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THE 



AMERICAN JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



Art. XXXII. — On the Crumpling of the Earth's Crust;* by 

 William B. Taylor. 



The causes and conditions of the vast series of movements 

 which have taken place throughout the earth's crust, present 

 perhaps the most fundamental problem of physical or dynam- 

 ical geology. And yet this problem is one of the most diffi- 

 cult and unsettled in the range of geological inquiry. It is 

 indeed a very complex one, embracing several quite distinct 

 features. The enormous lateral compressions which have 

 everywhere crushed, folded, and contorted the stratified rocks, 

 culminating in vast uptilted and fractured mountain ranges, 

 may or may not have been instrumental in the elevation of 

 continents, and the depression of ocean-beds. The alternate 

 subsidence and emergence through miles of vertical oscillation 

 of continental areas — successively repeated (by the agency of 

 internal or external influences) — may or may not be correlated 

 with equivalent upheavals and submergence of the present 

 oceanic areas. And whether we infer with some geologists 

 that ocean and continent have more than once changed places, 

 or on the other hand conclude with Dana, and others, that the 

 skeletons of the existing continents were rudely blocked out 

 and the foundations of the great deep laid down in pre-archsean 

 times, we are on either supposition beset with grave and pecu- 

 liar alternative perplexities. The hypothesis of Joseph Le- 



*Read before the Philosophical Society of "Washington, May 23, 1885. 



Am. Joue. Scl— Third Series, Vol. XXX, No. 178.— Oct., 1885. 

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