Estimation of paleo-firing temperatures using luminescence signals for the volcanic lava baked layer in Datong, China

Abstract

Eight paleo-fired samples from the baked layer in different depths under the lava and one unfired sample were collected from Datong, China. Fine quartz grains (4–11 μm) from samples were used for probing into relationship between luminescence signals and paleo-firing temperatures. Findings from the re-firing experiments indicated that using thermoluminescence (TL) and optically stimulated luminescence (OSL) sensitivity changes could estimate the paleo-firing temperatures of samples: (1) 110 °C TL sensitivity change rate against the re-firing temperature can tell whether the sample has been fired to temperatures above 500 °C or not; (2) 150 °C TL sensitivity against the re-firing temperature can indicate whether the sample has been fired to temperatures above 900 °C or not; (3) the more specific paleo-firing temperatures can be estimated by comparing the ratio of OSL and 150 °C TL sensitivities against re-firing temperatures. Results showed that the paleo-firing temperatures of the eight lava-baked samples decreased exponentially with the distance from the lava. Based on the estimated temperature profile, the temperature of the lava was estimated to be about 1100 °C.