118 FORESTRY IN BRITISH EAST INDIA. 



Sikkim. To the east of this point the drainage goes into the 

 Bramaputra. The drainage of the Peninsula is arranged in the 

 following manner : — The Ganges receives the drainage of the 

 northern edge. Next, two rivers, the Narbada and Tapti, run in 

 close proximity in a western direction into the Arabian Sea. A 

 series of short streams run from the Western Ghat to the sea, 

 but by far the greater portion of the plateau sends its water in an 

 eastern direction into the Bay of Bengal, because the highest part 

 of the Peninsula is close to the sea on the west. 



The two principal rivers in Burma are the Irawadi and the 

 Salween. A third river, the Sittang, runs between the two. 

 They run from north to south, but the Salween also takes in a 

 large feeder, the Thaungyin, which comes from the south-east. 



2. Geology and Soils. 



The peninsula is one of the oldest formations on the earth and 

 the Himalayas one of the most recent. The rising of the latter, 

 apparently, caused the formation of the Indo-Gangetic plain, as 

 well as that of the Assam valley. In the peninsula, crystalline 

 schists, gneisses and plutonic rocks are common. These old 

 formations have withstood folding, the features of the land being 

 the result of differential erosion. In many parts they are covered 

 by various systems known as the GwaHors, Vindhians, Cuddapahs 

 and Kurnools. The rocks of the last three are chiefly sandstones, 

 shales and limestones. No marine fossils are found in them. At 

 a later period these formations were covered over an area of 

 200,000 square miles in Bombay, the Central Provinces, Berar 

 and Hyderabad by volcanic ashes and lava, in some places to a 

 depth of 6,000 feet. These deposits are known as the Deccan trap. 



The rest of India belongs to a later geological period ; 

 the rocks south of the Himalayan snowy range bear no fossils. 

 When the Himalayas rose, the sea alternately receded from Upper 

 India and Burma, and submerged again part of the country ; 

 hence fossiliferous rocks of marine origin are common, the oldest 

 being the Salt Range in the Punjab. Quarzite, shales, slates, 

 dolomite, limestone, conglomerate, granite and sandstones are 

 among the rocks in the Himalayan north-west frontier, Assamese 

 and Burmese regions, eruptive action being apparent in Balu- 

 chistan and Burma. Towards the foot of the Himalayas, no 



