Quaternary Science Reviews 20 (2001) 719}724
The potential of OSL and TL for dating Lateglacial and Holocene
dune sands tested with independent age control of the Laacher
See tephra (12 880 a) at the Section &Mainz-Gonsenheim'夽
U. Radtke *, A. Janotta , A. Hilgers , A.S. Murray
Department of Geography, University of Cologne, Albertus-Magnus-Platz, D-50923 Cologne, Germany
Nordic Laboratory for Luminescence Dating, Department of Earth Sciences, Aarhus University, Ris~ National Laboratory, DK-4000 Roskilde, Denmark
Abstract
Optically stimulated luminescence (OSL) and Thermoluminescence (TL) are applied in this study to date a Lateglacial and
Holocene aeolian sediment sequence. Quartz and potassium rich feldspars extracted from dune sands from western Germany were
dated using both multiple-aliquot (MA) and single-aliquot (SA) protocols for luminescence dating. This particular dune section was
chosen for this test study, because an independent age control is provided by a horizon of the Laacher Seetephra (12,880 a).
In contrast to the results for potassium feldspars, which show underestimation of up to 25%, the quartz fraction provides promising
results with respect to the presumed geological ages. 2000 Elsevier Science Ltd. All rights reserved.
1. Introduction
We present the results of a systematic investigation of
12 samples of the dune section &Mainz}Gonsenheim' near
the river Rhine close to Mainz (about 50300'25''N,
8311'10''E) in Rhineland}Palatinate, Germany. This
study is part of a long-term research project which deals
with the di!erent phases of dune accumulation in Central
Europe during the Lateglacial and Holocene. One of the
main problems is to determine whether the sand was
deposited within a small number of short periods of high
aeolian activity or if dunes and cover sands result from
a more or less continuous accumulation.
The dune at Gonsenheim was chosen to test the potential of luminescence dating for Lateglacial and Holocene
dune sands because an independent age control is provided by a layer of Laacher See tephra. This stratigraphic
marker horizon was dated with varve chronology at
12 880 a (Brauer et al., 1997).
2. Description of the site
The dune section &Mainz}Gonsenheim' is located
about 2 km south of the river Rhine in an extensive
夽
Paper published in December 2000.
* Corresponding author. Fax: 0049-221-4705124.
E-mail address: [email protected] (U. Radtke).
aeolian sand sheet. The river terrace deposits of the
Pleistocene braided river system yielded the material for
widespread de#ation processes during the Late Weichselian and Postglacial time. The main accumulating
winds are assumed to be from the north west.
In Fig. 1 a model is shown which summarises the
di!erent phases of dune accumulation at the location
&Mainz-Gonsenheim' following the interpretation of
StoK hr (1966) and Hanke and Maqsud (1985). A description of the sediments exposed at the section &MainzGonsenheim' and the sampling positions are presented in
Fig. 2.
The accumulation of the dune started during the late
Pleniglacial and Oldest Dryas period, when a low water
level of the river Rhine together with a sparse vegetation
cover as a result of cold and dry climate conditions
caused the exposure of extensive de#ation areas. A charcoal C age of 15.2$0.4 ka (uncal.) BP (Hanke and
Maqsud, 1985) from the bottom of Section 9 (Fig. 2)
supports this interpretation. An indication on strong
aeolian processes with high accumulation rates is the
homogeneity of the sediment (Section 9 in Fig. 2). The
two weakly developed palaeosols, which are separated by
a layer of unweathered windblown sand (Section 7 in Fig.
2, sample MG8), are correlated with the B+lling- and
Aller+d-interstadial period, respectively (Sections 8 and
6 in Fig. 2). The chronostratigraphic marker of this
section, &25 cm thick layer of the Laacher See tephra
(Section 5 in Fig. 2, sample MG7), was deposited directly
0277-3791/01/$ - see front matter 2000 Elsevier Science Ltd. All rights reserved.
PII: S 0 2 7 7 - 3 7 9 1 ( 0 0 ) 0 0 0 2 7 - 5
720
U. Radtke et al. / Quaternary Science Reviews 20 (2001) 719}724
eral later phases of remobilization of dune sands after the
Subboreal (see Fig. 1 phase VI and VII). These sediments
are not exposed at our sampling section, but are
documented as widespread in the local area (Hanke and
Maqsud, 1985).
3. Measurement facilities and equivalent dose (D )
determination
Fig. 1. Model of the dune development and the di!erent phases of
sediment accumulation at the section &Mainz-Gonsenheim' (modi"ed
from StoK hr, 1966; Hanke and Maqsud, 1985).
