I thought this was very fascinating:
The world's oldest water, which is locked deep within the Earth's crust, is present at a far greater volume than was thought, scientists report.
The liquid, some of which is billions of years old, is found many kilometres beneath the ground.
Researchers estimate there is about 11m cubic kilometres (2.5m cu miles) of it - more water than all the world's rivers, swamps and lakes put together.
It means that great swathes of the deep crust could be harbouring life.http://www.bbc.com/news/science-environment-30527357
