Upper-pressure stability and thermochemical properties of synthetic marialite and its application to calculating paleobrine NaCl concentrations

Marialite (Na3Al3Si9O24·NaCl), the chloride end-member of the scapolite mineral group, is important for determining the chloride content of a paleofluid from which Cl-bearing scapolite formed as well as its potential role in the geochemical cycling of chlorine in tectonically active zones. Experiments on the upper-pressure stability of synthetic marialite breaking down to jadeite + coesite + halite at high pressures were done using a multi-anvil press in the range of 2.6–4.0 GPa and 1050–1250 °C