MANDALAY-LASHIO RAILWAY TRAVERSE. 



343 



by the Namhsim sandstone. A little further on, near Namsio, 

 . we come upon the southern end of the great 



Lilu overthrust, which appears to be cut off 

 by a cross fault running along the valley we have been ascending, 

 and this brings up the Naungkangyi beds, which fill the whole of 

 the valley below Pangksa-pye. The road follows the upper margin 

 of these beds, and the purple band at the top, crowded with cri 

 noid stems and containing an occasional trilobite, is seen at inter- 

 vals. Fragments of the white graptolite shales may also be picked 

 up, but their outcrop is above the path, and concealed by rain- 

 wash and jungle. They are in situ on the saddle on which Pang- 

 hsa-pye is built, at the foot of a sandstone scarp, a quarter of a 

 mile to the south-east of the village (Loc. 65, F 2). The outcrop 

 is apt to be concealed, but may easily be found by working 

 upwards from that of the purple band, which is well 

 exposed on the narrowest part of the saddle. Fossils are also 

 to be found in the Namhsim sandstones forming the scarp 

 above, and in the lanes of the village itself good collections mav 

 be made from lower members of the Naungkangyi group. The 

 plane of the overthrust may be reached by following the path 

 leading westwards along the crest of a narrow ridge for about 

 half a mile, and is recognisable by a sudden change in the char- 

 acter of the rocks, the shales giving place to sandstones, though 

 the dip preserves the same direction, to the south-east. Poorly 

 preserved specimens of Ckthonota and Pycnom/phalus (?) may be 

 found in these sandstones, showing that they are of Silurian age, 

 though they dip below the Ordovician shales. 



Continuing the railway journey from Hsipaw eastwards, about 

 _ . four miles above the town the vallev of the 



Hsipaw to Se-in. , T , _ . , . i 



Mam- lu closes in, becoming narrow and V- 

 shaped, and from this point onwards the line is carried along the 

 banks of this river or its tributaries, the Namma and the Namyau, 

 to within a few miles of Lashio. The red sandstones and stales of 

 the Namyau series are well exposed in a series of deep cuttings 

 along the whole of this part of the line, generally showing very 

 high dips, as the railway cuts diagonally across the compressed 

 north east — south-west folds into which the rocks are thrown. Fine 

 examples of ripple marking may be seen on the surface of the 

 layers of sandstone in the deep cuttings near Hsunlong (F 2), but 

 as a rule these beds are not interesting. About 12 miles from 

 Hsipaw the Narn-Tu issues from a narrow gorge in these rocks and 



