Studies of quaternary saline lakes-I. Hydrogen isotope fractionation in saline minerals
Borax, gaylussite, nahcolite and trona were synthesized in aqueous solution at temperatures ranging from 8° to 35°C. Except for borax, deuterium was always depleted in these hydrated minerals relative to the solutions from which they were crystallized. In borax, no significant fractionation was found. The fractionation factor of D H "> DH for the trona-water system exhibited a marked temperature dependence. By combining the deuterium contents of trona and the solution from which trona was crystallized, the following thermometer scale was obtained: In ( D H ) trona ( D H )water = 1.420 × 10 4 T 2 + 23.56 T "> (DH) trona(DH)water =1.420 × 104T2+23.56T (1) An attempt to establish a geothermometer based on C 13 C 12 "> C13C12 fractionation between carbonate minerals and carbonate ions in aqueous solution was not successful.