Geochemistry of low-temperature springs northwest of Yellowstone caldera: Seeking the link between seismicity, deformation, and fluid flow

Journal of Volcanology and Geothermal Research
By: , and 

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Abstract

A comprehensive geochemical survey of springs outside the northwest margin of the Yellowstone caldera was undertaken in 2003 and 2004. This survey was designed to detect: (1) active leakage from a huge reservoir of CO2 gas recently postulated to extend from beneath the caldera into this area; and (2) lingering evidence for subsurface flow of magmatic fluids into this area during the 1985 seismic swarm and concomitant caldera subsidence. Spring temperatures are low (< 15 °C), but two large-discharge springs contain 14C-dead carbon that can be identified as magmatic from calculated end-member values for δ13C(dead) and 3He/C(dead) of − 4‰ and 1 × 10− 10, respectively, similar to values for intra-caldera fumarolic and hot-spring gases. However, the combined discharge of magmatic C is only 5.4 tonnes/day, < 0.1% of the total output from Yellowstone. The two springs have slightly elevated 3He/4He ratios near 1 RA and anomalous concentrations of Cl, Li, and B, and appear to represent minor leakage of gas-depleted, thermal waters out of the caldera. The small CO2 signal detected in the springs is difficult to reconcile with a large underlying reservoir of gas in faulted and seismically active terrain. When considered with analyses from previous decades, the results provide no evidence to associate the ten-year period of caldera deflation that began in 1985 with expulsion of magmatic fluids through the caldera rim in this area.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Geochemistry of low-temperature springs northwest of Yellowstone caldera: Seeking the link between seismicity, deformation, and fluid flow
Series title Journal of Volcanology and Geothermal Research
DOI 10.1016/j.jvolgeores.2006.01.001
Volume 154
Issue 3-4
Year Published 2006
Language English
Publisher Elsevier Science
Contributing office(s) Toxic Substances Hydrology Program, Volcano Hazards Program
Description 12 p.
First page 169
Last page 180
Country United States
State Montana, Wyoming
Other Geospatial Yellowstone National Park
Online Only (Y/N) N
Additional Online Files (Y/N) N