Left photo shows a loose piece of siliceous sinter that was precipitated around a photosynthetic microbial mat in the Lower Geyser Basin. The microbial mat died when the outflow channel changed positions. In the upper right, a Scanning Electron Microscope (SEM) image of siliceous sinter, with sheaths of silica that had precipitated around the once-living phototrophic microorganisms, making a texture that looks like cooked spaghetti. In the lower right, a closeup SEM image of the broken ends of those ‘spaghetti’ pieces, showing the hollow inside where there once was a bacterial filament that was part of a photosynthetic mat. The original bacterial filaments were about 1 µm in diameter, or about the diameter of a human hair.
People are also reading…
The geyser cones of Yellowstone are made up of material called sinter—a form of silica precipitated from hot water. When looking at the sinter under a powerful microscope, strange forms are revealed that are related to some of the earliest life forms on Earth.
When visiting Yellowstone National Park you may spend time exploring places where neutral to alkaline pH hot springs (those with pH values that are from around 7—or neutral—to approaching