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1.
Vagn Mejdahl 《Norwegian Archaeological Review》2013,46(1-2):21-29
Over the last few years the Nordic Laboratory for Thermoluminescence (TL) Dating has obtained TL dates for a considerable number of archaeological samples, ceramics, bricks, burnt clay and burnt stones from the Nordic countries. The majority of TL dates have been consistent and in agreement with other dating evidence. Discrepancies caused primarily by excessive short‐term fading of the latent TL signal were encountered in a few cases. A procedure for eliminating errors caused by short‐term fading is described. A brief discussion of the sources of error in TL dating is given. Finally, results obtained by TL are compared with those obtained by radiocarbon for a number of sites. 相似文献
2.
Among the dating methods in archaeology, thermoluminescence (TL) is widely developed. The present research concerns the construction chronology of the citadel of Termez (Uzbekistan) in the medieval period. On the methodological side along the TL study, we had to take into account two decisive factors that are expected to affect the accuracy: control of anomalous fading on the polymineral fraction (quartz and feldspars) and the effect of thermal treatments on the luminescence properties of the dated material. With regard to the determination of the annual dose, difficulties, associated with the evolution of the radiochemical composition of the dated samples and their environment over time, were overcome. 相似文献
3.
Review and assessment of the potential of post-IR IRSL dating methods to circumvent the problem of anomalous fading in feldspar luminescence 总被引:2,自引:0,他引:2
Quartz has been the main mineral used for optically stimulated luminescence (OSL) dating of sediments over the last decade. The quartz OSL signal, however, has been shown to saturate at relatively low doses of ~200–400 Gy, making it difficult to be used for dating beyond about 200 thou-sand years (ka), unless the environmental dose rate is low. The infrared stimulated luminescence (IRSL) from feldspars has been shown to continue to grow to higher dose levels than quartz OSL. The application of IRSL dating of feldspars, however, has long been hampered by the anomalous fading effect. Recent progress in understanding anomalous fading of the infrared stimulated luminescence (IRSL) signals in potassium-feldspar has led to the development of post-IR IRSL (pIRIR) protocols and also a multiple elevated temperature (MET) stimulation (MET-pIRIR) protocol. These procedures have raised the prospect of isolating a non-fading IRSL component for dating Quaternary deposits containing feldspars. In this study, we review the recent progress made on (1) overcoming anomalous fading of feldspar, and (2) the development of pIRIR dating techniques for feldspar. The potential and problems associated with these methods are discussed. 相似文献
4.
Recent work has identified IR stimulated luminescence signals at elevated temperature from both potassium- and sodium-rich
feldspars that have much lower anomalous fading rates than the conventional signal measured using IR stimulation at 50°C.
This paper examines the stability of these signals for potassium-rich sedimentary feldspars. We show that the natural post-IR
IRSL (pIRIR) signal from a 3.6 Ma old sample is in apparent saturation on a laboratory generated dose response curve, i.e.
it does not show detectable fading in nature although a low fading rate is observed on laboratory time scales. We show that
the pIRIR signal has a greater thermal stability than the IRSL signal and that the trend in increasing thermal stability is
mirrored by a decreasing fading rate. We also investigate the effect of preheat temperature and IR stimulation power on the
decay shape and conclude that the data can be explained in terms of either a single- or multiple-trap model. We present evidence
that may suggest that at least part of pIRIR signal is derived from a high temperature trap (∼550°C thermoluminescence (TL)
peak), although again the data can also be explained in terms of a single-trap model. Finally, we present dose response curves
and characteristic curvature constants (D0) values for various IRSL signals and conclude that the more stable signals saturate more quickly than the less stable signals
and that the initial and final signals saturate at approximately the same level. 相似文献
5.
A new thermoluminescence (TL) technique for determining the age of heated flint artefacts from archaeological sites is presented. It is a variant of the SAR protocol, which is usually used for OSL dating of sediment, but it is not based on a presumed model for fitting the dose–response curve. Dose recovery tests as well as comparisons with standard protocols show the accuracy of the new technique. It is found that the sensitivity of the thermoluminescence (TL) signal of flint in the orange–red waveband does not show severe changes due to the heating process while measuring the TL. This allows the application of a short SAR procedure, which requires only two dose points. The technique does not require as much instrument time as other SAR techniques, and thus is advantageous for dating very old samples. The major advantage of this new technique is the small amount of sample material required, which allows the dating of samples that are too small for standard TL dating techniques. 相似文献
6.
