HISTORICAL SUMMARY. 



355 



along the edge of the hollow, and in the latter case in the folding 

 of strata of similar age along its centre ; but I will return to the 

 consideration of this matter later on (p. 357). 



If the formation of these depressions was in progress during the 

 Carboniferous period, they would account fo 



Possible se3i connec- 



tion with Salt Range the replacement of the purely European 

 in Permo -Carboniferous f aU n a of Padaukpin, and of the stages which 



preceded it, by the Middle Productus fauna of 

 the Salt Range and Himalaya that we find in the Shan States at 

 the close of that period. But, as soon as these limestones had 

 been deposited, there was either a pause in the submergence or, 

 more probably, the eastern or Burmese thrust predominated for a 



time over that from the north, and an eleva- 



Tnassic unconformity. . „ . . , . . . . 



tion oi the Shan area above the level ot the 

 sea took place. This wa& perhaps merely sufficient to allow the 

 surface of the limestone to hi worn into hills and hollows, 

 but it kept the surface above water for a considerable period, 

 through Permian and Triassic times. 



At the end of this period of emergence the surface of the 

 Rh tic submergence limestone was again covered by the waters 



of the sea, and the Rheetic shales and lime- 

 stones were accumulated on the uneven floor into which it had been 

 worn. This submergence seems to have been quite local, and at 

 the same time the old land surface to the north-east may have 

 been gradually rising, with a consequent advance southwards of 

 the coast line, until the sandy sediment derived from it was 

 swept down and formed the red beds of the Nsimyau series. 



Advanc- f Continental conditions had prevailed through- 



nental conditions. out Central China and Yunnan during Permian 



and Triassic times, resulting in the accumula- 

 tion of the red coal-bearing system of Sze-chuan ; l and these 

 conditions now invaded our area, so that before the close of the 

 Jurassic period, we find a great series of red sandstones and shales, 

 with carbonaceous layers and plant beds, spread over the whole 

 of the eastern border of Condwana land, from North-eastern China' 

 to the Southern Shan States. The connection that I have supposed 

 to exist with the southern ' Tethys ' must have been of very short 

 duration, for none of the Jurassic ammonites of the Himalaya has 



l Bailey Willis, Research in China, Vol, II, Chap. VI. 



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