BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 6, pp. 55-70 December 17, 1894 



THE EXTENSION 6f UNTFOinriTARTANISM TO DEFOR- 

 MATION 



BY W J MCGEE 



{Read before the Society August 14, 1S94) 



CONTENTS 



Page 



The known movements of the earthcrust 55 



Observed movements 55 



ISIovements inferred from shorehnes 57 



Movements inferrcHl from later formations and nnconformities 58 



Movements inferred from the continents 00 



Essential characters of earth movements 61 



Methods of acquiring: knowledge 62 



The empiric method 62 



The scientific method 64 



Growth of knowledge of the earthcrust . 65 



The stage of speculation 65 



The stage of ratiocination 66 



The stage of genetic classification 66 



The heritage of hypothesis 67 



The meaning of the movements 69 



The known Movements of the Earthcrust. 



observed movements. 



Holland is sinking with respect to sealevel and the ocean is encroach- 

 ing on its shores. Dikes are Ijuilt to protect the land, and from genera- 

 tion to generation they have ])een i-aiscsd higher and higher until now 

 fields and meadows lie five or ten yards helow tlie level of the ocean. 

 The sinking has i)rogressed varia)))}', yet without comi)lete interruption, 

 since the l)eginning of local history, and the measurements of a tliousand 

 years indicate that it ranges from 0.09 to 0.75 of a meter i)er century, the 

 more exact measurements since 1732 giving a mean of 0.20 of a meter 

 for each hundred years. No horizontal movement of the terrestrial crust 

 has heen detected in connection witli this vertical movement. 



IX -Bull. Geql. Soc. Am., Vol. 0, 1894. (55) 



