64 NOETLING: PETROLEUM IN BURMA. 



already been absorbed by the sandy layers before the latter was 

 hermetically sealed up and surrounded on all sides by a covering 

 layer of clay. 1 



This instance of petroleum occurring in sandy layers, surrounded 

 on all sides by clay, is repeated on a larger scale in the petroliferous 

 sands, although it is very difficult to prove, in this case, their entire 

 isolation and the absence of any communication with other beds. 

 The deep wells have, however, given in some instances such a 

 sequence of strata that it is impossible to interpret them in any 

 other way, but that a, comparatively speaking, thick bed of sandstone 

 is intercalated in and surrounded on all sides by argillaceous 

 beds. The presence of the petroliferous sand 2 (a) in Wells No. 6 

 [a), io, and 8, and its absence in all the surrounding wells, can 

 hardly be explained in any other way except that it forms a 

 lenticular arenaceous mass imbedded in clay. I may further add 

 that I actually observed a thick bed of sandstone dying out in an 

 argillaceous bed, — a subject which will be dealt with in a subsequent 

 chapter. 



To me it seems therefore beyond any doubt that the petroleum 

 stored in the petroliferous sands in the Yenangyoung oil field must be 

 indigenous, and that the assumption of an extraneous origin, and the 

 migration to its present receptacle, is incompatible with the observed 

 facts. 



Whether, however, the view of the indigenous origin of the Yenan- 

 gyoung oil field be accepted or not, the deep borings have proved that 

 it occurs within the area of the Yenangyoung oil field in at least six 

 different horizons. It may be almost considered as certain that the 

 above number does not represent the total of the petroliferous sands 



1 It may be advisable to point out that this conclusion is not so fully established as 

 Dr. Noetling's languages would suggest. The penetrating nature of mineral oil is well 

 known, and as Mr. H. B. Medlicott wrote in 18S6 (Rec. XIX, 191), "when we find geodes 

 filled with successive layers of minerals in the midst of compact basalt it is difficult to 

 place limits on the possibilities of permeation." Dr. Noetling's own observations on the 

 connection between geological structure and distribution of petroleum in the Yenang- 

 young oil field indicate that the present differs from the original distribution of the 

 oil ; this, however, is compatible with the original inclusion of it, or the materials from 

 which it was derived, in the beds in which it is now found — Ed. 



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