YENANGYOUNG. 



79 



joints. This is followed by about 6 to 8 feet of well stratified bluish 

 clay (2) which forms the surface, and is quite conformable to 

 the sandstone. The sandstone terminates suddenly, and is 

 replaced in the same level by bedded clay ; higher up the sandstone 

 continues some distance further, but it soon disappears entirely, and 

 near the left of the section nothing but a bed of well stratified clay 

 is seen. 



From these few instances it will be seen how utterly impossible 

 it is to identify correctly the different beds recorded in the deep 

 wells. 



This is, however, not the only difficulty which impedes a correct 

 interpretation of the boring registers. There are two more of no 

 small importance, viz., contemporaneous erosion and consequent local 

 unconformities within the series of the petroliferous beds. The best 

 instance of these two features is shown in a section in the Aungban- 

 yo just below the drilled well No. 38 which is reproduced on plate IX, 

 and the most interesting part of which has been constructed on the 

 base of very careful measurements in the following diagram. 





,-' .;_" 



— — _- _- \J_-— -r=z 



Fig. 4. Diagrammatic section showing double unconformity above the first oil sand 



in the Aungbanyo. 



The series begins with a fine, rather hard, sandstone of grey 

 colour slightly tinged reddish (1). The bedding of this sandstone is 

 to all appearances perfectly horizontal, a feature which is rendered 

 very conspicuous by thin partings of greenish clay. A bed (2), of 

 about 4 feet in thickness, rests unconformably on this sandstone, 



( 125 ) 



