"Volcanic vents" refers to openings or cracks on the Earth's surface through which molten lava, gas, and other volcanic materials are released during a volcanic eruption. Full definition
You will travel over several miles of black stone and crushed rock towards volcanic vents. (tropicalhelicopters.com)
Life on Earth likely emerged in the deep ocean, where simple organisms fed off toxic gas from volcanic vents. (discovermagazine.com)
As it turned out, they were feeding on bacteria that got their energy from hydrogen and hydrogen sulfide emanating from underwater volcanic vents. (extremetech.com)