Christine Thiel Jan-Pieter Buylaert Andrew S. Murray Sumiko Tsukamoto 《Geochronometria》2011,38(4):369-378
Recent work on infrared stimulated luminescence (IRSL) dating has focussed on finding and testing signals which show less
or negligible fading. IRSL signals measured at elevated temperature following IR stimulation at 50°C (post-IR IRSL) have been
shown to be much more stable than the low temperature IRSL signal and seem to have considerable potential for dating. For
Early Pleistocene samples of both European and Chinese loess natural post-IR IRSL signals lying in the saturation region of
the laboratory dose response curve have been observed; this suggests that there is no significant fading in nature. As a contribution
to the further testing of post-IR IRSL dating, we have used 18 samples from two Japanese loess profiles for which quartz OSL
and tephra ages up to 600 ka provide age control. After a preheat of 320°C (60 s), the polymineral fine grains (4–11 μm) were
bleached with IR at 50°C (200 s) and the IRSL was subsequently measured at 290°C for 200 s. In general, the fading uncorrected
post-IR IRSL ages agree with both the quartz OSL and the tephra ages. We conclude that the post-IR IRSL signal from these
samples does not fade significantly and allows precise and accurate age determinations on these sediments. 相似文献
7.
Plagioclase feldspar is the major luminescent mineral in meteorites. Thermoluminescence (TL) characteristics, peak temperature (Tm), full width at half maximum (FWHM), ratio of high (HT) to low temperature (LT) peak, and TL sensitivity (TL/dose/mass) to an extent reflect degree of crystallinity of the mineral. The present study explores and establishes a correlation between quantum mechanical anomalous (athermal) fading and structural state by examining TL of individual chondrules. Chondrules were separated using freeze-thaw technique from a single fragment of Dhajala meteorite. The results show large variation in Tm (155?230°C), FWHM (80?210°C) and HT/LT (0.07–0.47) and seem to be positively correlated. TL sensitivity (ranging from 14 to 554 counts/s/Gy/mg) decreases with increasing Tm and FWHM. Large variations in TL parameters (Tm, FWHM, HT/LT, and Sensitivty) suggest that individual chondrules had different degree of crystallization. Thermal annealing experiments suggest that comparatively ordered form of feldspar can be converted to a disordered form by annealing the sample at high temperatures (1000°C) for long time (10 hr) in vacuum (1 mbar pressure) condition and rapidly cooling it. Measured anomalous fading suggest that fading rate increases as the crystal form changes from an ordered state to a disordered state. However, the fading rate becomes nearly negligible for the most disordered feldspars. 相似文献
8.
Maria Łanczont Andrij B. Bogucki Stanisław Fedorowicz Jarosław Kusiak 《Geochronometria》2011,38(4):350-358
The history of the interlaboratory comparison of TL dating results in Poland started in the 1980s. At that time the Lublin,
Warsaw and Silesian laboratories made the first attempts at TL dating of the same loess samples from the Odonów profile. However,
the cooperation ceased for many years due to great differences in the obtained TL age estimates. The next interlaboratory
comparisons were made in the years 2000–2009 for the loess samples from several Polish (Dybawka, Tarnawce, Dankowice, Biały
Kościół) and Ukrainian (Boyanychi, Halych, Velykyj Hlybochok, Yezupil) profiles. Most of the compared dates, obtained for
the loess deposits from the Upper Pleistocene and younger part of the Middle Pleistocene, were consistent. This encouraged
us to undertake the Gdańsk-Lublin interlaboratory cooperation in dating of 200-700 ka old loess deposits. Nine samples were
taken from the Ukrainian profile Mamalyha 2 in 2009 for this purpose. The TL dating results indicate that comparable dates
are obtained in two laboratories for loess deposits younger than 300 ka BP. The TL signal obtained in the Gdańsk laboratory
for the samples older than 300 ka BP was saturated so such samples should not be dated by the multi-aliquot regeneration method.
