The phrase "hydrothermal systems" refers to natural systems where hot water mixes with the Earth's crust. It often creates geothermal features like hot springs or geysers. Full definition
In addition, he notes, evaluating the fine structure of calcium carbonate mineralization deposited in hydrothermal systems during different periods of Earth's evolution may offer insights into which microbes lived at which times. (sciencemag.org)
«Because it is relatively cold, Lost City has been posited as a potential analogue of hydrothermal systems in active icy moons. (latimes.com)
Many distant worlds have never received as much light as Earth, but it is suspected that some of them have hydrothermal systems similar to Earth's deep - sea vents. (newscientist.com)