338 L 



A TOUCHE: GEOLOGY OF NORTHERN SHAN STATES 



Fig. 11. Branches of the Hpawng-aw R. on the Plateau of Hsum Hsai. 

 Scale 1" = 4 miles. 



^ it there is a distinct fault along the crest, with 



a down throw to the west. Further to the 

 south, however, the throw increases until the relative difference in 

 level becomes about 3.000 feet, and the rocks underlying the lime- 

 stone, the Namhsim and Naungkangyi beds, are brought up to 

 the surface. At the pass the fault has preserved a patch of the 

 Napeng shales, and of the hard blue limestones beneath them, the 

 latter being exposed in the 'borrow pits' on the ascent and the 

 shales near the crest, just before the line enters a deep cutting 

 through the limestone (Loc. 11, D 3). The shales dip towards 

 the fault and are full of fossils, which may be collected either at 

 the side of the line or on the cart-road above. The limestone in 

 the cutting is intensely crushed, and traversed by beautifully 

 polished ' slickenside ' planes, evidently due to the proximity of the 

 fault. 



