Authigenic titanite in weathered basalts: Implications for paleoatmospheric reconstructions

The stability of titanite is sensitive to temperature and partial pressure of CO2. The finding of authigenic titanite grains in weathering regolith formed on Paraná basalts, Brazil, under tropical climatic conditions, reveals the thermodynamically-driven conversion from calcite to titanite at elevated ambient temperatures. Being unusual nowadays, this phase transition provides important implications for the understanding of silicate weathering in earlier geological epochs.