16 



LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



At the mouth of the Nam-hsim the main river again turns to 



. . the south, and flows in a gradually deepening 

 Lower course of river. . ° * n 



channel to the southern border of the States, 



in about Lat. 22° 15', Long. 97° 15'. Here it receives a large 

 stream from the south-east, the Nam-hka, which drains the northern 

 and western flanks of the lofty isolated mass of Loi Pan, in the 

 sub-state of Mong Tung. It then again runs westwards to the lower 

 end of the Gokteik gorge, where it is joined by the Nam-panhse. 

 which, coming from the north-west, drains with its numerous small 

 tributaries the hilly country to the south of the Euby Mines 

 District. At this point the Nam-Tu again turns due south, for 

 about 24 miles, and then flows westwards, with a very irregular 

 course, issuing from the hills at Kyetnapa, about 14 miles south- 

 east of Mandalay. Below the mouth of the Gokteik gorge it 

 receives no tributaries of any importance, except the Hpawng-aw, 

 which drains the plain of Hsum-Hsai, and is joined, not far 

 above its confluence with the main river, by the Ke-laung, which 

 rises at Maymyo. 



It was mentioned above that, below the mouth of the Nam- 

 hsim, near Bawgyo, the valley of the Nam-Tu 



Gor' T c of the Myitn<*e. 



gradually becomes deeper. At Tong-ang ferry, 

 20 miles to the south, the river already runs between lofty cliffs 

 of limestone rising to between 200 and 300 feet above the water, 

 but below this the channel becomes a profound, narrow gorge, 

 with nearly, often quite perpendicular sides, through which the 

 water dashes in a succession of foaming rapids and long, deep, 

 gloomy pools, to which the light of the sun seldom penetrates, 

 except at mid-day. At the mouth of the Gokteik gorge the 

 channel has reached a depth of about 2,000 feet, but from here 

 the fall does not increase so rapidly, though the river is nowhere 

 navigable except for short distances by dug-out canoes or bamboo 

 rafts. 



One or two points of special interest regarding the development 

 of this river may be noted. In the first 

 Recent development of place its course is almost entirely confined to 

 the formation known as the Plateau limestone. 

 In only one portion of its course, in the long meridional traverse 

 to the north of Hsipaw, does it run for any considerable distance 

 through the older Palaeozoic rocks underlying this limestone, though 

 iu the deep gorge below Tong-ang it cuts transversely through them 



