66 NOETLING: PETROLEUM IN BURMA. 



of petroleum was found in a bed which may be correlated with the 

 second oil sand. On the other hand it must have contained consider- 

 able quantities of petroleum to the north and south of Kodoung as 

 there are still a good many of the pit wells which draw their oil 

 from the second oil sand. As regards the chemical quality of the oil 

 of this horizon, it is almost certain that it is on the average of lighter 

 specific gravity than the oil from the first sand, although a little 

 heavier than that of the fourth sand. 



3. The third oil sand.— The independence of this layer seems 

 questionable ; so far it has only been observed in few wells to the 

 north of the Kodoung, such as No. A, No. 6, No. 8, in all of which 

 cases it is separated from the next following fourth sand by a com- 

 paratively thin bed of clay, which renders it very probable that this 

 layer only forms the top of the fourth oil sand, locally separated by 

 an intervening bed of clay. In all cases it contained a considerable 

 quantity of petroleum. 



4. The fourth oil sand.— This is the bed which supplies the greater 

 quantity of oil found at the Yenangyoung oil field. It has been gene- 

 rally found at depth ranging from 220 to 250 feet from the surface, 

 but of course the depth must vary for different reasons ; and as regards 

 thickness it varies so much that there are hardly two wells where it 

 exhibits the same thickness ; it may not be more than 20 or 25 feet 

 in one welL, while it exhibits a thickness of nearly 300 feet in another. 

 The reasons of this variation will be dealt with in another section. 

 The fourth oil sand contains petroleum throughout the Yenangyoung 

 oil field ; it seems that the oil from this sand is lighter in specific 

 gravity than that of any of the upper sands, inasmuch as its average 

 specific gravity is 0*8766 or 0*8921 at 6o° F. 



With regard to the deeper oil sands, it must be said at once that 

 only the merest indications can be given, because only a few wells 

 have reached a greater depth, and these wells are so far distant 

 from each other that a correlation of the various strata observed 

 seems almost impossible. The difficulty is particularly increased* 

 because it seems that the various sands noticed in the different 

 ( 112 ) 



