Origin of methane-rich natural gas in Japan: formation of gas fields due to large-scale submarine volcanism

Wakita, Hiroshi; Sano, Yuji; Urabe, Akiko; Nakamura, Yuji

doi:10.1016/0883-2927(90)90002-m

Cited by 51 publications

(29 citation statements)

References 39 publications

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“…Observed 3He/4He and 4He/20Ne ratios of 21 samples collected throughout the Hokkaido Island in this study as well as already published data Wakita et al, 1988) are shown in Table 1 together with the loca tion, the temperature, and the flow rate of water. Sampling sites and geotectonic configurations are shown in Figure 1.…”

Section: Resultsmentioning

confidence: 59%

Helium isotope ratio and heat discharge rate in the Hokkaido island, Northeast Japan.

Sano

Wakita

1988

Geochem. J.

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We have collected 21 gas samples of various kinds such as volcanic gas, hot spring gas and CH4-rich natural gas in the Hokkaido Island. Helium and neon in the samples were purified in a vacuum line and the 3He/4He and 4He/20Ne ratios were measured by a mass spectrometer. Observed 3He/4He and 4He/20Ne ratios vary significantly from 0 .242 x 10-6 to 9.58 x 10-6 and from 0.53 to 96, respectively.There is no correlation between the 3He/4He and 4He/20Ne ratios. Taking into account present data as well as published ones, geographical distribution of 3He/4He ratios indicates a clear contrast, high in the volcanic arc and low in the forearc region. The distribution pattern agrees well with the data of North east Japan and those of the North Island of New Zealand . Higher 3He/4He ratios than air in the volcanic arc region can be well explained by the presence of an uprising magma. Lower 3He/4He ratio in the forearc region is attributed to the radiogenic helium ac cumulated in crustal rocks. A positive correlation is found between the common logarithms of 3He/4He ratio and heat discharge rate of hot springs in the area. The tendency can be explained by a combination of magma aging and the dilution of magmatic fluids by local groundwater.

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Section: Resultsmentioning

confidence: 59%

Helium isotope ratio and heat discharge rate in the Hokkaido island, Northeast Japan.

Sano

Wakita

1988

Geochem. J.

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“…The estimated endmember δ 13 C values of the HAKUREI and JADE plumes is more 13 C-depleted than that in the Yonaguni Knoll fluid (~-27‰: Konno et al, 2006), slightly 13 C-enriched than those of 3 He-rich natural gases in north-east Japan (δ 13 C = ~-35‰, Wakita and Sano, 1983;Wakita et al, 1990). Notably, the estimated endmember δ 13 C values of the JADE plumes (-29~-31‰) are more enriched than those previously observed in the JADE fluid (-36~-41‰: Ishibashi et al, 1995).…”

Section: Carbon Isotope Ratio In Endmember Fluidmentioning

confidence: 99%

Gas geochemical characteristics of hydrothermal plumes at the HAKUREI and JADE vent sites, the Izena Cauldron, Okinawa Trough

et al. 2010

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“…Although bacterial oxidation of CH4 is possible to explain the heavy 813C signature of these samples and others, such as 6, 12, 15 and 23, we suggest that the high 813CCH4 values are also consistent with a trace origin of CH4 from a magmatic environ ment, similar to that noted for the White Island volcanic gases (Hulston and McCabe, 1962b). The ultimate source could be recylced crustal material (Marty and Jambon, 1987;Giggenbach, 1992a) or the mantle (Wakita et al, 1990). All but sample number 11 have 3He/4He ratios > 5 RA, indicating a mantle origin of the 3He.…”

Section: C02+4h2=ch4+2h2omentioning

confidence: 74%

“…1). In this study we specifically avoided CH4-rich natural gases from sedimentary basins, as they have been dis cussed before (Sano et al, 1983;Wakita et al, 1990). One necessity in choosing sample sites was the availability of springs with a free-gas discharge.…”

Section: Introductionmentioning

confidence: 99%

Carbon isotopes of methane and carbon dioxide in hydrothermal gases of Japan.

et al. 1993

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Terrestrial gas samples from thermal springs located along and behind the volcanic arc of Japan have a variable chemical and isotopic composition, largely reflecting their different positions with respect to a convergent plate boundary. The CO2 largely originates from subduction-related magmatism, though in N2-rich gases the CO2 may also have been derived from an organic sedimentary source. The chemical and isotopic compositions of the C02-CH4 pair indicate that both isotopic and chemical equilibrium are commonly attained (and maintained) in the C02-rich gases, whereas CH4 in the N2-rich gases appears to be affected by bacterial oxidation. In some samples with low contents of CH4, heavy 813CcH4 (-13 to -17%o) may result from quenching from magmatic conditions, though bacterial oxidation cannot be ruled out. In combination with the chemical composition of the thermal gases, no ble gas isotopic signatures indicate two sources: a magmatic source containing a mantle component and gases from melting of the subducting slab; these are mixed with atmospheric gases near the surface.

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Origin of methane-rich natural gas in Japan: formation of gas fields due to large-scale submarine volcanism

Cited by 51 publications

References 39 publications

Helium isotope ratio and heat discharge rate in the Hokkaido island, Northeast Japan.

Helium isotope ratio and heat discharge rate in the Hokkaido island, Northeast Japan.

Gas geochemical characteristics of hydrothermal plumes at the HAKUREI and JADE vent sites, the Izena Cauldron, Okinawa Trough

Carbon isotopes of methane and carbon dioxide in hydrothermal gases of Japan.

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