the Eai^tfis Contraction from Cooling. 51 



sources of the elevation that takes place during the making of 

 geosynclinal monogenetic mountains. 



And the statement of Professor Hall may be made right if we 

 recognize the same distinction, and also reverse the order and 

 causal relation of the two events, accumulation and subsidence ; 

 and so make it read : — 



Regions of monogenetic mountains were, previously and pre- 

 paratory to the making of the mountains, areas each of a slowly 

 progressing geosynclinal, and consequently of thick accumula- 

 tions of sediments. 



The prominence and importance in orography of the moun- 

 tain individualities described above as originating through a 

 geosynclinal make it desirable that they should have a distinc- 

 tive name ; and I therefore propose to call a mountain-range of 

 this kind a synclinorium, from synclinal and the Greek opos, 

 mountain. 



This brings us to another important distinction in orographic 

 geology, that of a second kind of monogenetic mountain. The 

 synclinoria were made through a progressing geosynclinal. Those 

 of the second kind, here referred to, were produced by a progress- 

 ing geanticlinal. They are simply the upward bendings in the 

 oscillations of the earth's crust, the geanticlinal waves, and 

 hardly require a special name. Yet, if one is desired, the term 

 anticlinorium, the correlate of synclinorium, would be appro- 

 priate. Many of them have disappeared in the course of the 

 oscillations ; and yet some may have been for a time, perhaps 

 millions of years, respectable mountains. The " Cincinnati 

 uplift/' extending southwestward from southern Ohio (about 

 Cincinnati) into Tennessee, and referred by Newberry and 

 others to the close of the Lower Silurian, was made at the same 

 time, or nearly, with the Green Mountains ; but while the latter 

 range is a synclinorium, the former is a geanticlinal or an anti- 

 clinorium, and it is one of the few (probably few) permanent 

 monogenetic elevations of this kind over the earth's surface. 

 There may possibly have been crumpling or crushing in the 

 deep-seated rocks below, which determined its permanence. As 

 far as the Palaeozoic rocks constituting it go, it is a simple syn- 

 clinal ; but it is really a synclinal of the earth's crust, and hence 

 wholly distinct from ordinary synclinals, or those subordinate 

 among the plications in a synclinorium, like the synclinals of the 

 Alleghanies. 



The geosynclinal ranges or synclinoria have experienced in 

 almost all cases since their completion true elevation through 

 great geanticlinal movements, but movements that embraced a 

 wider range of crust than that concerned in the preceding geo- 

 synclinal movements, indeed a range of crust that comes strictly 



E 2 



