Geofluids Assessment of the Ayub and Shafa Hot Springs in Kopet-Dagh Zone (NE Iran): An Isotopic Geochemistry Approach

Table 2

Temperatures and depths of hydrothermal reservoirs for AP and SH hot springs, calculated based on Na-K geothermometers [28, 31], Aq.QA hydrochemical software [21], and isotopic method.

	Ayub Peighambar hot spring					Shafa hot spring
	Sp8.1	Sp8.2	Sp8.3	Sp8.4	Sp8.5	Sp10.1	Sp10.2
Using Aq.QA hydrogeochemistry software
Temperature (Na-K)	<150	<150	<150	<150	<150	<150	<150
Depth (km)	<5	<5	<5	<5	<5	<5	<5
Depth (km)	4.65	4.65	4.65	4.65	4.65	4.65	4.65
Using Mohammadi’s [31] method
Temperature (Na-K)	113	114	114	110	111	101	101
Depth (km)	3.76	3.80	3.82	3.66	3.70	3.36	3.36
Depth (km)	3.42	3.45	3.47	3.31	3.35	3.02	3.02
Isotopic method (all isotope data in VSMOW)
	In cold spring	In hot spring	Difference (Δ)				Max depth (km) of water circulation
δ^18O	−9.29	−9.97	−0.68				4.16
δ^2H	−66.47	−73.0	−6.53				3.66

Based on general law of geothermal gradient (30°C/km).
Using Marques et al. [32] approach.