## 3 Results and Discussion
### TL, OSL, and IRSL Results  
TL, OSL, and IRSL equivalent doses (E.D.) were evaluated for all samples; because no mineralogical phase separation was performed on the brick samples, any luminescent mineral contributes to the emission, quartz and feldspars being the main emitters. Both quartz and feldspars have a TL emission in the blue region of the spectrum, and their contribution is not separate. For what concerns OSL, while blue light stimulates the emission of both quartz and feldspars, IR light only stimulates feldspars; for this very reason, both OSL and IRSL were performed. Typical examples of TL glow curves are shown in Figure 8a. Based on the plateau test, which allows us to identify the thermally stable portion of the curves ([PERSON], 1985), the TL signals were integrated between 300 and 350 \({}^{\circ}\)C. Plotting the intensity of the TL signal vs. the laboratory-imparted dose, E.D. was extrapolated by linear regression, as illustrated in Figure 8b. The results of such evaluations are summarized in Table 3.  
Typical OSL/IRSL shine-down curves are shown in Figure 8c-e. The samples were stimulated for 40 s in case of OSL measurement and 100 s for IRSL. The preheat temperature was 200 \({}^{\circ}\)C for 10 s while the cut-heat was 180 \({}^{\circ}\)C, and it was chosen using a preheat plateau test. For the E.D. determination, the initial part of the OSL/IRSL decay curve was used, specifically the first 0.6 s for OSL and the first 1.6 s for IRSL. The background was assumed as the average signal of the last 10 s (OSL) or 20 s (IRSL) of stimulation. Plotting the intensity of the OSL/IRSL signal vs. the laboratory-imparted dose, E.D. was determined through the interpolation of the natural signal on the linear regression, as illustrated in Figure 8d,f. In general, it can be said that the luminescence signals of the samples are rather weak, especially as regards the OSL signal. For this reason, it was possible to use this technique only to date the Padum Pukhuri sample, whose OSL curves have a sufficiently high intensity. IRSL, on the other hand, is the technique that gave the most intense signals for all samples. By looking at the dating results obtained with TL, OSL, and IRSL (Table 3), it is possible to observe that the low luminescence intensity of the samples caused high errors in the ages obtained. The results obtained with TL are in good agreement with those obtained with IRSL, except for the Padum Pukhuri sample. For the latter sample there is instead a good agreement between the ages obtained with TL and OSL. It is well-known that minerals like feldspars can provide underestimated ages for the presence of anomalous fading [83], a malign phenomenon due to the loss of charge from thermally stable defect sites via non-thermal mechanisms. A specific fading test was, therefore, performed at room temperature for one month, and a significant loss of signal was observed, as shown in Figure 9 for the Padum Pukhuri sample. Therefore, fading evaluations were performed on all samples for all the luminescence techniques used (TL, IRSL, and OSL). For each sample and for each type of luminescence, the g-values [84] were determined (see Table 4). The ages of the samples obtained were then recalculated according to the equation reported in [84] to obtain the dates corrected for the fading phenomenon (Table 4). Figure 8: (**a**) TL glow curves, (**c**) OSL, and (**e**) IRSL shine-down curves of the Padum Pukhuri sample. (**b**) Growth curve of the TL signal with imparted additive dose. TL glow curves were integrated between 300 and 3500 \({}^{\circ}\)C, and the signal of the background in the same temperature interval (green line) was subtracted. Sensitivity-corrected (**d**) OSL and (**f**) IRSL response to a fixed dose vs. the laboratory-imparted regenerative dose. The red dot is the natural signal, and the blue triangle is the recycling ratio point. The high g-values (>7%) obtained for nearly all the samples suggest the presence of some luminescent mineralogical phase other than feldspars with a high fading rate.