CORALLIFEROUS SERIES OP SIXD. 



203 



area. But in the great central area of the Himalayas proper there 

 was no marine Miocene. >7o marine beds, the equivalents of the 

 Gaj series of Sincl and Burma, underlie the Sivalik deposits in the 

 Sub-Himalayas. 



There was open sea duriug the Xummulitic age where the great 

 semicircle of extra-peninsular mountains now exists ; and marine con- 

 ditions persisted on the west and east during the Miocene period ; 

 but a post-Xummulitic upheaval developed a land-surface and hill- 

 tracts from Kashmir to Assam. 



This upheaval commenced before, but culminated after, the close 

 of the Eocene age ; and a considerable thickness of purple sand- 

 stones, red clays, and grey and purple sandstones containing plants 

 accumulated in the swamps on the plains of that age, near the 

 mountains on the edge of the Xummulitic sea-floor. 



These plant-bearing strata and the underlying jSTummulite- 

 bearing strata have a minimum thickness of 2000 feet, and they 

 form the Sirmiir series of Indian geologists. 



This series underlies unconformably the vast freshwater sedi- 

 mentary formation comprising the ISahun and Sivalik strata, which 

 attain a thickness of about 15,000 feet, and, except where buried 

 beneath recent deposits in one locality, extend, with a varying 

 development, along the south of the great mountain mass, and are 

 found on one of the great tablelands to the north of the Central 

 Himalayan axis. The lower, or Xahun unfossiliferous, series con- 

 sists mainly of grey lignitiferous sandstones. On it the upper, or 

 fossiliferous Sivaliks, accumulated as sandstones and clays ; and on 

 the top of all are conglomerates. A great fauna is represented in 

 all parts of the Sivalik deposits above the Xahun beds. 



From the lie of these sedimentary strata, it may be very reason- 

 ably inferred that the ISTahun and Sivalik deposits are the equivalents 

 of the Lower and Upper Manchhars of Sind ; and the inference may 

 be extended to the Upper Tertiaries of Burma. There is an outlier 

 of this series and of its lower member in the Gulf of Cambay or 

 Perim Island. 



In attempting to establish exact parallelism between the Sindian 

 and the Hima]ayan deposits called Manchhar and Sivalik, it must 

 be noticed that the vertical development of the last-named rocks is 

 the greatest, and that whilst the lowest beds of the Sindian series are 

 fossiliferous, those of the Nahun beds of the Sivaliks are not*. On 

 the other hand, osseous remains are found throughout the Sivaliks 

 proper (above the IN'ahun beds), but not in the Upper Manchhars 

 in a recognizable form. 



The Manchhar and Sivalik series have been upheaved, uptilted, 

 and in the last instance greatly contorted. Both series were the 

 youngest implicated in the great orographical development; and 

 although they are on different lines of strike, they were affected 

 during the same geological period. 



The denudation of their exposed ed ges nas been great. Both are 



* Possibly the ossiferous deposit at Kushalghar, near Attock, is of ^uhun 

 age. See further on. 



