MANDALAY-LASHIO EAILWAY TRAVERSE. 339 



From this point the line runs to Nawnghkio, where the descent 



to the Gokteik gorge begins, over an al- 

 Gokteik gorge. . 6 & ., 6 



most level plateau, with a fine view, across 



the valley to the north, of the rugged hilly country beyond the 

 Nam-panhse, composed of the Chaung-Magyi slates and quartzites. 

 The richly fossiliferous locality of Chaungzon (Loc. 96, D 3), where 

 the brachiopod-bearing lower Naungkangyi beds are exposed, may 

 be visited from here. It lies on the cart-road, which descends the 

 scarp to the north of the village by a series of zig-zags, at the 

 point where the river at the bottom of the gorge first comes into 

 view. The variegated upper Naungkangyi shales are also exposed 

 between this point and the Chaungzon bridge, but not very clearly. 

 The railway descends the scarp further to the south-east, to the 

 ' Natural Bridge ' and viaduct, where the officials have provided 

 a comfortable bungalow for the convenience of tourists, many of 

 whom visit the place during the cold weather to view the wonders 

 of the gorge. On the descent numerous cuttings are passed through, 

 for a considerable distance in Plateau Limestone dipping towards 

 the gorge, and near the viaduct in travertine deposits which thickly 

 clothe the slopes above the deep cleft through which the river 

 flows. The opposite side of the gorge is a vertical wall of massive 

 limestone, thickly festooned with travertine, which the railway climbs 

 diagonally through a series of tunnels and loops to a plateau on 

 the same level as Nawnghkio. 



Beyond this nothing of interest is seen until Nawngping is reach- 

 ed. Two miles to the north of this station 



^Sink-hole at Nawng- jg the cur i 0U s ' p j pe ' mentioned on page 287, 

 filled with shaly clays containing crustacean 

 remains, probably of Napeng or Rhsetic age, and encrusted with 



an ancient travertine deposit (Loc. 12, D 3). From this point 



to Pyaunggaung the line runs entirely through the Plateau 



Limestone. 



From Pyaunggaung a visit may be made to Namsaw, or as 

 the Shans call it, Mong-tim, a village lying 



Sections at Nam saw. . , _ ., . , , , 



about 0 miles to the north-west, where, within 

 a space of less than two miles square, all the Palaeozoic formations 

 mentioned in these pages, with the exception of the lower 

 Naungkangyis, may be seen ; but- the structure of the ground 

 is so complicated that it is difii'uilt to make out the relations 

 of the formations to each other. Looking westwards, the lofty 

 hills across the Nam-Tiing, on the banks of which the village is 



z 2 



