Original composition and formation process of slab-derived deep brine from Kashio mineral spring in central Japan

Earth, Planets and Space

Table 2 Chemical and isotopic compositions of the estimated KDE, the Arima brine end-member, and fluid inclusions within metamorphic rocks in a subduction zone

	Temperature, °C	pH	Na, mg/L	K, mg/L	Mg, mg/L	Ca, mg/L	Cl, mg/L	HCO₃, mg/L	SO₄, mg/L	Li, mg/L	Br, mg/L	Br/Cl, molar ratio, × 10⁻³	δD, ‰	δ¹⁸O, ‰	References
KDE	12	7.8	14,000	180	66	650	24,000	66	0	83	41	0.75	− 52	− 2	Present study
Arima end-member	>138	–	25,900	5250	0.09	5020	54,000	–	–	78	115	0.92	− 32	10	Masuda et al. (1985)
Arima end-member	–	–	21,000	3700	–	3100	42,000	–	–	55	84	2.0	− 33	6	Kusuda et al. (2014)
Fluid inclusions	–	–	–	600 ~ 3700	–	–	12,000 ~ 240,000	–	–	–	27 ~ 2000	1.0 ~ 3.7	–	–	Kendrick et al. (2011)
Fluid inclusions	–	–	5400 ~ 53,000	1100 ~ 57,000	N.D. ~ 20,000	N.D. ~ 16	–	–	–	N.D. ~ 49	–	–	–	–	Fukuyama et al. (2017)

KDE is extrapolated as described in the text. The composition of the Arima brine end-member is from Masuda et al. (1985) and Kusuda et al. (2014), and those of fluid inclusions are from Kendrick et al. (2011) and Fukuyama et al. (2017)