Mudpots are natural phenomena that one can see in very few places like the yellow stone national park, few geothermal sites of Iceland and New Zealand. Mudpot is nothing but a pool of hot mud that is bubbling.
Mudpot doesn’t form everywhere and forms only under certain conditions. It generally occurs where there is some surface water which has no direct connection to the ground water. The surface water becomes an impermeable depression due to a lining of clay beneath it. Presence of hydrogen sulfide gas inside the ground is important for the formation of mudpots.
Very much below this depression, the presence of hot water causes steam to raise through the ground which heats up the surface water. The hydrogen sulfide gas acts as source of energy for the micro organisms present under the ground. The micro organisms convert the hydrogen sulfide into sulfuric acid. The sulfuric acid thus produced breaks and corrodes the surrounding soft rocks into clay. This results in mudpots taking the form of smelly, thick slurry-like mixture through which gases bubble out. A rotten egg smell is produced by mudpots due to hydrogen sulfide.