TY - JOUR

T1 - Optical dating of perennially frozen deposits associated with preserved ancient plant and animal DNA in north-central Siberia

AU - Arnold, L.J.

AU - Roberts, R.G.

AU - Macphee, R.D.E.

AU - Willerslev, E.

AU - Tikhonov, A.N.

AU - Brock, F.

PY - 2008

Y1 - 2008

N2 - We present chronological constraints on a suite of permanently frozen fluvial deposits which contain ancient DNA (aDNA) from the Taimyr Peninsula of north-central Siberia. The luminescence phenomenology of these samples is first discussed, focusing on the optically stimulated luminescence (OSL) decay curve characteristics, thermoluminescence (TL) properties, and signal compositions of quartz from these previously unstudied deposits. Secondly, we assess the suitability of these samples for OSL dating and present the OSL chronologies obtained using both single-grain and multi-grain equivalent dose (De) measurements. The results of our analyses reveal a large amount of inter-aliquot variability in OSL decay curve shape that is directly related to differences in the size of the 280 degrees C TL peak and the associated slowly bleached 'S2' OSL component. Longer OSL stimulation durations are adopted in the D, measurement procedure to prevent the progressive build-up of slowly bleached signal components throughout successive single-aliquot regenerative-dose (SAR) measurement cycles. The use of low preheat temperatures in the SAR procedure also reduces the deleterious effects of these slowly bleached signal components. The resultant single-grain and multi-grain OSL chronologies obtained using this approach are stratigraphically consistent and are in close agreement with independently established 14 C ages at our sites. The findings of this research reveal the potential of OSL dating as a means of providing a reliable chronometric framework for sedimentary aDNA records in permafrost environments. (C) 2007 Elsevier Ltd. All rights reserved Udgivelsesdato: 2008

AB - We present chronological constraints on a suite of permanently frozen fluvial deposits which contain ancient DNA (aDNA) from the Taimyr Peninsula of north-central Siberia. The luminescence phenomenology of these samples is first discussed, focusing on the optically stimulated luminescence (OSL) decay curve characteristics, thermoluminescence (TL) properties, and signal compositions of quartz from these previously unstudied deposits. Secondly, we assess the suitability of these samples for OSL dating and present the OSL chronologies obtained using both single-grain and multi-grain equivalent dose (De) measurements. The results of our analyses reveal a large amount of inter-aliquot variability in OSL decay curve shape that is directly related to differences in the size of the 280 degrees C TL peak and the associated slowly bleached 'S2' OSL component. Longer OSL stimulation durations are adopted in the D, measurement procedure to prevent the progressive build-up of slowly bleached signal components throughout successive single-aliquot regenerative-dose (SAR) measurement cycles. The use of low preheat temperatures in the SAR procedure also reduces the deleterious effects of these slowly bleached signal components. The resultant single-grain and multi-grain OSL chronologies obtained using this approach are stratigraphically consistent and are in close agreement with independently established 14 C ages at our sites. The findings of this research reveal the potential of OSL dating as a means of providing a reliable chronometric framework for sedimentary aDNA records in permafrost environments. (C) 2007 Elsevier Ltd. All rights reserved Udgivelsesdato: 2008

U2 - 10.1016/j.quageo.2007.09.002

DO - 10.1016/j.quageo.2007.09.002

M3 - Journal article

VL - 3

SP - 114

EP - 136

JO - Quaternary Geochronology

JF - Quaternary Geochronology

SN - 1871-1014

IS - 1-2

ER -