A small mudpot vent in Pocket Basin at the north end of Yellowstone's Lower Geyser Basin produced this intriguing feature that mimics a spatter cone that issued a lava flow. Mudpots form in areas of intense, clay-rich hydrothermal alteration where the thermal system is dominated by gases.

Photo by Dan Dzurisin, 1983 (U.S. Geological Survey).

This image is made available as a Public Domain Work, but proper attribution is appreciated.

Galleries: Geothermal Features

Keywords: geothermal | mud pool

Yellowstone