CLASSIFICATION OF FORMATIONS. 



Fig. 291. Fig. 292. 



Examples of rocks cut and fashioned by water. 



think that currents and waves cannot act effectively until the soil has been 

 previously prepared by the fissures or deteriorations caused in rocks by 

 movements of the earth. 



We must not confound with divisions produced by water certain accidents 

 which may result from shrinking produced by metamorphism. This pro- 

 bably takes place in dolomites, which follow compact limestone in a great 

 many places, as in the Tyrol and in Cevennes. Masses of these matters 

 are frequently split and slashed in all directions on the surface, particularly 

 on the summits of mountains or on plateaux, very nearly in the same way 

 that calcareous deposits are cut by water. Now, the change from a simple 

 to a double carbonate, specifically heavier, requires contraction in masses 

 submitted to dolomisa'tion ; therefore, the latter must be split and cracked 

 in all directions, and the denudations they present are consequences of 

 these effects. 



LESSON X. 



Classification of Formations Different kinds of Stratification 

 Dip Strike Conformable Stratification Un conformable 

 Stratification False Stratification The form and habits of 

 an Animal deducible from a single bone Relative ages of the 

 principal catastrophes of the Globe Systems of Upheaval 

 Classification of State of Europe at different epochs of forma- 

 tion Deluge Geogeny. 



Classification of Formations. 



1. As already mentioned, the several formations are divided into 

 two Classes, namely : 



1st. Massive, or igneous formations, which are produced by the 



1. How are the several formations divided ? What are the divisions ? 

 16 



f ^ or THE 



