418 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 16, 



lowest of these is a mass of red clay, very hard and tenacious, and 

 containing large rounded boulders often grooved and striated. This 

 bed thus corresponds with the great Drift or Boulder Clay deposit in 

 other parts of Scotland. On it rest thick shingle-banks, composed 

 of layers of sand, gravel, and well-rounded stones of various sizes. 

 On these stones no grooves or striae were seen, but they closely re- 

 semble the waterworn stones on the shore of the sea. The boulder 

 clay in some places rises into low hills ; the shingle-deposits rather 

 form banks or terraces, of which three or four at different elevations 

 may occasionally be traced. In the hollows between these hills and 

 banks large deposits of peat, associated with fine clays and sands, 

 have been formed. Sections of the upper portions of these forma- 

 tions are often well exposed in the banks of the stream that drains 

 this valley. 



Fig. 3. — Section in the Moss neai' Backs. 





inches. 



«. Soil 12 to 14 



6. Brownish-red clay 12 



c. Deep red ferruginous clay. . 12 



inches. 



d. White clay 8 to 10 



e. Peat, with trees 10 — 20 



/. Red clay 24 — 36 



Fig. 3 is one of these sections, presenting some curious peculiari- 

 ties. The lowest bed /is a red clay, but different in character from 

 the inferior boulder clay. Only from 2 to 3 feet thickness of this 

 was seen, but the bed is probably deeper. On it follows a bed of 

 peat with numerous roots and branches of trees. In some places the 

 roots seemed to have sunk into the red clay, and there the peat was 

 also deeper. On this followed a bed of white clay, in one place 

 entirely cutting off the peat, as shown in the section. Above this 

 was 1 2 inches of deep red ferruginous clay, then as much of brownish 

 red clay, and the whole covered by about 12 or 14 inches of soil. 



The two following sections (figs. 4 & 5), of which the details are 

 subjoined, will show the variations to which these deposits are liable, 

 though some of the beds, as the peat-bed marked e, with d, c, and b, 

 seem very constant over a considerable extent of surface. The wood 



