SUGGESTIONS FOK 8TDDT 239 



Where the covering of soil and other loose material is thick, 

 outcrops should be sought along the beds of rivers, creeks and 

 rivulets. Running water usually cuts through the softer material 

 and reaches the harder rock below. For this reason the gutters 

 and ditches by the sides of roads should be examined for expos- 

 ures, if no< other source of information is available. 



It is not possible here to give any adequate directions for the 

 study of soft geology. This branch is still immature and is chiefly 

 in the hands of specialists. The literature of Quaternary geology 

 is, however, very large and by a careful study of it, the beginner 

 may form some conception of its scope. A single field day with 

 a good geologist is worth more than many weeks of reading. 



FOSSILS 



It is important for the beginner to realize that perfect speci- 

 mens of fossils such as are exhibited in the museums and figured 

 in the works on palaeontology are not every where to be found 

 and that the more common examples are fragmentary. Were it 

 not for the dissolving action of atmospheric water on carbonate 

 of lime the study of fossils would still be in its infancy, as in many 

 cases the fossil is wholly inclosed in a firm mass of limestone from 

 which it can not be separated by the hammer alone. On the sur- 

 face exposures of limestone, the action of the weather removes a 

 part of the matrix, exposing for a time the surface of the shell. 

 This after a few years may in turn yield to the dissolving action 

 of atmospheric water and gradually disappear, another specimen 

 at a lower level being, gradually brought to view in its place. In 

 sandstones, the calcareous fossils are usually entirely dissolved 

 out of the surface layers and it is only by the impressions or casts 

 which they leave behind, that we know of their existence. If 

 means are afforded for excavation and blasting, below the reach 

 of the rain water, will be found a bed of rock from which the 

 calcareous matter has not been dissolved away, but in this case 

 it is often difficult to separate the fossils except by long and 

 tedious process of cleaning or developicg with small tools. 



