Calibration of carbonaceous material Raman geothermometry and zircon (U-Th)/He thermochronometry for diagenetic to very low-grade metamorphic conditions
In the temperature range of deep mesodiagenetic to very low-grade metamorphic conditions (i.e. ~150 to ~300 °C) the classical organic geothermometers provide only semi-quantitative temperature information. Raman spectroscopy of carbonaceous material (RSCM) is an established geothermometer, which is mainly used to determine metamorphic temperatures. The goal of this project is performing a precise calibration of the RSCM thermometer for this low temperature range by both natural case studies and thermal maturation experiments in the laboratory. The laboratory experiments primarily aim to describe the impact of the type of organic precursor material on RSCM data and to study the transformation kinetics of carbonaceous material. Cross-calibration of the RSCM geothermometer to the zircon (U-Th)/He geochronometer aims to cover the time-temperature field between shallow diagenetic and metamorphic conditions. The combination of these methods is expected to deliver essential data for reconstructing the thermal evolution of the deep parts of sedimentary basins, as well as for regional tectonic models.