3(50 LA TOUCHE: GEOLOGX OF NORTHERN SHAN STATUS. 



To the east of the Nam-Tu we have abundant evidence of the 

 effects of this form of dislocation. The red 

 c^! dinS ° f Nam J au beds of the Jurassic Nanrvan series are thrown 

 into regular folds striking from N.N.E. to 

 S.S.W.. and the Plateau Limestone is also affected in the same way, 

 so that we have a more or less regular series of parallel bands of 

 the two formations, somewhat modified by subsequent faulting, and 

 partly removed by denudation, extending along the valley of the 

 Namyau beyond Lashio. 



In the Eastern Ranges the dislocations take the form of more 

 or less elongated domes, usually with a core 

 Ran™ 1 ™* ° f Eastern of the more ancient rocks that constituted the 

 floor of the Palaeozoic sea. There is a con- 

 siderable diversity in the direction of their longer axes, and in 

 their shape and size, evidently due to the presence of these old 

 rocks. Thus the Loi-len range, and those to the north of it, 

 beyond the limits of the map, trend east and west, but with a 

 tendency at their western ends to swing round to a south-west 

 direction. The longer axis of the dome-shaped mass of Hwe Mawng 

 and Silurian strata to the east of Loi Ling, on the contrary, runs 

 north and south ; and this is also the direction of the ranges 

 east of Mong-Yai, much modified by faulting, and of the folds 

 along the eastern flanks of the Loi Pan — Loi Twang range. The 

 Loi-len range is the only instance in which the Plateau Limestone 

 is now found actually arching over the crown of the dome. In 

 the other cases it has been entirely denuded away, if it ever 

 existed as a continuous sheet, and now occupies only the low 

 ground separating one range from another. 



The outcrop of the formations concerned thus forms a series of 

 j_ j oval bands in plan, broadest in the centre 



where the maximum elevation has taken place 

 and the old sea floor is brought to the surface, and dying away at 

 either end. In some cases the single intense fold at the centre breaks 

 up into minor undulations towards the ends of the dome. An instance 

 of tin's structure is exhibited by the eastern end of the Loi-len range. 

 At the western end of tliis range, below the limestone scarp south 

 of Tileng, the Silurian marls, purple shales, and Naungkangvi beds 

 appear together, forming a compressed band only a few hundred 

 yards in width. Following these eastwards, the Chaung Magyi rocks 

 appear beneath the Naungkangyis, and quickly widen out, forming 



