 

 between the two, because of the similarity of their elements 

 along the line of contact. Wherever the loose marl sands of 

 the two members are brought in contact they mix together and 

 no break is distinguishable ; but where induration is present in 

 either, the line of demarcation can be distinguished by careful 

 examination. 



The Eocene sandrock and the sand resulting from its disin- 

 tegration is, however, by no means confined to the surface of 

 the Middle Marl bed. It extends farther inland than that 

 member, rests upon other members of the Cretaceous, and near 

 its inner thin edge lies upon Albirupean sands, and attests its 

 identity by holding typical Eocene fossil shells. 



Much of the ferruginous sandrock of the region east of Curtis 

 Creek, which we had previously regarded as of Quaternary 

 origin, has, by close inspection, been found to hold fossil casts 

 of Eocene type. Accordingly, it would appear that at length 

 we are justified in referring all the sandrock of this pattern, now 

 in place upon the hills of this part of the Albirupean region, to 

 the Eocene period. Even in localities where this sandrock 

 abounds in fossil shells there are large and continuous beds of 

 it in which no fossils can be found. 



The greatest thickness attained by the Eocene of the territory 

 represented by the diagram is thirty feet. It is of about that 

 thickness on Mount Misery, and is there remarkable for being 

 loaded with broken and chiefly angular pieces of the ferruginous 

 sandrock, packed in close aggregations in many parts of the bed. 



The fact yet remains to be explained how it came to pass that 

 sheets of this stone, ranging from two feet to only two or three 