The results obtained in the Lublin laboratory for these deposits (489–682 ka) confirm that it is possible to date loess deposits
older than 500 ka. It probably results from the use of total-bleach method with preheating at 160°C for the equivalent dose
determination. 相似文献
9.
P. Morthekai Mayank Jain Pedro P. Cunha José M. Azevedo Ashok K. Singhvi 《Geochronometria》2011,38(3):223-230
The use of feldspar for luminescence dating has been restricted because of anomalous fading. This has made its application
to several important geological problems such as volcanic terrains difficult. Presently, two correction procedures are used
to correct for anomalous fading. The present study tests these correction procedures using volcanic samples of known ages
spanning the time period of 400 ka to 2.2 Ma. These correction procedures provided grossly underestimated ages (up to 60%).
The possible causes for the underestimation are discussed. 相似文献
10.
为了考察对一件已经经过X荧光分析实验的陶瓷样品进行热释光年代测定时,年代结果是否会受到X荧光分析实验的影响及其影响程度,本工作选取了古代与现代的陶器、瓷器及三彩样品共26件,在常规、经过胎体成分分析、经过釉层成分分析三种实验条件下测量比较热释光年代的变化.研究发现,对不同时代不同类型的样品,X荧光成分分析实验对热释光测年的影响程度不同;对部分样品的测年结果无影响,对部分样品的年代有增大的影响,但增大的程度不会使热释光测年结果产生真假颠倒的结论. 相似文献
11.
Luke A. Gliganic Zenobia Jacobs Richard G. Roberts 《Archaeological and Anthropological Sciences》2012,4(2):115-135
Mumba rockshelter is a key archaeological site for the Middle and Later Stone Age occupation of East Africa, but its chronology
has remained unresolved. We report the results of a dating study, focussing on the characterisation of the optically stimulated
luminescence (OSL) and infrared stimulated luminescence (IRSL) properties of quartz- and potassium-rich feldspar grains. Quartz
has previously proven troublesome for dating in East Africa. We identified five general types of quartz grain behaviour, based
on the shapes of their OSL decay and dose–response curves. Dose recovery experiments and measurement of the natural samples
revealed particular problems with quartz grains that had hyperbolic dose–response curves, low characteristic saturation doses
and anomalously large changes in sensitivity between regenerative-dose cycles. The use of pulsed irradiation during measurement
and standard and additional quality-assurance criteria during data analysis reduced the number of grains that suffered from
these problems. We applied these procedures to individual grains of quartz from eight samples and, using appropriate statistical
models, identified post-depositional mixing in three samples. The remaining samples had scattered equivalent-dose distributions
typical of quartz grains that had received variable beta dose rates during burial. Stratigraphically consistent OSL ages were
obtained for all but the deepest sample. Feldspar ages were estimated for the latter sample and three other samples, using
the elevated temperature IRSL signal that exhibited low rates of anomalous fading. Fading-corrected feldspar ages for the
latter three samples are consistent with their single-grain quartz ages, but single-grain dating is needed to address problems
of post-depositional mixing. 相似文献
12.
The aim of this study is to achieve a better understanding of some of the factors that limit the thermoluminescence (TL) dating of glass. Using a‘model system’(lithium-disilicate samples having different levels of crystallinity from 0 to 100%), we show, first, that the TL of glass is reproducible only if the glass is not heated above its temperature glass transition and second, that there is a clear connection between the TL sensitivity and the degree of crvstallinity of the sample. We conclude that thermoluminescence is not a general dating method for archaeological glass, but it can be applied to particular glass samples that haue specified characteristics. 相似文献
13.
