332 LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES 



From Tonbo to Sedaw the line rises very gradually over a low 

 _ , A , _ , fan, formed of gravel and boulders washed 



Ion be to Sedaw. , ~ mi 1 



out trom the feedaw gorge. Lo the south the 

 lofty mountain known as the Myaleit-daung, on the opposite bank 

 of the Myitnge (Nam-Tu), attracts the eye by reason of its bold 

 craggy pinnacles. This hill also is composed of the Plateau Lime- 

 stone, clipping steeply towards the plains. 



At Sedaw we begin the ascent to the plateau by a series of 

 „ , zig-zags terraced out of the hill side, which is 



Ascent from Sedaw. . , , . 



a dip-slope 01 almost bare limestone steeply 

 inclined to the west. Sections of gastropods and bivalves may be 

 seen here and there on the weathered surface of the rock, but are 

 all converted into calcite and useless to the collector. On turning 

 bhe shoulder of the hill and passing through a very short tunnel 

 the beds bend over and dip towards the north-east, continuing so 

 for a few hundred yards to a narrow saddle, immediately below 

 the third Reversing station, at the head ot a deep ravine running 

 down to the Sedaw river. Here a sudden change takes place 

 lt in the character of the rocks. The saddle 



and the ridge beyond is composed of red 

 shaly limestones, which by their intensely crushed appearance and 

 slickensided surfaces suggest the proximity of a fault. They belong 

 in fact, to the Naungkangyi series, probably to the upper part of it 

 or Nyaungbaw stage, and are brought against the grey limestones 

 by a great fault, which can be traced for many miles to the north 

 and south. Here they contain no fossils, except a very occasional 



fragment of a crinoid stem or Orthoceras, 



Fossils. . . . . 



converted into calcite ; but the rich collection 



of cystidean remains described by Dr. Bather in Mr. Cowper Reed's 



Memoir was made in the ravine mentioned above. This locality 



(Loc. 88, B 5), however, is almost inaccessible from this point, 



but it may be reached conveniently by a path leading from Sedaw 



station along the bank of the river and passing round the northern 



end of the hill of the zig-zags. 



Leaving the fourth and uppermost Reversing station, the line 



passes through a deep cutting and two ' cut 

 Line below Zebingyi. , , . 7 i ■ 



and cover tunnels, excavated in greatly 



crushed shaly limestones with a high easterly dip, probably belong- 

 ing to the Nyaungbaw stage, but without recognisable fossils. 

 Neither the lower brachiopod-bearing Naungkangyi beds nor 

 upper variegated shales with trilobites, etc., are seen here, being 