Phase I and II: Last Glacial Maximum-Oldest Dryas (1) B+lling, (2)
Older Dryas (3) Aller+d, (4) Plase III: Laacher See Tephra, (5) Reworked sediments (Younger Dryas) (6) De#ation, accumulation and
cryoturbations (Younger Dryas), (7) Phase IV and V: Preboreal } initial
soild development (8) Atlanticum } development of Luvisol (9) Phase
VI and VII: Subboreal } mobilisation and accumulation of wind-borne
sands, (10) Subatlanticum } di!erent phases of mobilisation (de#ation,
accumulation, younger dunes, Ap-horizon, development of Luvisol,
initial Regosol) (11).
on the presumably Aller+d-palaeosol. The unusual thickness of the layer is explained by the location of the section
on the leeward side of the dune: strong winds short after
the deposition caused the de#ation of the tephra on the
windward position and the accumulation in the lee.
The subsequent covering with reworked sediments during the Younger Dryas period prevented later de#ation
of the tephra. Strong aeolian as well as cryogenic processes are typical of the stadial climate conditions of the
Younger Dryas. The period of high aeolian activity lasted
until the beginning of the Preboreal (Sections 4 and 3 in
Fig. 2, samples MG6-3). During the Atlanticum a luvisol
developed from these sediments (Section 2 in Fig. 2,
samples MG 2-1). With the increased population in the
study area, human impact on the landscape caused sev-
All samples were prepared in subdued red light
('600 nm). The grain size fraction of 100}200 lm was
extracted by dry sieving. Samples were then treated with
hydrochloric acid, sodium oxalate and hydrogen peroxide in order to remove carbonates, clay and organic
material. For mineral separation solutions of sodium
polytungstate (2.58, 2.62 and 2.7 g cm\) were used to
concentrate the quartz fraction and separate the potassium rich feldspars ((2.58 g cm\).
To avoid contamination with feldspars the quartz
samples (MG6, 7 and 8) were etched in 40% hydro#uoric
acid for 40 min, followed by a treatment with hydrochloric acid to remove acid-soluble #uorides and re-sieving of
the residual-quartz grains. All samples were "xed with
silicone oil spray on 10 mm diameter discs, of stainlesssteel in the case of SA and of aluminium in the case of
MA measurements.
Several luminescence methods were applied: IRSL and
TL (regeneration and additive dose method) on K-feldspars and GLSL and TL (regeneration dose method) on
quartz. A detailed description of these datasets is given in
Radtke and Janotta (1998). Here we report in particular
on further investigations on the three samples, MG 6,
7 and 8, taken from above, within and below the Laacher
See tephra horizon (see Fig. 2). In addition to the other
procedures, single-aliquot measurements were employed
using the single-aliquot regenerative-dose protocol
(SAR) for quartz, as most recently described by Murray
and Wintle (2000).
All luminescence measurements were performed using
automated Ris+ readers (type TL-DA-12). The multiplealiquot measurements were carried out at the laboratory
in Cologne and the single-aliquot measurements at the
Ris+ National Laboratory in Roskilde. Important details
and di!erences between the protocols employed in this
study are summarised in Table 1. The equivalent doses
were calculated using the integrals as noted in Table 1.
For all OSL measurements of quartz the luminescence
detected in the last 10 s of stimulation was subtracted as
background signal (Murray and Wintle, 2000). To calculate the D based on the SAR measurements the preheat
plateau from 1603 to 3003C ("rst dataset, n"24 aliquots)
and 180}2803C (second dataset, n"19), respectively, was
used (Murray and Wintle, 2000). The gamma-doses used
for irradiation of the subsamples (n"35) for the MA
measurements were: 4.45, 8.9, 17.8, 35.6, 71.2, 124.6, 178
Fig. 2. The dune section &Mainz-Gonsenheim': description of the horizons, sample positions and results of the luminescence dating. (} D not determinable, n.m. not measured).
U. Radtke et al. / Quaternary Science Reviews 20 (2001) 719}724
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U. Radtke et al. / Quaternary Science Reviews 20 (2001) 719}724
Table 1
Measurement parameters for the di!erent protocols
Multiple-aliquot protocols
Quartz (HF etched)
K-rich feldpars
Quartz
Single-aliquot protocol
IRSL-MAR
TL-MAR
IRSL-MAA
TL-MAA
GLSL-MAR-1 TL-MAR
GLSL-MAR-2 BLSL-SAR
Several hours
with sunlight
Co!csource
HA3-BG39
Several hours
with sunlight
Co!csource
HA3-BG39
*
*
Co!csource
HA3-BG39
Several hours
with sunlight
Co!csource
HA3-U340
Several hours
with sunlight
Co!csource
HA3-2;U340
100 s with blue
diodes
Sr/Y!bsource
HA3-3;U340
Preheating
*
2303C/60 s
Co!csource
HA3-BG392;BG3GG400
*
Several hours
with sunlight
Co!csource
HA3-U340
2303C/60 s
2203C/300 s
*
2203C/300 s
Stimulation
IR-diodes
Heating up to IR-diodes
(880$80 nm) 4503C with
(880$80 nm)
53C/s
503C
*
503C
2}50 s
280}420 s
2}50 s
Plateau: 10 s
160}3003C,
180}2803C
Blue diodes
(470$30 nm)
Bleaching
Irradiation
Filterset for
detection
Aliquot temp.
