Effect of the volcanic front migration on helium, nitrogen, argon, and carbon geochemistry of hydrothermal/magmatic fluids from Hokkaido volcanoes, Japan

Magma-derived CO 2 emissions in the Tengchong volcanic field, SE Tibet: Implications for deep carbon cycle at intra-continent subduction zone

“…Volatiles released by residual melts in magma chamber tend to be affected by calcite precipitation in hydrothermal system. (Graham, 2002;Sano and Fischer, 2013), OSZ (Sano et al, 1994(Sano et al, , 1998(Sano et al, , 2006Taran, 2009;Halldórsson et al, 2013;Jean-Baptiste et al, 2014;Roulleau et al, 2015b), CSZ (Shangguan et al, 2000;Xu et al, 2004;Zhao et al, 2011Zhao et al, , 2012Cheng et al, 2014) and CCZ (Yokoyama et al, 1999;Hoke et al, 2000;Zhao et al,2002;Walia et al, 2005;Newell et al, 2008;Klemperer et al, 2013;Zhang et al, 2014). (b) Comparison of Nd-Sr isotopes between mantle-derived magmas from MOR (Zindler and Hart, 1986), OSZ (GEOROC database), CSZ (Wang et al, 2006;Zou et al, 2014;Guo et al, 2015a) and CCZ (Guo et al, 2013(Guo et al, , 2015.…”

“…10a-b), air-corrected 3 He/ 4 He ratios of the TVF samples (0.21−5.92 R A ) are clearly lower relative to reference values for arc-related volatiles (7.4 ± 1.3 R A ; Sano and Fischer, 2013) and many typical OSZ samples [0.03−8.46 R A ; e.g., Kamchatka (Taran, 2009), Japan Arc (Sano et al, 1994(Sano et al, , 1998(Sano et al, , 2006Roulleau et al, 2015b), Sunda Arc (Halldórsson et al, 2013) and Lesser Antilles (Jean-Baptiste et al, 2014)]. Compared with MOR values (e.g.,…”

Contribution of deep-earth fluids to the geothermal system: A case study in the Arxan volcanic region, northeastern China

“…The calculated results indicated that more than 95% of N 2 and more than 91% of Ar in the gas samples were of no-atmospheric origin (Table 2). N 2 */Ar* ratios ranged from 52.21 to 88.04, less than those of geothermal gases in the volcanic arc (107-388 (Roulleau et al, 2015)) and mantle (350 (Taran, 2011)). The low N 2 */Ar* ratios can be attributed to the contribution of radiogenic Ar produced by 40 K that is relatively enriched in the granodiorite and alkaline basaltic rocks (Figure 1).…”

“…Nitrogen, in some instances, is the main component in hot spring, fumarole, and volcanic gases, which were identified as a mixture of atmospheric, mantle, and crustal N 2 (Roulleau et al, 2015;Tardani et al, 2016;Zhao et al, 2021). N 2 is the predominant component in the hot spring gases in the AVR, and δ 15 N values are in a range of +1.3-+1.9% (Table 2).…”

“…Isotopic ratios of noble gases in mantle xenoliths in the orogenic belt and rift valley indicate that the mantle in NE China is heterogeneous. Obviously, the geochemical characteristics of the mantle in NE China differ from those in the middle ocean ridge and volcanic arc (Sano and Marty, 1995;Shaw et al, 2003;Roulleau et al, 2015).…”