POST-TERTIARY. 113 



Upper cong-lomerates or clays about 2,500 feet,— making in all, roughly 

 speaking, 10,500 feet.* 



Post-tertiary and Recent. 



No. 15. — A still more recent set of pebble beds than those of the 



Siwaliks, capping the hills over the Kahan gorge 



near Rotas, has been referred to the post-tertiary 



group, or older alluvial, or high-level river shingle of Mr. Medlicott^s 



paper. t The same group was noticed long previously in the Salt Range 



(but included with the upper tertiary rocks) by Mr. Theobald. J 



I had noticed these beds in the Soan valley in the Potwar and 

 in other places. They contain frequently a large percentage of lime- 

 stone pebbles and sometimes are almost exclusively made up of either 

 these or of the same pebbles which occur in the uppermost Siwalik con- 

 glomerate. It has been said that the latter conglomerate wastes away 

 so as to furnish an enormous quantity of boulders covering the ground. 

 Where these lie thickly and are cut through by streams, the unconform- 

 able mass exposed, though perhaps but quite locally derived, has exactly 



* Mr, Medlicott has in his paper (Records, Geological Survey, Vol. IX, p. 49) indi- 

 cated much of the difficulty which prevented the full recognition of his groups in the 

 Northern Punjab until he was able to traveise the country reaching from the typical Sub- 

 Himalayan area to this district and identify them here himself. 



Although the general characters of the Upper Punjab Tertiaries agreed with the whole 

 Sub-Himalayan series, I was unable previously to fix the divisions with any certainty, because 

 1 could find neither the same stratigraphical breaks in the series, nor an exceptionally ossi- 

 ferous upper (or Siwalik) group. 



I had previously pointed out that the whole of the Potwar sandstones, &c., were more 

 or less ossiferous from the nummulitic (Sabathu) upwards, and Mr. Lydekker's reference 

 to fossils from some of the Mari beds near Kushialgar (Records, Vol. IX, p. 94) shows that 

 the occurrence of bones is not sufficient to fix the rocks as Siwalik ; the main characters 

 for the determination of the boundary between the Siwalik and the Nahan or Murree beds 

 in the field will therefore be position and lithological structure. 



f Records, Geological Survey, Vol. IX, p. 55. 



J Paper on the Salt Range, As= Soc. Beng,, p. 672. 



p ( 113 ) 



