CHAPTEK XV. 



MANDALAY-LASHIO RAILWAY TRAVERSE. 



In order to present a concise review of the stratigraphical 

 features of the Shan plateau described at length in the foregoing 

 pages, it may be interesting and useful to give here an account 

 of the geology that may be observed along the line of railway 

 connecting Mandalay with Lashio ; for, with a few exceptions, all 

 the formations mentioned are to be met with on the line itself ; 

 wbile those that are not actually seen in the cuttings may be 

 visited conveniently from one or other of the numerous railway sta- 

 tions. Many years will probably elapse before communications are 

 so improved that visitors will be able to travel to localities far 

 removed from the railway without having to make arrangements 

 for a regular camping outfit. 



On leaving Myohaung, the junction with the main line near 

 Mandalay, the railway traverses the alluvium 

 Irrawaddy plain. ^ ^ e Irrawaddy valley in a south-easterly 

 direction for about 12 miles. To the north Mandalay Hill is 

 seen rising above the city, composed, as well as other isolated hills 

 surrounded by the level alluvium, of crystalline limestone and 

 gneiss traversed by granite veins, belonging to the gneissic series of 

 Mogok. These rocks also form the long range of hills closing the view 

 to the west, on the opposite bank of the Irrawaddy, and along their 

 base may be seen deeply indented terraces of yellow sand-rock, which 

 have yielded a rich harvest of late Tertiary mammalian remains. 

 The level ground continues to the first station, Tonbo, imme- 

 diately to the north of which the limestone 

 rocks of the Shan plateau emerge from beneath 

 the alluvium, forming a series of ridges gradually increasing in 

 height until the main ascent is reached at Sedaw. The beds at 

 Tonbo, which are quarried for lime-burning and road-metal, dip steeply 

 towards the plain, and the same dip, more or less accentuated, 

 is seen in all the ridges. At the point of the ridge nearest to the 

 station (Loc. 27, B 5) the rock contains a fair number of fossils 

 (of which Fusulina elongata Shum. is the only species determined), 

 most of them corals converted into white calcite, and easily dis- 

 tinguishable on the surface of the dark-blue limestone in which they 

 are imbedded. A band of shelly limestone, filled with fragments of 

 brachiopod shells, occurs at the southern end of the second ridge 

 near Kyuwun, but no fossils worth collecting were obtained here. 



