1897- PLIOCENE FLINT-FLAKES IN BURMA. 237 



when found on the plateau, as near Minlintoung, they are strictly 

 confined to the outcrop of the ferruginous conglomerate. 



From the foregoing it will be clear why I did not mention the 

 second locality in my first paper, although personally fully convinced 

 that the flakes were derived from the conglomerate underneath, just 

 as much as the fossil bones. 



The view that an ancient settlement may have existed at this 

 spot can be discarded at once. Even if we admit that there was room 

 enough for it, what did the people live upon, and what is still more 

 important, where did they get their water from ? There is no spring 

 on the rocks for miles around ; in the ravines the water, when present 

 at all, is always undrinkable ; the water must therefore have been 

 carried from the river for several miles, and I greatly doubt whether 

 the ancient makers of the implements preferred to carry their drinking 

 water over several miles of rugged country, when they could have it 

 much more easily by settling on the river bank. 



The strata which are found around Yenangyoung are limited to 

 the Tertiary and Diluvial formation, the latter resting unconformably 

 on the tilted beds of the former. 



The Tertiary beds are represented by the younger Tertiary only, 

 the Nummulitic Formation being entirely absent, or at least not 

 coming to the surface. The oldest beds belong to the Miocene, but 

 although they have been proved by deep borings to be of considerable 

 thickness they crop out only over a small area. The beds belong in 

 small part to the Prome stage, and in larger part to the Yenangyoung 

 stage, terminating in the Batissa (Cyvena) bed, as explained in 

 vol. xxviii. of the Records of the Geological Survey of India (pp. 64, 

 et seq., 1895). 



Of the youngest Tertiary, the Pliocene or Irrawaddi Division, 

 not less than 4620 feet is exposed, although probably this does not 

 represent nearly the whole thickness. It consists of a series of soft 

 yellow sandstones, alternating with beds of clay, conglomerates, 

 and bands of very hard siliceous concretions of nodular shape. 

 Single beds do not continue for any distance ; they frequently die out, 

 and are at the same horizontal level replaced by others of a different 

 nature. Numerous instances will be found in my Memoir on the 

 Yenangyoung petroleum-field. It is therefore hopeless to attempt 

 any general sub-division from a lithological point of view, and any, 

 chiefly based on lithological differences, must be considered as 

 merely local. 



The conglomerates are frequently only pockets or patches within 

 the sandy beds, but sometimes they may be several miles in length, 

 and as they usually contain numerous remains of Vertebrata, they are 

 of the greatest importance for the study of the Irrawaddi division. 

 For this reason I devoted special attention to their examination 

 wherever I found such a bed, arid mostly my researches have been 

 rewarded, although the fossils seem to occur in rather an erratic 



