Figure 3
From: Arima hot spring waters as a deep-seated brine from subducting slab
δ18O versus δD diagram of the Arima hot spring waters and the predicted δ18O-δD evolution lines of slab-derived fluids. Red and green lines represent the evolution lines as a function of depth for the Philippine Sea slab (beneath southwestern Japan) and the Pacific slab (beneath northeastern Japan), respectively. The solid circles along the evolution lines indicate depth with intervals of 10 km. Red open star represents δ18O and δD of seawater, which is defined as 0‰ standard mean ocean water (SMOW). Blue open star at δ18O and δD ~ (+8,-40) represents the initial values of altered oceanic crust (AOC) just before subduction (Muehlenbachs 1986; Kawahata et al. 1987). Solid black line in the negative δ18O field represents the average meteoric water line in Japan (Masuda et al.1985). Large purple circle labeled ‘Magmatic water’ represents the reported range of the worldwide δ18O and δD of magmatic fluids, fumarolic gases, and andesitic waters after White (1957), Matsuo et al. (1974), Sakai and Matsubaya (1977), Mizutani (1978), and Giggenbach (1992).