Fumaroles

Matsuo, S. (1961) On the chemical nature of fumarolic gases of Showashinzan Volcano, Hokkaido, Japan. J. Earth ScL Nagoya U., 9, 80-100. 

Mizutani, Y. and Sugiura, T. (1982) Variations in chemical and isotoic compositions of fumarolic gases from Showashinzan volcano, Hokkaido, Japan. Geochem. J., 16, 63-71. 

Sano and Williams (1996) calculated present-day volcanic carbon flux from subduction zones to be 3.1 x 10 mol/year based on He and C isotopes and C02/ He ratios of volcanic gases and fumaroles in circum-Pacific volcanic regions. Williams et al. (1992) and Brantley and Koepenich (1995) reported that the global CO2 flux by subaerial volcanoes is (0.5-2.0) x lO mol/m.y. and (2-3) x 10 mol/m.y. (maximum value), respectively. Le Guern (1982) has compiled several measurements from terrestrial individual volcanoes to derive a CO2 flux of ca. 2 x 10 mol/m.y. Le Cloarec and Marty (1991) and Marty and Jambon (1987) estimated a volcanic gas carbon flux of 3.3 X 10 mol/m.y. based on C/S ratio of volcanic gas and sulfur flux. Gerlach (1991) estimated about 1.8 x 10 mol/m.y. based on an extrapolation of measured flux. Thus, from previous estimates it is considered that the volcanic gas carbon flux from subduction zones is similar to or lower than that of hydrothermal solution from back-arc basins. 

Helens emissions An estimation of the magma reservoir volume. J Volcanol Geotherm Res 28 85-89 Le Cloarec M-F, Allard P, Ardouin B, Giggenbach WF, Sheppard DS (1992) Radioactive isotopes and trace elements in gaseous emissions from White Island, New Zealand. Earth Planet Sci Lett 108 19-28 Le Cloarec M-F, Pennisi M, Corazza E, Lambert G (1994) Origin of fumarolic flnids emitted from a nonerapting volcano Radionuchde constraints at Vulcano (Aeolian Islands, Italy). Geochim Cosmochim Acta 58 4401-4410... 

The report by Yamagata et al. (1991) that acid basalts, i.e., those with a high SiC>2 content, can set free P4O10 from their apatite component if heated to 1,470 K, appears important. They found concentrations of around 5pM pyrophosphate and tripolyphosphate in a fumarole in the neighbourhood of the strato-volcano Uzo on... 

Yamashita, K., H. Yoshikawa. M. Yanaga, K. Endo, and H. Nakahara, Determination of 220Rn and 222Rn Concentrations in Fumarolic Gases, this volume (1987). 

A radiochemical method for the determination of Rn-220 in fumarolic gas is studied. Both condensed water and non-condensing gas are collected together and Pb-212 is precipitated as PbS. After dissolving the precipitate in conc.HCI, it is mixed with an emulsion scintillator solution for activity measurements. As Pb-214 is simultaneously measured, the observed ratio of Pb-212 /Pb-214 gives Rn-220/Rn-222. This method is superior to the method of directly measuring Rn-220 for the samples in which Rn-220/Rn-222 ratios are less than unity. This method and the previously proposed direct method were applied in the field, and new data obtained. An attempt was also made to understand the formation and transport of radon underground. 

The Rn-222 concentrations in the soil gas, fumarolic gas, atmosphere, and in the underground water have been measured extensively for the studies of seismology, uranium mining, environmental science and geochemistry. It has been known that its concentrations are often very high in fumarolic gases and in the underground water, the reason for which is, however, not clarified yet. 

In the present work, an indirect method for the determination of Rn-220 in fumarolic gases has been studied that measures essentially the activity of Pb-212, the progeny of Rn-220, together with a further investigation on Rn-220 and Rn-222 concentrations at various sites. 

Formation and transport of radon ) In the present work, lead isotopes were chemically separated from the sample gas as lead sulfide since the formation of lead sulfide was inevitable under the presence of H2S in the fumarolic gas. The lead sulfide was then dissolved in a small amount of concentrated HCI and mixed with the Insta Gel(emulsion scintillator solution, Insta Gel, Packard Inc.) for the liquid scintillation counting. The chemical yield and the volume of the collected non-condensing gas were obtained from the measurement of the activities of Pb-214 and its progeny which were in radioequilibrium with their precursor Rn-222 whose concentration was determined separately by the direct method. 

Naughton, J. J., Lee, J. H., Keeling, D., Finlayson, J. B., Dority, Helium flux from the earth s mantle as estimated from Hawaiian fumarolic degassing, Science, 180, 55-57 (1973). 

Figure 6. Stable-Cl isotopic composition of fumarolic minerals, volcanic gas condensates and geothermal waters. Bracketed numbers correspond to references listed in Figure 3, Figure 4, and, [18] Wahrenberger et al. 1997 [19] Godon et al. 2004 and [20] Kaufmann 1989.

Giggenbach W. F. (1987). Redox processes governing the chemistry of fumarolic gas discharges from White Islands, New Zealand. Appl Geochem., 2 143-161. 

The volcanic sublimates ", such as sulfur, ammonium chloride, arsenic sulfide, copper chloride, magnetite, may be mentioned in this connection, as well as the minerals accompanying fumarole and hot-spring activity. 

Since Ramsay and Travers discovered neon in the most volatile portion of their argon (69), this immediately established the occurrence of neon in the atmosphere. In 1909 Armand Gautier showed that the fumaroles of Vesuvius and the gas which bubbled from the hot springs in an old crater at Agnano, near Naples, contained neon (69, 77). 

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