TY - CONF

T1 - A comparison of TT-OSL and post-IR IRSL dating of coastal deposits on Cap Bon peninsula, north-eastern Tunisia

A1 - Thiel,Christine

A1 - Buylaert,Jan-Pieter

A1 - Murray,Andrew S.

A1 - Elmejdoub,Noureddine

A1 - Jedoui,Younes

AU - Thiel,Christine

AU - Buylaert,Jan-Pieter

AU - Murray,Andrew S.

AU - Elmejdoub,Noureddine

AU - Jedoui,Younes

PB - Elsevier BV

PY - 2012

Y1 - 2012

N2 - In this study thermally transferred (TT) OSL and post-IR elevated temperature IRSL (290 °C) (pIRIR290) dating are applied to deposits covering coastal terraces on the Cap Bon peninsula, Tunisia. Both methods perform well under standard performance tests; dose recovery tests using a modern analogue show that doses relevant to our study can be recovered accurately. Residual signals in the modern analogue for both signals are very small (∼2 Gy). For the younger (<250 ka) deposits reasonable good agreement of the ages is observed between both methods, and in addition with standard quartz OSL dating. Systematic discrepancy in ages is found for the older sediments. The TT-OSL underestimate (compared to the pIRIR290 ages) is most likely due to the short lifetime of the TT-OSL trap; we estimate a lifetime of ∼0.7 Ma at 19 °C (mean ambient air temperature of the study area). This is the first time this lifetime has been derived from geological data and it is within the range of previously published laboratory estimates. This result suggests that TT-OSL is not likely to provide a significant extension of the age range beyond that available from other methods. Our preferred pIRIR290 ages suggest that the geological setting on Cap Bon is not as simple as previously suggested.

AB - In this study thermally transferred (TT) OSL and post-IR elevated temperature IRSL (290 °C) (pIRIR290) dating are applied to deposits covering coastal terraces on the Cap Bon peninsula, Tunisia. Both methods perform well under standard performance tests; dose recovery tests using a modern analogue show that doses relevant to our study can be recovered accurately. Residual signals in the modern analogue for both signals are very small (∼2 Gy). For the younger (<250 ka) deposits reasonable good agreement of the ages is observed between both methods, and in addition with standard quartz OSL dating. Systematic discrepancy in ages is found for the older sediments. The TT-OSL underestimate (compared to the pIRIR290 ages) is most likely due to the short lifetime of the TT-OSL trap; we estimate a lifetime of ∼0.7 Ma at 19 °C (mean ambient air temperature of the study area). This is the first time this lifetime has been derived from geological data and it is within the range of previously published laboratory estimates. This result suggests that TT-OSL is not likely to provide a significant extension of the age range beyond that available from other methods. Our preferred pIRIR290 ages suggest that the geological setting on Cap Bon is not as simple as previously suggested.

KW - Post-IR IRSL

KW - TT-OSL

KW - Coastal terraces

KW - Cap Bon peninsula

KW - Tunisia

U2 - 10.1016/j.quageo.2012.03.010

DO - 10.1016/j.quageo.2012.03.010

JO - Quaternary Geochronology

JF - Quaternary Geochronology

SN - 1871-1014

VL - 10

SP - 209

EP - 217

ER -