336 LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



an iron mine, from which the place, Thondaung, takes its name. 

 The mine, which does not seem to have been much more than 

 a prospecting adit, is now rilled in, but the ore may have 

 occurred as the infilling of fissures in the limestone. 



The lowest beds of the Plateau Limestone are well exposed in 

 the cuttings further on, and are more flaggy 



Main plateau. , . ft . , ' , 



and sandy than usual, but they soon give 

 place to tho crystalline dolomite, which continues the whole way to 

 Maymyo, with the exception of a small cutting passed through a 

 little to the west of Letkaung, at the foot of the final ascent (Loc. 

 26, B 4j. Here there occurs one of the few bands of shale that 

 are in terstra titled with the limestone, but the only fossil found in 

 it is a small Lingula. The Zebingyi beds are not seen again on the 

 railway, but they run parallel to it on the north, along the Test 

 of the precipices that flank the Sedaw gorge, and approach the 

 line closely at Myenigon (Loc. 40, B 5), near Ani-sakan station. 

 At Letkaung, mentioned above, the Xaungkangyi variegated 

 • b d shales approach to within a short distance of 

 the line, but are not cut through by it. In 

 fact, from Thondaung to Hsipaw, a distance of 104 miles, measured 

 along the railway, it passes almost without exception over the 

 Plateau Limestone. The Naungkangyi beds may, however, be conven- 

 iently visited from Maymyo, as they form the whole of the hills 

 lying within two miles to the north of the town. The fossil local- 

 ities of Palin, Ledet, Lebyaungbyan, and Makyinu (Locs. 81-84, B 4), 

 are all within a day's ride, and along every path, wherever the 

 rock is exposed, the remains of Cystideans and other fossils may be 

 collected. 



Beyond Maymyo the line runs across the limestone plateau to 

 t . Wetwin, where it descends a precipitous scarp 



facing the valley of the Ke-laung stream, 

 from the crest of which a fine view of the plateau may be obtained 

 closed on the east by an even-topped scarp following the line of 

 the great Kyaukkyan fault. At our feet the village of Wetwin 

 is seen, nestling in a shady grove of jack-fruit trees (Artocarpus 

 integri folia), and built upon the only exposure known of the 

 Wetwin shales (Loc. 29, C 4). Outcrops of these beds 

 may be found in the watercourses and in the banks of the lanes 

 surrounding the village, but are apt to be much concealed by 

 vegetation. The middle Devonian locality of Padaukpin may also 



