110 NOETLING : PETROLEUM IN BURMA. 



may observe at once a very curious feature. Very thick argillaceous 

 beds are found in all the wells which are situated inside the areas in- 

 dicated as depressions. This thick argillaceous bed was first 

 noticed in well No. n, extending from there towards No. 47 where 

 it is divided by a sandy layer. From No. 11 the argillaceous bed 

 passes between No's, 19 and 18 and to the north of No. 17. Its 

 horizontal extension must have been very limited in this region. 

 From north of No. 17 it must sweep around but outside Nos. 16 and 

 15, and it is seen again in the same thickness; its horizontal exten- 

 sion must be still more limited in this part. 



From there it passes outside No. 14, reaches up as far as No. 58, 

 although not in the same thickness as previously noticed, and must 

 pass west of No. 62, but east of No. 64, and passing No. 67 which is 

 probably close to its western limit. It appears in its former strength 

 again in No. 30, and reached up in the depression as far as No. 48. 



Slight traces are only noticed at No. 55, not at Nos, 32 and 35, 

 but in well No. 39 it again assumes the former thickness of over 200 

 feet divided only by a thin layer of sand. 



Its further extension cannot be accurately defined ; at No. 60 it 

 appears as a continuous layer of 260 feet in thickness, extends to the 

 south towards No. 63, where it reaches 295 feet in thickness, from 

 thence it sweeps round the southern end of the oil tract, being found 

 in No. V with 295 feet, in No. VI with 356 feet, and in No. VII with 

 290 feet ; near this point it is lost and it certainly does not appear on 

 the eastern side, but it unquestionably extends as far down as No. I 

 where it has been met with inconsiderable strength. 



This argillaceous bed is followed by a sandy stratum, which gener- 

 ally increases in thickness when the argillaceous bed decreases, and 

 vice versa. It deserves mention, that this second sand which begins 

 north of the oil tract, describes a similar series of folds to the 

 third sand, although it does not contain oil anywhere. 



Section X.— Before turning to the eastern side I wish to draw 

 attention to section X as this traverses the central ridge. This sec- 

 ( 156 ) 



