"Continental Smokers": evaluating mantle degassing, CO2 flux, geomicrobiology, and water quality in extensional continental regimes

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This study challenges a widespread notion that most global CO2 degassing takes place at mid-ocean ridges and subaerial volcanoes by evaluating degassing in continental extensional areas. The hypothesis to be tested is that there is a substantial and unrecognized upward flux of fluids and gases from deep within the earth that rise through vents in the Rio Grande rift and other tectonically-active regions of the western U.S. These fluids often issue as carbonate-depositing (travertine) springs, degrade regional water quality, release carbon to the atmosphere, and support distinct microbial ecosystems. This study will gather data on time-variations in the geochemical character (including trace element, stable isotope and noble gas analysis) of major spring systems and associated groundwaters to evaluate a hypothesis that microseismicity is triggering advective transport and degassing. Microbial sampling and DNA amplification will be used to compare these ?continental smokers? to black and white smokers known along oceanic spreading centers. The study will support graduate and undergraduate training, as well as a museum exhibit on travertine springs and their geological and hydrologic significance.