R. H. TEMPLER 《Archaeometry》1993,35(1):117-136
Fired ceramics containing zircon inclusions have been dated by allowing the zircons to regenerate their own thermoluminescence (TL) signal, hence auto-regenerative TL dating. The technique is conceptually straightforward. One first measures the TL accrued since the last heating of the material. The zircon grains are then stored for six months and the TL signal regenerated through self-irradiation is measured. Since the internal dose-rate for zircon is dominated by the internal component the age of the sample is simply given by the ratio of the natural to auto-regenerated signal times the laboratory storage period. The technique, however, requires the measurement of a very small auto-regenerated signal, which introduces a number of experimental and physical complications. The methods for overcoming these problems and successfully dating zircons by auto-regeneration are described. 相似文献
14.
The thermoluminescence (TL) dating method has a significant measurement error margin reaching almost 10%. Due to this fact
it could be considered as little effective in case of such sites from the Roman period as burial grounds with many artefacts
useful for archaeological dating. However, for many settlements from this period, where pottery is the only kind of artefacts,
the TL method can give notable results. The main purpose of the study was to make an attempt at TL dating of pottery and clay
daub samples from the Nieszawa Kolonia and Kręcieszki sites and to compare the obtained dates with the results of archaeological
dating of selected features from the Przeworsk Culture settlements. In the Kręcieszki site the fragments of burnt clay daub
were dated by the TL method for the first time in the Lublin laboratory. It turned out that clay daub is an equally good dating
material as pottery. It can be found that the TL dating of pottery from Nieszawa Kolonia confirms two stages of settlement.
The first settlement stage is related to the phases B2-B2/C1-C1a of the Roman period, i.e. from the beginning of the 2nd to the beginning of the 3rd century. The second group of TL dates corresponds to the phases C2D that is to the second stage of settlement, from the second
half of the 3rd century to the half of the 5th century AD. The results of TL dating of pottery and clay daub in the Kręcieszki site are rather similar and correspond to
the phase B1/B2 of the period of Roman influence, determined from pottery style, but can also indicate the phase B2/C1. 相似文献
15.
Alicja Chruścińska Anna Cicha Natalia Kijek Piotr Palczewski Krzysztof R. Przegiętka Krystyna Sulkowska-Tuszyńska 《Geochronometria》2014,41(4):352-360
Saint James Church in Toruń is one of the most important gothic monuments in Poland. The date of the beginning of its construction is known from historical reports but the earlier history of the site remains undiscovered. During the archaeological excavations in years 2010 and 2011 five brick samples were collected for luminescence dating as well as four additional samples from the brick surroundings for the dose rate estimation. The equivalent dose was determined by TL and OSL methods. The TL results differ significantly from the OSL results but the last ones are verified by historical knowledge and radiocarbon dating. Establishing the dose rate from gamma rays needs a special attention because of the complex course of the foundations of the church. The details of the applied approach are presented in the current work. The results obtained indicate that a solid brick construction existed at the site of the presbytery of the Saint James Church before it was build. 相似文献
16.
Luminescence dating has been applied to volcanogenic outburst flood sediments (Takuma gravel bed) from Aso volcano, Japan, and tephric loess deposits overlying the gravel bed. The poly-mineral fine grains (4–11 μm) from loess deposits were measured with pulsed optically stimulated luminescence (pulsed OSL) and post-IR infrared stimulated luminescence (pIRIR) methods, whereas the Takuma gravel bed containing no quartz, was measured with IRSL and pIRIR methods using sand sized (150–200 μm) plagioclase. The loess deposits date back at least to ~50 ka by consistent IRSL, pIRIR and pulsed OSL ages from the lowermost part of the loess deposits from one section. The ages obtained from the bottom part of the other loess section are not consistent each other. However, we consider that the pIRIR age (72±6 ka) which showed negligible anomalous fading is most reliable, and regard as a preliminary minimum age of the Takuma gravel bed. The equivalent doses (De) for the plagioclase from the Takuma gravel bed have a narrow distribution and the weighted mean of the three samples yield an age of 89±3 ka. This age is in agreement with the last caldera-forming eruption of Aso volcano (~87 ka) and it is likely that the pIRIR signal has not been bleached before the deposition. IRSL dating without applying pIRIR using small aliquots was also conducted, however, the IRSL signal shows no clear evidence of an additional bleaching during the event of outburst flood from the caldera lake. 相似文献
17.
