Extremities:  Geology and Life in Yellowstone and Implications for Other Worlds


Twin Buttes View spring seems typical of the small hot springs on the upper and back terraces of the Mammoth Hot Springs complex. TB View and similar springs are not terribly hot, and have near-neutral waters, but are very rich in hydrogen sulfide gas and dissolved carbonate. The carbonate precipitates out as the spring waters lose their sulfur and become less acidic (lower pH). Most of the springs at Yellowstone deposit silica, which is dissolved out of the Yellowstone volcanic rocks. The Mammoth Hot Springs are outside the Yellowstone volcanic caldera, so the water has been able to dissolve carbonate from the limestones in the basement rock. The source of the carbonate is probably the Madison Limestone (Mississippian age) which is similar to the Redwall Limestone of the Grand Canyon.

BL View Spring 1
BL View Spring 2

The main (eastern) source of TB View springs. Normal plants grow in the background, nourished by water that has lost its sulfur. We collected a mat sample for spectroscopy just to the right of this scene.
White microbial filaments, at the source of the TB View spring. These are probably Thiothrix, which makes its living by oxidizing hydrogen sulfide in the water. The sulfur ends up as little pearls of elemental sulfur (just like Chromatium) in their cells. The Thiothrix filaments look white because the sulfur pearls scatter light efficiently.
Sulfur test
Cool Spring

Colorimetric test for dissolved sulfur. Dr. Ward used a reagent that turns blue in the presence of dissolved sulfur (as sulfide). The tube on the right contains water from Octopus Spring, which is low-sulfur. The tube on the left contains water from the TB View spring, which is really rich in sulfur.
Water in the TB View spring is relatively cool, at 59°C, and very slightly acidic with pH = 6.8.

Next - TB View 2  |  Back to Workshop
Back to Extremeties: Geology and Life in Yellowstone
LPI home page | LPI Education Resources Page
Copyright Allan Treiman, LPI.
Updated 11/15/02.
Comments to webmaster@lpi.usra.edu.