386 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1913. 



It is a fact well known to geologists that continents, and therefore 

 countries, have not always existed in their present state, but that they 

 have been built as a result of successive events and changes of condi- 

 tions. If we were to dig beneath the surface in any part of China, 

 we should find first one stratum and then another, and we should see 

 also that these strata have been bent, cracked, and otherwise disturbed. 

 Some of these structures are old and some young. It would be some- 

 what like excavating in an ancient city, where one house or temple 

 has been built upon the ruins of its predecessor, and each affords a 

 crude record of its time. The geologic structure of such a counti-y as 

 China has been determined largely by the rocks of which it consists, 

 partly by the climate to which it has been subject, but chiefly by the 



geologic events 

 which have oc- 

 curred during its 

 history. Of course 

 the beginnings of 

 that history are 

 unknown, just as 

 the human history 

 of China shades 

 into darkness 

 when we attempt 

 to trace it back 

 into the remote 

 ages. But the 

 present features of 

 the land are 

 chiefly due to the 

 later events in its 

 life, and these have been partly worked out by the geologists who 

 have explored its surface. 



We may take as a convenient starting point for our interpretation 

 a time far back in geologic chronology ,i when China was a land sur- 

 face which had been exposed to erosion so long that nearly all the 

 hills and mountains that may have existed there before had been worn 

 away, leaving a relatively flat plain, with groups of low hills here and 

 there. The rocks beneath this plain were of various kinds, most of 

 them highly folded. Eventually this surface was submerged beneath 

 a comparatively shallow inland sea ; and although the uneasy move- 

 ments of the earth's body caused the sea bottom to emerge occasion- 

 ally, it remained below the water nearly all through the geologic 

 periods Avhich constitute the Paleozoic era. By the end of that time 



Fig. 1.— Sketch Map of China. 

 Showing Its outlying dependencies and its relation to other countries. 



1 Just before the Cambrian period. 



