VOLUME XXXI NUMBER 1 



THE 



JOURNAL OF GEOLOGY 



y anuary -February 102 J 



THE CYCLE OF EROSION AND THE SUMMIT 

 LEVEL OF THE ALPS 



W. M. DAVIS 



CONTENTS 



Part I. Penck's Essay on the Summit Level of the Alps 



A leading feature of the Alps 



The preglacial form of the Alps 



First ideal cycle: Erosion during prolonged upheaval 



Balance of upheaval and erosion 



Second and third ideal cycles 



Uncertain application of the first ideal cycle to the Alps 

 Part II. The Scheme of the Erosion Cycle 



Physiographic principles of the erosion cycle 



The terminology of the erosion cycle 



Gradual development of the cycle scheme 



Reception of the scheme of the erosion cycle 



Objections to the scheme of the cycle 

 Part III. Penck's Criticisms of Earlier Studies 



Progress in Alpine physiography 



Extensions and corrections of the erosion cycle 



Independence of upheaval and erosion 



Interaction of upheaval and erosion 



Complications of the erosion cycle 



Definition of the initial surfci,ce 



Practical exercises on plateaus and mountains 



The explanatory description of land forms 



Closing remarks 



