INTRODUCTION. 



The expedition to China carried out in 1903-04 under the auspices 

 of the Carnegie Institution of Washington gathered certain observations 

 relating to the geology of that country, which are stated in detail under 

 the general subject of descriptive geology, in volume I, part I, of these 

 contributions. The same material is treated in this volume, but from the 

 standpoint of systematic continental history. Repetition has been avoided, 

 so far as is consistent with the presentation of the general subject. Other 

 sources of published information have been freely consulted and are referred 

 to in connection with the discussions. 



The subject-matter of this volume is classified primarily according to 

 geologic eras or periods, and secondarily by broad areas of which China 

 proper is the central region. Thus the reader will find that each chapter 

 treats of the geographic condition of southeastern Asia during a particular 

 age, and that successive chapters trace the sequence of changes from age to 

 age. Only the great events of continental history are distinguishable on 

 the basis of existing knowledge, but they suffice to show that the present 

 continent is an aggregation of land masses which, from time to time, have 

 been forced into union with one another. This generalization has already 

 been stated by [Suess, who, in cooperation with Neumayer, developed the 

 recognition of the great mediterraneans which formerly divided Eurasia. 



This study of Asia has been carried on with comparative studies of 

 North America and Europe, and has led to theoretical views regarding 

 continental structure and development which have a broad application. 

 They are briefly stated in a closing chapter. 



Many associates have helped me toward an understanding of the prob- 

 lems involved, and I desire to express my appreciation of aid received from 

 geologists and physicists alike. An especial debt is due the two great 

 leaders in the modern advance of geological philosophy, Chamberlin and 

 Suess, from whose works and personal suggestion I have derived the 

 highest inspiration. Their assistance is none the less earnestly appreciated 

 because I have been compelled to a somewhat divergent view in theoretical 

 questions of continental development. 



BAILEY WILLIS. 

 WASHINGTON, D. C, February 25, 1907. 



v 



