CONTENTS 



Page 

 Introductory Sketch 7 



More than One Cycle of Erosion ------ 9 



Theoretic Considerations --------- 9 



Evidences of More than One Cycle ------ 12 



Interrupted Profile ----- 12 



Stream Terraces ------13 



Intrenched Meanders ----------15 



Associated Sets of Straight and Crooked Streams 19 



Antecedent Streams ---21 



Windgaps -------------24 



Even-crested Summit Areas ------- 26 



In Regions of Folded Strata ------ 27 



In Regions of Horizontal or Nearly Horizontal 



Strata - ---.__- 28 



In Regions of Igneous Rocks ------ 30 



Intermediate Plains ----------31 



Fluvial Deposits on Uplands -------33 



Combinations ------------34 



:More than T\vo Cycles ---------- 37 



The Determination of Diastrophic Events - - - 39 

 The Number of Movements --------39 



The Nature of Movements ---------40 



Uniform Uplift ------ 40 



Uplift with Tilting ---------- 40 



Uplift with Warping ----------41 



Uplift with Faulting ---------- 43 



Subsidence -------------44 



The Amount of Movement ---------44 



The Determination of Dates -------- 45 



The Ages of Old Erosion Surfaces ------ 45 



The Dates of Movement ---------47 



The Duration of Geologic Time ------- 48 



Conclusion of Part I-----------49 