Integral used for
D calculation
Heating up to Blue/green
4503C with
broad-band
53C/s
(420}550 nm)
*
503C
280}420 s
2}50 s
Heating up to Blue/green
4503C with
broad-band
53C/s
(420}550 nm)
*
1253C
280}420 s
0}0.4 s
1253C
0}0.4 s
Note: MAR * multiple-aliquot regenerative-dose protocol, MAA * multiple-aliquot additive-dose protocol
Gy. Nine or 13 discs were used to measure the natural
luminescence signal for the MA protocols.
In Fig. 3 all D values obtained for the samples MG 6,
7, and 8 are compared. The di!erences in the measurement equipment make the comparison di$cult (see Table
1, e.g. di!erent stimulation sources used for MA and SA
quartz measurements), but nevertheless the discrepancies
are clear. Two facts have to be emphasised: "rst, the
distinct di!erence between the D value determined by
using the SA protocol and all values obtained by applying the MA protocols, which is not dependent on the
mineral fraction used; and secondly the broader error
bars of all MA equivalent dose values compared with the
SA value. The signi"cant deviation between the MA and
the SA equivalent doses of quartz could be possibly due
to sensitivity changes, which are measured and corrected
for with the SAR protocol, but not with the MAR protocol. The sensitivity changes observed between the SAR
natural and the "rst regeneration cycle were by a factor
of 1.11 (MG6), 1.10 (MG7), and 1.12 (MG8). This increase
in sensitivity must have been present in the MAR data
sets as well, but was not measured and not corrected for
in the MAR measurement routine.
The feldspar MA D results should be &30% greater
than the quartz data resulting from the higher internal
dose rate of K-feldspars; this is not observed here. Comparing the equivalent doses of the MAR protocols for
feldspar (IRSL preheated) and etched quartz (GLSL-2)
the feldspar D values for samples MG6-8 are only 8, 3,
and 15% higher than those obtained for the quartz
fraction (see Fig. 3). This should result in a greater age
underestimation of the potassium feldspars compared to
the quartz fraction than the calculated ages really show
(for samples MG6}8 underestimation &11%). One
explanation could be the problems with the determination of the internal K content of the K-feldspars by
Fig. 3. Comparison of the equivalent doses of the samples MG6, 7, and 8 obtained with di!erent protocols for quartz (Q) and potassium rich
feldspars (F).
U. Radtke et al. / Quaternary Science Reviews 20 (2001) 719}724
723
Table 2
Dose rates (D ), equivalent doses (D ) and calculated luminescence ages for the samples MG6, 7 and 8
Sample
D in Gy/ka
D in Gy
Age in ka
NAA (U, Th),
X-ray #uores. (K)
c-Spec.
Quartz GLSL-MAR-2
Quartz BLSL-SAR
Quartz - GLSL-MAR-2
and NAA/X-ray-#uores.
Quartz - BLSL-SAR
and c-Spec.
MG6
1.99$0.07
2.58$0.08
26.1$4.2
13.10$2.89
MG7
3.09$0.10
3.81$0.11
30.7$4.9
MG8
2.28$0.13
2.44$0.08
27.8$5.0
36.6$1.4
34.6$1.1
44.4$1.0
45.4$1.0
37.1$0.9
35.6$1.2
14.16$1.37
13.39$1.24
11.65$0.98
11.91$0.99
15.22$1.45
14.60$1.47
9.94$2.17
12.19$3.12
Second dataset: preheat plateau 180}2803C.
b-counting. Whereas for MG8 with 11.7% a typical value
for potassium feldspars was obtained (Huntley and Baril,
1997), for samples MG6 and 7 with &7.4% very low
contents were measured. This problem is presumably
sample speci"c.
The better precision of the quartz D values obtained
with the GLSL-MAR-2 protocol than of the MAR-1
equivalent doses (see Fig. 3) is probably due to the
normalisation procedure (0.1 s optical stimulation prior
to bleaching and irradiation), which was carried out in
the case of MAR-2 but not for MAR-1. Whereas a higher
precision of SA measurements in contrast to MA
measurements is one advantage of the SA protocols (see,
for example, Banerjee et al., 2000), we can give no "nal
explanation for the di!erence in the values of the MA and
SA protocols.
