YELLOWSTONE NATIONAL PARK — On Saturday, Feb. 1, Scientist-in-Charge of the Yellowstone Volcano Observatory Mike Poland shared a video exploring Monument Geyser Basin and its underwater history.
According to Poland, Monument Geyser Basin sits near the edge of the Yellowstone Caldera surrounded by rock knowns as “Lava Creek Tuff,” an ash layer from about 631,000 years ago when the Caldera formed. Poland writes that acidic gas is circulating below the surface and visibly turning the ash layer into clay.
The monuments in Monument Geyser Basin are thought to have formed underwater, Poland writes. The most likely theory is that an ice-dammed lake was created in this area near the end of the last ice age, about 14,000 years ago, and hydrothermal venting from the bottom of the lake built the spires and chimneys. This is similar to how black smokers today on the ocean floor are venting hydrothermal fluids from chimneys.
“Here at the top of the hill, you get a view of what might actually be happening at the bottom of the ocean,” Poland says in the video.
