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Generation and evolution of hydrothermal fluids at Yellowstone: Insights from the Heart Lake Geyser Basin

Geochemistry, Geophysics, Geosystems

By:
, , , and
DOI: 10.1029/2011GC003835

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Abstract

We sampled fumaroles and hot springs from the Heart Lake Geyser Basin (HLGB), measured water and gas discharge, and estimated heat and mass flux from this geothermal area in 2009. The combined data set reveals that diverse fluids share an origin by mixing of deep solute-rich parent water with dilute heated meteoric water, accompanied by subsequent boiling. A variety of chemical and isotopic geothermometers are consistent with a parent water that equilibrates with rocks at 205°C ± 10°C and then undergoes 21% ± 2% adiabatic boiling. Measured diffuse CO2 flux and fumarole compositions are consistent with an initial dissolved CO2 concentration of 21 ± 7 mmol upon arrival at the caldera boundary and prior to southeast flow, boiling, and discharge along the Witch Creek drainage. The calculated advective flow from the basin is 78 ± 16 L s−1 of parent thermal water, corresponding to 68 ± 14 MW, or –1% of the estimated thermal flux from Yellowstone. Helium and carbon isotopes reveal minor addition of locally derived crustal, biogenic, and meteoric gases as this fluid boils and degasses, reducing the He isotope ratio (Rc/Ra) from 2.91 to 1.09. The HLGB is one of the few thermal areas at Yellowstone that approaches a closed system, where a series of progressively boiled waters can be sampled along with related steam and noncondensable gas. At other Yellowstone locations, steam and gas are found without associated neutral Cl waters (e.g., Hot Spring Basin) or Cl-rich waters emerge without significant associated steam and gas (Upper Geyser Basin).

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Generation and evolution of hydrothermal fluids at Yellowstone: Insights from the Heart Lake Geyser Basin
Series title:
Geochemistry, Geophysics, Geosystems
DOI:
10.1029/2011GC003835
Volume
13
Issue:
1
Year Published:
2012
Language:
English
Publisher:
American Geophysical Union
Publisher location:
Washington, D.C.
Contributing office(s):
Volcano Science Center
Description:
20 p.; Q01017
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geochemistry, Geophysics, Geosystems
Country:
United States
State:
Wyoming
Other Geospatial:
Yellowstone National Park;Heart Lake Geyser