Oct. 19, 1883.] 



♦ KNOWLEDGE ♦ 



241 



their greatest width and elevation l)etween the Chenab and 

 the Indus, cover an area of 1.3,000 square miles. The 

 whole of this material has been derived from the adjacent 

 Himalayas, representing many feet of the older and higher 

 mountain ranges, and has travelled down valleys that had 

 been excavated in pre-tertiary times. 



This points to a slow subsidence of the whole southern 

 side of the mountain mass, deposition generally keeping 

 pace with it, broken off by recurring long intervals of re- 

 elevation. Many long and instructive pages of its history 

 are written on these rocks. These sub-Himalayan forma- 

 tions arc fresh-water or torrential, showing that since 

 nummulitic or eocene times the sea has never washed the 

 base of the Himalayas. In fact, there is no evidence of 

 this from the gorge where the Ganges leaves the mountains 

 up to the base of the Garo Hills ; pointing to an extension 

 northward at that early age of the Arabian Sea, separated 

 from the Bay of Bengal by peninsular India. From 

 Assam to Scinde there probably once existed one con- 

 tinuous drainage line, a great river receiving its tributaries 

 from the Himalayas, partly a land of lakes and marshes, 

 the home of that wonderful mammalian and reptilian 

 fauna which Cautley and Falconer were the first to bring 

 to light. The Kashmir basin drained at the north-west 

 end into the Kasliingunga Valley to Mozutferabad, and 

 that of Hundes and Ladak trended towards the same 

 direction vid Dras. 



The southern boundary of this long alluvial plain was 

 formed by the present peninsula of India, and probably of 

 the extension of the Garo and Kliasi Hills westward to 

 the Rajmahal Hills. Depression has been considerable in 

 the neighbourhood of Calcutta, nearly 500 ft. We know, 

 probably, only a portion of the alluvial deposits. At 3S0 ft. 

 beds of peat were passed through in boring, and the lowest 

 beds contained fresh-water shells ; the beds also were of 

 such a gravelly nature as to indicate the neighbourhood of 

 hills, now buried beneath the Ganges alluvium. This is 

 precisely the appearance of the country above Calcutta on 

 approaching the present valley of the Brahmaputra. The 

 western termination of the Garo Hills sinks into these 

 later alluvial deposits, and along the southern face of the 

 range up to Sylhet, the waters of the marshes, during the 

 rainy season, wash the nummulitic rocks like an inland sea, 

 and point to the very recent depression of all this area. 

 The isolated granite hill- tops jutting up out of the marshy 

 country from Dhoobri to Gwalpara and on to Tezpur all 

 testify to the same continuous depression here. It is 

 exactly north of this that we find the Sivalik formations 

 absent at the base of the Himalayas, and we have the evi- 

 dence of exclusively marine conditions in pliocene times at 

 the base of the Garo Hills. 



\Vc find also a large development of marine beds above 

 the nummulitic limestone in the Jaintia country, passing 

 up conformably into a great thickness of upper miocene 

 sandstone of the Burrail range. In such sandstone, north 

 of the IVIunipur valley, the only fossils found were marine 

 forms. This Ljiiulual depression of the delta of the (ianges, 

 the relati\e liighcr level of the water-parting and shifting 

 of the Punjab rivers westward, appear to be only the last 

 phase of that post-pliocene disturbance which broke up the 

 Assam sub-Himalayan lucustrine system draining into the 

 Arabian Sea. Zoological evidence is also in favour of this 

 former connection of the now-separated waters of the 

 Ganges and Indus basins, and the hill tracks of the Garo 

 and Khasi Hills with pcsninsular India. The ground 

 where the miocene rocks are absent is not where any de- 

 nuding force from the north could have acted with any 

 abnormal intensity. It lies under the hills, where no great 

 tributary enters the plain, and might have removed the 



above formation. All the evidence is in favour of the 

 axis line of depression in the Ganges delta between 

 Rajmahal and the Garo Hills extending thus far, and 

 that the miocene beds, once continuous, are li-, re thus lost 

 to sight beneath the more recent yet extensi\e graveis and 

 conglomerates that here occur, and have partaken also of a 

 last slight elevation of the mountain cliain. 



Great lateral rolls or waves of the stratified rocks occur 

 at intervals all along the southern line of the chain, and 

 apparently have a connection with the transverse drainage 

 lines. Within the mountains in the old rock basins — and 

 these are analogous to the valleys of the Alps — are pliocene 

 and post-pliocene beds of great thickness, but of fresh- 

 water origin ; the remnants of which are to be seen in 

 Kashmir and Scardo at intervals, along the valley of the 

 Indus, and that large — now elevated — accumulation at the 

 head of the Sutlej River in Hundes, first brought to notice 

 by the labours of Captain (now General) R. Strachey. The 

 remnants of these deposits in Kashmir and Scardo are 

 found preserved in the more sheltered portions of the 

 valley basins, untouched by the denuding action during 

 the glacial period — the exponents presented to us of the 

 enormous denudation that went on during the post-pliocene 

 times, of which the glacial period formed a part. 



The extent and displacement of the upper pliocene beds 

 is in North Italy and here very similar. Often abutting 

 horizontally against the mountains, they are in other 

 places found tilted at a considerable angle on the margin of 

 their original extension. 



When we examine their contents, we find that the fauna 

 of that time in Asia, as well as in Europe, was more 

 African in character, and genera now confined to that 

 continent were abundant far to the north. The sluggish 

 rivers and lakes of Sivalik times in Asia and of the corre- 

 sponding period in Europe were the home of the hippo- 

 potamus, crocodiles, and tortoises, of which the common 

 crocodile, the gavial or long-snouted species, and an emys 

 have survived the many geological changes, and still 

 inhabit the rivers and low grounds of India to-day. The 

 fresh-water shells are still the same now as then. Many 

 species of antelope lived in the neighbouring plains and 

 uplands ; the elephant was there in the zenith of its 

 existence, for no less than thirteen species have been found 

 fossil in Northern India ; but it is impossible in a short 

 address to enumerate the richness of this fauna, and the 

 extreme interest that surrounds it. 



(To 5e continued.) 



Electricity for Picnic Parties. — It is stated that the 

 Cumberland Valley Railway Company has built an electric 

 light car, which will be used to supply the electric light to 

 picnic parties along the line. 



Small-Wheeled Tricycles. — What can be done on 

 small-wheeled bicycles has just been proved by the per- 

 formance of Mr. Adams, who, riding a 4 1-inch " Facile " 

 bicycle, started at midnight, Friday, Sept U, from a 

 point one mile beyond Barnet, on the Hatfield-road, and 

 rode through Ilitchin, Biggleswade, Bedford, St Neots, 

 Cambridge, and Huntingdon, returning by the same road 

 to Hitchin, and went on to Langford, which" he reached at 

 midnight on the Saturday, having covered a distance of 

 2-11.', miles in the 'J I hours. The roads were in many 

 places heavy with wet, and some time was lost on the way. 

 Had it not been for these dillieulties over 250 miles would 

 certainly have been accomplished. Messrs. Larrettc and 

 Barrow, in accompanying Mr. Adams from Cambridge to 

 St Neots, rode the It* miles in 25 minutes, a splendid 

 piece of road-riding on a tricycle. 



