Uneingeschränkter Zugang

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

Morteza Fattahi
Morteza Fattahi
, 
Mariam Heidary
Mariam Heidary
 und 
Mohammad Ghasemi
Mohammad Ghasemi
   | 20. Mai 2016
Geochronometria's Cover Image
Über diesen Artikel
Vorheriger Artikel
Nächster Artikel
Zitieren
Article Category: Research Article
Online veröffentlicht: 20. Mai 2016
Seitenbereich: 38 - 47
Eingereicht: 11. Juli 2015
Akzeptiert: 02. Feb. 2016
DOI: https://doi.org/10.1515/geochr-2015-0031
Schlüsselwörter
© 2015 M. Fattahi et al
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Regional setting of the EMF and NTF zone showing drainage offsets across the two faults. DAS: Darabad segment of NTF, EMF: Eastern Mosha Fault, FZF: Firuzkuh Fault, GMP: Ghuchak Mountain Pass, NDS: Niknamdeh segment of NTF, NTF: North Tehran Fault zone, SF: Sabu Fault. Squares indicate towns and villages. Breakaway scarp of mass movements are shown by red barbed curves. Note the pull-apart basin in Latyan Basin depression area. Yellowbars showthe two trench sites in this study (not to scale). Arrows and numbers indicate drainage offsets of 9.3, 6.5 and 9.5 km respectively in 1, 2 and 3. Topography is from SRTM data. (Ghasemi et al., 2014).
Regional setting of the EMF and NTF zone showing drainage offsets across the two faults. DAS: Darabad segment of NTF, EMF: Eastern Mosha Fault, FZF: Firuzkuh Fault, GMP: Ghuchak Mountain Pass, NDS: Niknamdeh segment of NTF, NTF: North Tehran Fault zone, SF: Sabu Fault. Squares indicate towns and villages. Breakaway scarp of mass movements are shown by red barbed curves. Note the pull-apart basin in Latyan Basin depression area. Yellowbars showthe two trench sites in this study (not to scale). Arrows and numbers indicate drainage offsets of 9.3, 6.5 and 9.5 km respectively in 1, 2 and 3. Topography is from SRTM data. (Ghasemi et al., 2014).

Part of log of the western trench wall in the Ira site (from Ghasemi et al., 2014).
Part of log of the western trench wall in the Ira site (from Ghasemi et al., 2014).

The De value of IRA samples, representative radial plots of ‘mixed and scattered’ single aliquot De distributions. The grey bands show values of 2 standard deviations from the De CAM estimates (Galbraith et al., 1999) for IRA1 and IRA5. The solid yellow lines show the MAM De, and interpreted as representing almost totally bleached grains, which were used for sample De and age determination. The soild gray lines in IRA4 and IRA8 show FMM De. Over dispersion for IRA1, IRA4, IRA5 and IRA8 are 30, 92, 25 and 57, respectively
The De value of IRA samples, representative radial plots of ‘mixed and scattered’ single aliquot De distributions. The grey bands show values of 2 standard deviations from the De CAM estimates (Galbraith et al., 1999) for IRA1 and IRA5. The solid yellow lines show the MAM De, and interpreted as representing almost totally bleached grains, which were used for sample De and age determination. The soild gray lines in IRA4 and IRA8 show FMM De. Over dispersion for IRA1, IRA4, IRA5 and IRA8 are 30, 92, 25 and 57, respectively

The relative profile likelihood graphs for quartz single aliquots of IRA4 and IRA8 samples.
The relative profile likelihood graphs for quartz single aliquots of IRA4 and IRA8 samples.

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.

SampleWater (%)Depth (m)K (%)U (ppm)Th (ppm)Cosmic (Gy/ka)Dose rate (mGy/yr)
Ira.I5.251.391.071.125.290.16 ± 0.141.77 ± 0.14
Ira.IV9.660.61.331.656.300.18 ± 0.142.14 ± 0.15
Ira.V6.61.221.111.344.990.16 ± 0.141.82 ± 0.14
Ira.VIII8.462.040.771.694.650.14 ± 0.141.52 ± 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.

StepTreatment 1*Ob
1Give dose–
2Pre-heat (TL 200–300°C)–
3Stimulation (at 120°C)LX
4Give test dose–
5Cut-heat (TL 120–260°C)–
6Stimulation (at 125°C)TX
7Return 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).

Sample IDDe (Gy)Age (ka)
CAM±FMM±MAM±CAM±FMM±MAM±
Ira.I11.41.36.40.9
Ira.IV123.911.013.00.97.50.658.06.56.10.63.50.3
Ira.V13.32.07.31.3
Ira.VIII53.37.932.70.920.06.335.06.121.52.213.14.3
eISSN:
1897-1695
Sprache:
Englisch
Zeitrahmen der Veröffentlichung:
Volume Open
Fachgebiete der Zeitschrift:
Geowissenschaften, andere
Zeitschrift RSS Feed