VENANGYAT. 1 27 



Subdivision. — Although in the absence of any well defined 

 palaeontological features a subdivision based on this evidence is 

 impossible for the present, a certain sequence of strata has been 

 noticed, which seems to continue for a considerable distance in a 

 horizontal direction. In descending over the beds distinguished are — 



a. Blue clay, a very conspicuous bed particularly marked by the 

 contrast which its bluish colour forms to the overlying whitish yellow 

 of the Irawadi series. In thickness it is between 40 and 50 feet, 

 and as far as observed it seems to form a very constant horizon 

 within the tract of the Tangyi range. 



b. Yellow sandstone ; below the above mentioned clay follows a 

 dark yellowish, rather soft sandstone of about 20 to 25 feet in 

 thickness. 



c. Olive coloured clay bed of soft, thickly bedded clay of olive 

 colour, containing large quantities of gypsum of about 60 feet 

 thickness. The hard argillaceous concretions of this bed contain 

 occasionally fragments of fossils. 



d. Signal hill sandstone ; a bed of sandstone of the same charac- 

 ter as No. 2, so called because it forms the top of a hill where there 

 is one of the main signals of the Yenangyat oil field survey, 

 thickness about 20 to 25 feet. 



e. Olive coloured clay ; full of gypsum, the same as No. 3. Thick- 

 ness about 60 feet. 



f. Pagoda sandstone ; the same as Nos. 2 and 4 ; forms the sur- 

 face of the hill on which the Sehwemyindin Pagoda has been built. 

 It is apparently a little harder than the other beds ; its thickness bein°- 

 about 20 to 25 feet. 



g. Olive coloured clay, as before ; thickness about 40 to 50 feet. 

 k. Sandstone, as before; thickness about 15 feet. 



i. Olive coloured, somewhat more bluish clay, forming a bed of 

 approximately 190 feet in thickness. Strings of hard concretions 

 are very common, covering the slopes in large heaps where the bed 

 crops out. 



Forming an opinion from the above section, the total thickness of 



( 173 ) 



