GEOLOGICAL SKETCH 291 



beds of chalk. At length it rises above the receding 

 waters and again appears above the surface. For an 

 unknown period it stands exposed, worn by subaerial 

 action into all the varied shapes that mark the form of 

 the land. 



Again it subsides. A third time the waters return 

 and the Cretaceous land sinks deeper beneath their 

 flow. Shales and limestones are again formed in the 

 depths, while the bed of the sea swarms with countless 

 nummulites. In the chalky deposit they are small 

 and not so numerous, but when the sea grows more 

 shallow and the darker silt settles in its bed, then the 

 nummulites flourish and with their own dead bodies 

 build up the thickness of the future stone. It is the 

 Eocene period, and the main bulk of the limestone 

 hills is being slowly laid down. 



Then comes the great upheaval, the period of 

 mountain-building. The Central Asian sea again 

 recedes. The molten granite lying dormant beneath 

 the sediments wells upward into the overlying beds. 

 It intrudes into the slates, crushing and crystallizing 

 them and forcing upwards into crustal folds all those 

 vast deposits. Slowly, perhaps a few inches a year, 

 they rise upwards through the sea, and for the last time 

 Hazara emerges from the ocean. The rain denudes 

 them, rivulets erode them, and, as they rise higher 

 into the heavens, the snows and glaciers mould them 

 into rugged ranges. Sediments are swept away from 

 their summits, and in the great peaks the intrusive 

 granite is laid bare. Upheaving, fracturing and 

 shaking the earth's crust, the Himalaya has slowly 

 risen from the sea, and from the gentle earthquakes 

 that almost monthly shake Hazara, it seems as though 



U 2. 



