Using Geochemistry and Geomorphology to Understand the Evolution of a Hot Spring System
Description
The Greater Obsidian Pool Area just south of the Mud Volcano area in Yellowstone National Park is an active and ever-changing hot spring region. Situated next to a lake in a meadow between several hills of glacial deposits, north of the Elephant Back rhyolite flow, a diverse group of hot springs has been developing. This study examines the geologic and geomorphic context of the hot springs, finding evidence for a previously undiscovered hydrothermal explosion crater and examining the deposits around the region that contribute to properties of the groundwater table. Hot spring geochemical measurements (Cl- and SO4-2) taken over the course of 20 years are used to determine fluid sourcing of the springs. The distribution of Cl-, an indicator of water-rock interaction, in the hot springs leads to the theory of a fissure delivering hydrothermal fluid in a line across the hot spring zone, with meteoric water from incoming groundwater diluting hot springs moving further from the fissure. A possible second dry fissure delivering mostly gas is also a possible explanation for some elevated sulfate concentrations in certain springs. The combination of geology, geomorphology, and geochemistry reveals how the surface and subsurface operate to generate different hot spring compositions.
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2022-05
Agent
- Author (aut): Alexander, Erin
- Thesis director: Shock, Everett
- Committee member: Whipple, Kelin
- Contributor (ctb): Barrett, The Honors College
- Contributor (ctb): School of Earth and Space Exploration
- Contributor (ctb): School of Molecular Sciences