SEVENTH GEOLOGICAL EPOCH. 



The study of the creta'ceous rocks brings us, as it were, to the 

 .ermination of that period in the history of the earth's structure to 

 which the character of antiquity belongs, hi the succeeding 

 period, we shall find all the fossils are either resemblances or types 

 of existing organic creatures. 



LESSON V. 



SEVENTH GEOLOGICAL EPOCH. Tertiary Formation Eocene 

 b eas Paris Basin Fossils Jinoplothe'rium Pakothe'rium 

 Miocene beds Dinothe 'rium Lignites Pliocene beds 

 Fossils Bone Caverns. 



SUPERFICIAL DEPOSITS. Drift Diluvium Megathe'rium 

 Boulder Formation diluvium Big Bone Lick. 



EIGHTH GEOLOGICAL EPOCH. Modern Formation. 



SEVENTH GEOLOGICAL EPOCH. 

 TERTIARY FORMATION. 



1. Ordinarily, geologists. designate under the collective name of 

 SECONDARY FORMATION, the long series of systems of rocks, com- 

 mencing above the transition formation with old red sandstone and 

 coal ( fig. 146), and terminating above with the chalk ; and they 

 give the name of TERTIARY FORMATION to those strata which are 

 more recent than the chalk, and consequently superior to it. but 

 still more ancient than the strata of the present or modern epoch. 



2. During that period the seas were very much less extensive 

 than they were in the more remote geological ages, and conse- 

 quently the sedimentary deposits formed in those waters are of less 

 extent and more isolated. Moreover, their formation was effected 

 at different points of the globe, and at different periods, and to fol- 

 low their history in chronological order, it is necessary to subdivide 

 them into three groups. At the period contemporaneous with the 

 deposit of each one of these series of formations, there existed 

 particular species of organized creatures, mingled with other spe- 

 ( ies like the preceding or succeeding periods ; but the fauna of all 

 the divisions of this period possesses certain common characters, 

 and among the most remarkable of these is the existence of a 

 great number of mammals. 



1. What is understood by secondary formation? What is meant by tei- 

 tiary formation? 



2. How did the seas of the tertiary epoch differ from those of more re- 

 mote geological ages ? What is the most remarkable characteristic qf the 

 tertiary formation ? 



