Shrugs going through chemical weathering at Mammoth Hot Springs.
Mammoth Hot Springs composes of the most extensive system of actively forming hot springs terraces within the park. These terraces are made up of travertine: dissolution of limestone (or calcium carbonate) deposits from thermal water. Limestone lives in the fault lines along Mammoth Hot Springs, which draw conclusions of how the network of hot springs formed over vast topography.
The precipitation of limestone propels the odor of rotten eggs. Photosynthetic bacteria actively breaking down the hydrogen sulfide in the water and creating Calcium Carbonate. The bacteria produce vibrate colors of yellows, oranges and browns as seen in the ionic images of Yellowstone's geothermal features. Prolific Calcium Carbonate is actually suffocating Lodgepole Pine Trees, found all around Mammoth Hot Springs.
|The Southern view of Obsidian Cliff by Joseph Iddings 1888.|
Eleven miles south of Mammoth Hot Springs is Obsidian Cliff. The USGS Map of Geological Yellowstone indicates the unique rhyolite formations. Obsidian rock forms from rapidly cooling lava that has no crystallization, resulting in a dark volcanic glass. The photo above shows columnar joints, lava flow cooled and contracted as a single unit, in a rapid pace. The joints weaken the rock for erosion to occur. Add steep slope to form a talus slope of scree. Obsidian occurs naturally as small rocks, making Obsidian Cliff rare as its vast expansion of the volcanic glass. Archeological artifacts show many cultures used Obsidian for tools, such as Native Americans making arrowheads.
|Enlarged map of the geological formations of Obsidian Cliff. The (Qpr) amaranth formation is the plateau and the pastel yellowstone (Qs) detrital deposits.|
|(A) Confined pressure (B) water Table drops, which fragments the overlying rock and propels it upward (C) explosion of mud, steam, and water until a drop in confining pressure and steam lessened (D) a crater remains and fills with water.|
|Soil profile of Mary Bay, Yellowstone Lake (Click to enlarge)|