PHYSICAL GEOLOGY. 



19 



were an important river, considerable changes would be introduced 

 into the river system of the country. 



The Salween, forming the eastern boundary of the settled portion 

 of the Northern Shan States, 1 does not, n spite 



The Salween. . . .. . , ' r . 



of its size and importance, play much part in 

 the river system of the plateau. It has already been remarked that 

 the Nam-Tu and its eastern tributaries, the Nam-yau, the Nam-ma, 

 and the Nam-hka, all rise within a short distance of the Salween, 

 which receives no affluents of much importance in its course 

 through these States. The Nam-pang, the head- waters of which 

 drain the eastern and southern slopes of Loi Ling in South 

 Hsenwi, properly belongs to the Southern Shan States, and enters 

 the Salween a long way to the south, in the State of Keng Hkam. 



For a very long distance above the point where the Salween 

 enters the Shan States, indeed as far north as we possess any de- 

 finite information about the river, it presents the same characters 

 as in British territory. It occupies in Yunnan, where it is known 

 as the Lu Kiang, a long, deep, trough-like valley, closely com- 

 pressed between the 'Nmai kha, or eastern branch of the Irrawaddy, 

 the Shweli further south, and the Mekhong, and receives no tribu- 

 taries except mere mountain torrents. Its main catchment area lies 

 well to the north of the sources of the Irrawaddy, indeed it is 

 spoken of as a ' great river ' by the French missionaries who were 

 for some years stationed near it about Lat. 28° 20', or roughly 

 on the parallel of the sources of the Irrawaddy. Prince Henri 

 d' Orleans mentions that, where he crossed the Lu kiang, in about 

 Lat. 26°, the waters of this river are easily distinguished from those 

 of the Lan-tsang kiang, or Mekhong, by reason of the dirty grey 

 colour of the former. This seems to indicate that the Salween 

 rises in a land of glaciers, perhaps somewhere near the Kuen Lun 

 mountains. 



It may be remarked that the Salween, throughout its whole 



course, flows through palaeozoic or Archaean 



Ancient origin of the roc ks, and, unlike the Irrawaddy or the Hima- 

 Salween. , . rf . 



layan rivers, it does not issue into a broad 

 plain composed of Tertiary or Kecent deposits, but maintains the 

 deep, rocky, trough-like character of its valley to within a few 

 miles of the sea coast at Moulmein. It is much more effective, 



1 The country east of the Salween in this latitude is occupied by wild hill tribe 

 known as the Wa (or Lawa), and has not yet been brought under control. 



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