Employing Minimum age model (MAM) and Finite mixture modeling (FMM) for OSL age determination of two important samples from Ira Trench of North Tehran Fault
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Values used to calculate Annual dose rate from IRA trench. Uncertainties are based on the propagation, in quadrature, of errors associated with individual errors for all measured quantities.
Sample
Water (%)
Depth (m)
K (%)
U (ppm)
Th (ppm)
Cosmic (Gy/ka)
Dose rate (mGy/yr)
Ira.I
5.25
1.39
1.07
1.12
5.29
0.16 ± 0.14
1.77 ± 0.14
Ira.IV
9.66
0.6
1.33
1.65
6.30
0.18 ± 0.14
2.14 ± 0.15
Ira.V
6.6
1.22
1.11
1.34
4.99
0.16 ± 0.14
1.82 ± 0.14
Ira.VIII
8.46
2.04
0.77
1.69
4.65
0.14 ± 0.14
1.52 ± 0.14
Generalized single aliquot regenerated sequence and outline of the steps involved in the SAR method. *Observed Lx and Tx are derived from the initial IRSL signal (2 s) minus a background estimated from the last part of the stimulation curve. Corrected natural signal N = L0/T0; Corrected regenerated signal Rx = Lx/Tx (x = 1–5). Note that in step 2, the sample has been heated to the pre-heat temperature using TL and held at that temperature for 10 s.
Step
Treatment 1
*Ob
1
Give dose
–
2
Pre-heat (TL 200–300°C)
–
3
Stimulation (at 120°C)
LX
4
Give test dose
–
5
Cut-heat (TL 120–260°C)
–
6
Stimulation (at 125°C)
TX
7
Return to 1
–
Des used to calculate luminescence ages employing three different statistical methods, Central age model (CAM), Finite mixture modelling (FMM) and Minimum age model (MAM).