Scientists from the National Oceanography Centre in Southampton made the discovery in the Cayman Trough in the Caribbean using a remote-controlled robot submarine.
They discovered slender spires made of copper and iron ores.
The water being pumped out from of the so-called “black smokers” is hot enough to melt lead.
The area is almost half a mile deeper than has ever been seen before and, with extremely high water pressure, it is tantamount to a “hell on Earth”.
The boiling water that gushes out from deep-sea vents helps to nourish colonies of marine creatures.