Geologists believe that about 10 crore years have passed once Jammu and Kashmir valley that was once a lake called Satisar,
The lake of goddess Sati, came into its present form. For hundreds of million years Jammu and Kashmir valley remained underneath Tethya sea and therefore the high sedimentary-rock hills seen in the valley now were once below water.
Geologists have come to believe that Jammu and Kashmir valley was earlier affected by earthquakes. Once there was such a devastating earthquake that it bust open the mountain wall at Baramulla. And therefore the water of the Satisar lake flowed out leaving behind lacustrine mud on the margins of the mountains known as karewas. Thus came into existence the oval but irregular Valley of Jammu and Kashmir.
The karewas being, in fact, the remnants of this lake confirm this view. The karewas are found largely to the west of the river Jhelum where these table-lands attain a height of about 380 meters on top of the level of the valley.
These karewas protrude towards the east and look like tongue- shaped spurs with deep ravines. Ancient legends and widespread traditions say that Samdimat Nagar, capital of the kingdom of Sundra Sena, was submerged as a results of an earthquake, and therefore the water that stuffed the area shaped the Wular Lake, the biggest freshwater lake in India.
The oldest igneous rocks are still found at Shankaracharya hill. when the whole valley of Kashmir was under water this hill was the primary piece of dry land lying in the form of an igneous island.