f 24 ] 



23. The following summary of the geological strata as 

 they particularly refer to India may be found useful : 



A. NEO-ZOIC. 



1st. Recent. Blown sands,* alluvium, fluvitile and marine, including 

 deltas and lagoons, laterite and gravels. Example, the united 

 Delta of the Ganges and the Brahmaputra covering a space of 

 50,000 to 60,000 square miles and a depth of about 500 feet, and 

 the whole of the Indo-Gangetic Basin. General character, fine sands 

 and clay with occasional pebbles or pebble-beds, beds of peat and 

 remains of trees, but no trace of marine organism. 



2nd. Pleistocene or Glacial period. Erratic boulders and moraines in tr?e 

 Himalayas and Upper Punjab. Modern fauna. 



3rd. Pliocene period. Soft massive sandstone also clays and conglomerates, 

 all fresh water, resting on the Nummulitic limestones. Example, 

 Siwalik-beds, full of fossil remains of animals, chiefly mammals allied 

 to modern fauna ; also in Scind.the Punjab, the North- West- Provinces 

 of India, also along a narrow strip of hills from the Jhelum to the 

 Brahmaputra in the Sub-Himalayan region, 1,500 miles long and 

 12 to 15,000 feet in thickness. 



4th. Miocene. Marine sands, shales, clays with gypsum, sandstones and 

 highly Fossiliferous bands of limestones. Uppermost beds are clays ' 

 with Gypsum containing estuarine shells. This period is represented 

 in Scind. 



^th. Eocene. Sandstones probably fresh water ; also marine limestones 

 passing into sandstones and shales; Nummulitic limestones; clays 

 with Gypsum and Lignite abounding in marine fauna. Examples in 

 Scind, the Punjab, Assam and Burmah. 



B. MESO-ZOIC. 



6th. Cretaceous or Chalky system 1 7,000 feet. Here and there in the 

 Himalayas especially in Assam, but all over the Indian Peninsula 

 where it is covered over in the middle and east by the Deccan 

 Basalt which is the volcanic lava of this period. 



.Jth. Oolitic proper. Ammonite and Bellemnite of the Hima- 

 layas in Himalayan shales and limestones. 

 1 8th. Jurassic. Rajmehal hills (Characterised by Fossil 

 OOLITIC < plants) and Upper Panchet Series. 



4,500 FEET. I Qth. Liassic. Shales and Limestones of the Himalayas. Lower 

 beds of the Rajmehal hills and the Lias of India belong 

 ^ to the Gondwana system. 



10th. Triassic Lower Panchet Series of the Damuda Valley showing re- 

 2,300 feet. mains of Labyrinthodon reptiles, also Valleys of the 

 Central Provinces and of North-West Himalayas, where 

 they attain to a thickness of 1,000 to 2,000 feet chiefly in 

 North Kashmir and the Salt range of the Punjab. The 

 Fossils are like those of the Alpine Trias. Belong to 

 the Gondwana system. 



It should be noted that (i) Clay, (2) Sand, (3) Gravel, (4) Peat, (5) Shell- 

 marl and (6) Marine ooze of recent formation are analogous to (i) Shale, (2) 

 Sandstone, (3) Conglomerate, (4) Coal, (5) Limestone and (6) Chalk of old 

 geological formations. The older the sedimentary rocks the more compact 

 thty are. But their age is determined chiefly by fossils. 



