GEOLOGICAL SKETCH 289 



rich verdure that clothes the Tertiary rocks of the 

 district. 



Now that we have followed the rocky zones from 

 the central core of the Himalaya to the deposits of 

 Eocene times, let us glance for a moment at the story 

 they tell of the past history of this portion of the 

 earth. 



We must cast our mind back in thought to Palae- 

 ozoic times when a broad sea covered all Central Asia 

 and washed the northern shores of what is now the 

 Peninsula of India. A shore is a line of weakness in 

 the earth's crust liable to be raised into mountain folds, 

 and it was along the southern shores of that Central 

 Asian sea, where the waves lapped the northern coast 

 of India, that the Himalayan ranges were built up. 

 Few deposits are so little known as the sediments of 

 that ancient sea. When Thibet is opened to scientific 

 exploration more will be learnt of these deposits, for 

 the hills of that plateau are largely built up of its 

 sediments and are charged with the remains of living 

 creatures that once moved upon its bed. But our 

 ignorance is not complete, for here, over Hazara, there 

 flowed a little inlet of that sea, a narrow arm extending 

 southward, eating its way into the northern shores of 

 India and depositing those piles of sediment over 

 which we have just passed. 



Let us walk over the ground again. The slates 

 indicate the shallow waters of the Central Asian sea, 

 lying near to the ancient coast-line, depositing layer 

 upon layer of mud, and no doubt swarming with animal 

 life though all trace has disappeared. Here and there 

 the subordinate bands of limestone and conglomerate 

 tell how that ocean bed now deepened, now grew more 

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