Extended Data Fig. 8: A comparison of red thermoluminescence and pIR-IRSL luminescence data for sample NDG-1.

a, Quartz red thermoluminescence isothermal decays, showing a natural and regenerative decay. b, The dose response of aliquot A of the DAP technique with a D_e value of 185 ± 53 Gy. The points represent the mean with s.d. uncertainties (too small to see at this scale). c, The dose response of the subtracted aliquot B of the DAP technique with a D_e value of 170 ± 53 Gy. The points represent the mean value with an error as a s.d. of the fit (too small to see at this scale). d, Photographs of the luminescence emitted by a sample from the Ngandong terrace (NDG-1) compared to a sample from the Wae Raceng terrace in Flores (WR-1). The Flores terrace is so bright it has bleached the photographic paper, whereas the Ngandong terrace is much dimmer but the red luminescence emissions are clearly visible. e, Feldspar pIR-IRSL decays for sample NDG-1, showing the natural and regenerative decays. A long stimulation time is required to remove all of the pIR-IRSL signal. f, A dose–response curve for the sample NDG-1 with a D_e value of 150 ± 4 Gy. Each dose point represents the mean value with s.d. uncertainties (too small to see at this scale). g, Fading tests for the sample NDG-1, comparing the fading of the infrared signal at 50 °C (IR₅₀) with the fading with the pIR-IRSL signal at 270 °C (pIR-IRSL₂₇₀)—demonstrating the isolation of a very small fading signal. The points represent the median value with a standard error. h, Radial plot of the NDG-1 single-aliquot data.