63 GRIMES : MVINGYAN, MAGWE AND PAKOKKU DISTRICTS, 



III. The Gwegyo anticline.— In a south-westerly direction from 



The Gwegyo range of the end of the Pa g an Mis we see the northern 



h,lls * end of another range of hills formed by beds 



_, . L . , ,. .. bent into an anticlinal fold whose axis has a 



Position and direction. 



similar direction to the axis of Pagan anticline, 



but is not in the same line with it. Like the Pagan hills, the 



Gwegyo hills are composed of upper miocene 



compose thfhiifr bedS Yenangyaung beds, but here the pliocene beds 



are exposed in the surrounding country to the 



northern part of the hills; around the southern part of the range* 



however, the country is entirely covered by recent deposits. This 



anticlinal arch is also faulted close to its crest, 



not by a single fault but by a series of faults 



in different directions, consisting of one main fault in a direction 



varying from 5 E. of N., W. of S., to 5 VV. of E., N. of S. and 



of several smaller cross. faults ; in the hills close by Nyaunigyin the 



shifting caused by one of these faults may be distinctly seen and 



different beds are exposed in the cliff on the two sides of the 



fault. Owing to this faulting along the eastern side of the hills the 



beds on the east side of the anticlinal arch are only exposed in a 



few places, and then it may be seen that the anticline is somewhat 



unsymmetrical, but not so much so as that in the Pagan hills ; on the 



east side I have measured dips of 62 to the east, whilst the general 



westerly dip is about 40 . Along the greater part of the hills the 



eastern face is a scarp of the westerly dipping beds. 



The upper miocene beds in these hills are similar to those else- 

 where, greyish and brownish sandstones with 

 interstratified beds of greenish or greyish 

 shale. Unlike the rocks in the Pagan hills the shales are here 

 predominant and the beds much more like those at Singu, but 

 the uppermost bed of white sandstone is here wanting. I did not 

 find any Prome beds exposed or any traces of oil, but amongst the 

 basal upper miocene beds, which are exposed, there are some 

 shales which are very like those in the Lower 

 Petroleum: none seen. Miocene at Yenangyaung. The villagers too 

 ( 68 ) 



