54 NOETLING: PETROLEUM IN BURMA 



bottom or at the top of the series. Even now the subdivisions 

 of the Yenangyoung tertiaries, as described in the following pages, 

 must only be considered as a first attempt ; it remains to be seen how 

 far it will hold good for the larger part of the Burman tertiaries. 



2. — Geological Features. 

 The strata developed in the neighbourhood of Yenangyoung may 

 be divided as follows : — 



A. Diluvium. 



B. The tertiary system. 



A, — Diluvium. 



It might perhaps be questioned whether this term ought to be 

 applied to the beds which I am here briefly describing; it is not im- 

 possible that perhaps the term older alluvium would be better, as we 

 do not possess absolute evidence by which the diluvial formations in 

 Burma can be correlated to the same formations in Europe. 



I consider as diluvial all those strata which rest unconformably 

 on the tilted beds of the pliocene in such a manner that they can be 

 clearly recognized as having been formed before the present system 

 of drainage was established. 



Within the limits of the above definition the diluvial strata can 

 be easily recognized everywhere in Burma, as they are generally 

 found high above the level of the present rivers, and are always cut 

 into by the present drainage. Near Yenangyoung two facies of such 

 beds may be observed, namely : — 



(i) Lower silt. 

 (2) Plateau gravel. 



(1) The lower silt. — The lower silt may be noticed just south of 

 the Pin-choung, but becomes more conspicuous near Kyaukse, where it 

 is a fine silt, horizontally bedded, and apparently deposited in the syn- 

 clinals and hollows of the pliocene beds, which it most closely 

 resembles lithologically, and for which it might easily be taken, 

 if the bedding is not clearly seen. At Kyaukse, I observed on the 

 river bank, that typical pliocene beds, dipping towards west, were 

 unconformably overlaid by a series of horizontal beds of fine silt ; 

 (100 ) 