Daniel Richter Jean-Jacques Hublin Jacques Jaubert Shannon P. McPherron Marie Soressi Jean-Pierre Texier 《Journal of archaeological science》2013,40(2):1176-1185
Thermoluminescence dating of heated flint artefacts from the Middle Palaeolithic sequence of Chez-Pinaud Jonzac (France) places an assemblage of Quina type Mousterian into MIS 4, while the overlying assemblage of Denticulate Mousterian which is followed by two layers with Mousterian of Acheulean Tradition are all assigned to MIS 3. TL dating is used to verify the mixed nature of deposits from which diagnostic Middle as well as Upper Palaeolithic tools were recovered. The TL ages are significantly different for samples from this layer and broadly agree with the archaeological attributions. While the study is generally limited by the low number of heated samples available, a correlation with a generalized chronostratigraphic sequence is possible by including proxy data from the faunal remains associated with the lithic assemblages in question. The Quina Mousterian in southwestern France, therefore, can be placed by chronometric dating methods in MIS 4 to MIS 3. 相似文献
18.
熄灭率是研究瓷器辐照熄灭特性的一个重要参数,也是衡量一件古瓷器能否用热释光前剂量技术测定的一个重要条件.如果一件瓷器的熄灭率太低,这件瓷器就不能用前剂量技术测定年代,或测定得到的年代结果误差会很大.为此,本工作对中国最早的青瓷——浙江慈溪上林湖唐代、五代及宋代的10个越窑古窑址的78件青瓷样品进行了辐照熄灭率测试研究.测试结果分别获得了各测定样品的“辐照熄灭率”.越窑青瓷样品的平均熄灭率为11.38%,这样的熄灭率保证了热释光灵敏度曲线测量时有足够的分辨率,也保证了应用热释光前剂量熄灭法测定越窑瓷器样品年代结果的准确性. 相似文献
19.
Different post-IR Infrared Stimulated Luminescence (IRSL) approaches are applied to sediments from a Holocene coastal foredune sequence on Ruhnu Island in the eastern Baltic Sea. The comparison of D e-values and ages determined by the different approaches is complimented by fading and bleaching experiments. The fading experiments imply strong fading of IRSL (50°C) signals and no fading of any of the post-IR IRSL signals, but this is not confirmed by the determined D e-values. In fact, post-IR IRSL (150°C) D e-values agree within errors with those calculated for IRSL (50°C). From the bleaching experiments it is inferred that the higher values observed for post-IR IRSL at more elevated stimulation temperatures (225°C/290°C) are likely related to either thermal transfer and/or slow-to-bleach components within the signal. For the dating of the Holocene foredune sequence of Ruhnu Island, the post-IR IRSL (150°C) approach is preferred and these agree with the limited independent age control available from radiocarbon dating. Accordingly, the sequence formed between ca. 7.0 ka and 2.5 ka ago. 相似文献
20.
Examining quartz OSL age underestimation for loess samples from Luochuan in the Chinese Loess Plateau 总被引:1,自引:0,他引:1
When using quartz OSL to date loess samples from the Chinese Loess Plateau, it has been reported that the agreement between OSL ages and the independent ages is limited to the samples younger than ~70 ka with a corresponding De of ~230 Gy, and a sample with an expected age of 780 ka was dated to 107 ka, corresponding to 403 Gy. The growth curves of these samples do not saturate at doses of 700 Gy, and a linear growth part was observed for doses higher than 200 Gy. However, the maximum measured age of ~100 ka imply that the De determined using this linear part of a growth curve could be problematic, or that the quartz OSL signal is not as stable as previously thought and has a barrier age of ~100 ka. In the current study, we examine the reasons for the age underestimation. We examined the shape of growth curves, anomalous fading, thermal stability, etc. The results show that, for the loess samples examined, quartz OSL does not fade anomalously, and the barrier age of ~100 ka is due to the fact that the OSL signals are less thermally stable, the lifetime of 0.311 Ma at 20°C obtained is much smaller than those for quartz samples from other regions such as Australia (~100 Ma). 相似文献