Equilibrium diagrams showing the chemical stability of sphene and the assemblage rutile-quartz-calcite in the range 25-300°C and 1-2000 bar were constructed from mineral reactions that likely occur in diagenetic environments. The results reveal that stability of sphene depends on activities of HCO-3, Ca2+, SiO2(aq) and H+. Given appropriate conditions, sphene is predicted to be stable even in surficial environments.
ASJC Scopus subject areas
- Geochemistry and Petrology