THE CINCINNATI QUARTERLY 



JOURNAL OF SCIENCE. 



Vol. I. APRIL, 1874. No. 2. 



The Position of the Cincinnati Group in the Geological Column of Fos- 

 siliferoits Eoeh of Noiih America. (By S. A. Miller.) 



In the early days of the science of geology, the known strata of rocks 

 were divided into systems or formations, each of which was supposed 

 to represent a great period of time, during which no great changes 

 occurred in the condition of the earth, or the animal life that inhabited 

 it. The commencement of each system or formation was supposed to 

 mark a new era of creations, and its close to represent a great cata- 

 clysm that destroyed all animal life, and effected great and wonderful 

 changes on the surface of the earth. 



Later, however, these systems and formations Avere found to be of 

 much greater depth than at first supposed, and as the science of 

 geology became better knoAvn, they were subdivided into groups, each 

 of which was found to be as distinct and marked in its character as 

 the separate systems and formations were. 



And, finally, it was found that the systems and formations were more 

 imaginary than real. That they did not mark periods of time during 

 which there was great repose on the surface of the earth, nor were 

 they ushered in with special creations of organic life, nor closed with 

 violent cataclysms that destroyed every living thing. On the contrary, 

 as the examinations and discoveries began to perfect the geological col- 

 umn, and paleontology became a science, it was ascertained that the 

 special evidences of creations, and cataclysms were missing, and that 

 the never ceasing change which now takes place is the only criterion 

 by which to judge of the changes in the past. 



