Isotopic Analysis At U.S. West Region (Welhan, Et Al., 1988)
Exploration Activity: Isotopic Analysis At U.S. West Region (Welhan, Et Al., 1988)
|Exploration Activity Details|
|Location||U.S. West Region|
|Exploration Technique||Isotopic Analysis- Fluid|
Helium isotope ratios are not correlated with regional heat flow in the western United States. High helium isotope ratios (R/RA > 2) occur only in magma-based geothermal systems. A direct correlation exists between geothermal reservoir temperature and helium isotope ratio of the fluids, suggesting that both heat and helium in a geothermal reservoir are derived from a shallow magmatic source. The rapid lateral decrease in 3He away from such systems indicates that high helium isotope ratios are a local manifestation of magma emplacement and hydrothermal convection.
- J. A. Welhan, R. J. Poredai, W. Rison, H. Craig (1988) Helium Isotopes In Geothermal And Volcanic Gases Of The Western United States, I, Regional Variability And Magmatic Origin