4. Dose rate (D0 ) estimation
The results of the dose rate calculation for all 12
samples, using Neutron-Activation-Analysis (NAA), Xray #uorescence for the determination of the radionuclide contents of the sediment, and beta-counting for
measuring the internal K-content of the potassium rich
feldspars, are described in detail in Radtke and Janotta
(1998).
For age calculation based on the results of the MA
measurements the uranium and thorium contents as
determined by NAA and the potassium contents as
measured with X-ray-#uorescence were used (see
Fig. 2 for luminescence ages obtained by applying the
regeneration method).
High resolution gamma-spectrometry was carried out
at the Ris+ laboratory on samples MG6, 7, and 8. In
Table 2 we compare the annual dose rates resulting from
gamma-spectrometry with those based on NAA (for
U and Th) together with X-ray-#uorescence (for K). The
di!erence in the calculated dose rates is obvious. Radioactive disequilibrium did not cause this di!erence in the
dose rates as could be seen from the results of the
gamma-spectrometry. The deviation is possibly due to
the di!erence in sample sizes used for analysis (more than
200 g for gamma-spectrometry and only several mg for
NAA). For the samples MG6 and 7, in particular, an
inhomogeneous distribution of volcanic material in the
samples could give rise to the variances in dose rates,
which are signi"cantly larger than for sample MG8
(taken from unweathered dune sand, see Fig. 2). The
ratios of gamma-spectrometry dose rates to NAA/XRF
dose rates are 1.30$0.09 (MG6), 1.24$0.08 (MG7) and
1.08$0.10 (MG8) showing the best, but still not good,
agreement for sample MG8.
5. Discussion and conclusion
We applied several protocols with the aim of testing
their potential for dating sediments deposited during the
Lateglacial and Holocene. Because of the broad spread of
the data and partly because of the broad error bars (see
Fig. 3 for samples MG6, 7 and 8) the results of the
luminescence measurements are not satisfactory, although the high precision of the equivalent doses obtained with the SAR protocol is encouraging when
compared with the results of the multiple-aliquot protocols (see Fig. 3).
The comparison of the dose rates based on NAA and
gamma-spectrometry, respectively (see Table 2), is also
unsatisfactory and further investigations will be undertaken to "nd out the reason for the di!erence of the
results.
All results of luminescence dating, regardless of the
method and protocol used (see. Fig. 2), prove the Lateglacial and early Holocene age of the dune, as expected
from the relative chronology (see Fig. 1). As described in
detail in Radtke and Janotta (1998) the ages of the potassium feldspar fraction tend to show age underestimations
when compared with the quartz ages and the independent age control provided by the Laacher See tephra and
the C age of about 15 ka uncal. BP for the bottom part
of the dune (see Fig. 2).
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U. Radtke et al. / Quaternary Science Reviews 20 (2001) 719}724
Although there are still problems, we conclude that
there is, in general, a high potential for dating Holocene
and Late Pleistocene dune sands with luminescence dating. But at this point we cannot decide de"nitively which
luminescence dating protocol is the most suitable. Considering the results with respect to the age control provided by the Laacher See tephra, we would give
preference to the ages calculated from the results of the
SAR measurements of quartz combined with the dose
rate determination based on gamma-spectrometry. These
ages show both: the highest precision and the best accuracy of the samples dated in this study; in particular the
sample from within the tephra layer (MG7, 11.9$1.0 ka)
is in good agreement with the independent age of 12.9 ka.
Nevertheless, it is not acceptable that for the same
samples, di!erent dose rates and equivalent doses could
be obtained which result in similar ages. The sample
preparation was all carried out in one laboratory, therefore we can exclude that the preparation procedures and
laboratory conditions caused the di!erences. Further factors are to be investigated, e.g. the in#uence of di!erent
wavelengths used for bleaching in the application of the
regeneration method (full sunlight spectrum for MA protocols and blue diodes for SA measurements).
Acknowledgements
This study was "nancially supported by the Deutsche
Forschungsgemeinschaft (DFG, grant Ra 383/3).
Our thanks to Prof. Dr. G. Schmitt and Dipl.-Phys.
B. Bannach for making possible the irradiation with
the Co-source at the Department of Nuclear Medicine
of the University of DuK sseldorf, Germany. Prof. Dr. em.
A. Semmel is thanked for enabling the sampling at
Mainz-Gonsenheim and helpful comments on the "eldwork. The visit of A. H. to the Ris+ Laboratory was
funded by the &KaK the-Hack'-foundation (University of
Cologne).
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