Mass spectrometer measurements in the thermal areas of New Zealand: Part 1. Carbon dioxide and residual gas analyses
Mass spectrometer measurements have been made on carbon dioxide and residual gases in some thirty geothermal bores, fumaroles and pools in New Zealand. With one exception, the A 40/A 36 ratio in the discharges show the argon to be of atmospheric origin. Consideration of argon to water ratios appears to confirm the hypothesis that loss of gas occurs underground in some areas. The argon to nitrogen ratios which were lower than the 2.7/100 value expected from heated ground water, suggest an alternative source of nitrogen. The excess nitrogen appears to be related to the total hydrogen content by a square law. The underground temperatures calculated assuming chemical equilibrium between carbon dioxide and methane are given in some cases and are in reasonable agreement with bore measurements.