Microbial Impacts on Geothermometry Temperature Predictions

Abstract

Conventional geothermometry approaches assume that the composition of a water sample collected near the surface but with origins in a deep geothermal reservoir still reflects chemical equilibration with the deep reservoir rocks. However, for geothermal prospecting samples whose temperatures have dropped to 5 orders of magnitude. The assay was applied to DNA extracted from water collected at surface springs located in and around the town of Soda Springs, Idaho. These springs produce water that is believed to be a mixture of groundwater and deep hydrothermal fluids. The qPCR results indicated that sulfate reducing genes were present in each of the samples tested, and consideration of the microbiological results together with geothermometry calculations suggests that microbial metabolism can influence reservoir temperature predictions.