共查询到20条相似文献，搜索用时 188 毫秒
1.
This study focuses on characterizing the thermoluminescence (TL) and optically stimulated luminescence (OSL) of quartz in burnt clay, pottery, and the sediments unearthed from a Neolithic site, the Beicun site of the Liangzhu culture. It shows that the initial OSL signals (within 0.8 s) of most burnt clay and pottery sherds are not dominated by the fast component. Results of a heating simulation experiment of sediment quartz show that annealing at temperatures exceeding 600–800 °C decreased the proportion of the fast component in the initial signal slightly. In addition, the proportion of the medium component in the later signal (0.8–5 s) increased significantly, resulting in a decrease in the Fast Ratio value. Therefore, high annealing temperature may be an important reason for the slow decay rate of OSL signals of the burnt clay and pottery samples. The De(t) plot shows that most of the samples have thermally stable OSL component signals, which have no significant effect on the final OSL ages. The single-aliquot regenerative-dose (SAR) protocol was used to determine the OSL and TL ages for chunk burnt clay and pottery sherds. The high-precision age of the last archaeological heating event, such as sacrifice, burning, or domestic firing, can be obtained by determining the TL and OSL ages of a homogeneous chunk of burnt clay. The OSL results are consistent with the 14C age of carbon chips extracted from burnt clay. The age of the Beicun site is finally determined to be approximately 5000–5300 BP (BP represents before 2020), belonging to the early period of the Liangzhu culture. 相似文献
2.
3.
Electron spin resonance (ESR) dating of optically bleached quartz grains was performed on three sediment samples collected from the Middle Palaeolithic site of Cuesta de la Bajada (Spain). A standard multiple grain and multiple aliquot additive dose procedure was employed, and both the Al and Ti centres were measured as part of the multiple centres approach.ESR age estimates obtained for the three samples indicate that the Al centre provides a maximum possible chronology, as the Ti centres show that the Al signal was likely not systematically reset to its residual level during sediment transport. A direct comparison between ESR ages based on the Ti centres and single grain optically stimulated luminescence (OSL) ages from samples collected nearby shows broadly consistent results. The Ti-H centre also appears to provide suitable chronologies for at least two of the three Middle Pleistocene samples studied here. Surprisingly, the only sample showing consistent ESR ages between the Al and Ti centres appears to be overestimated in comparison with the Ti-centre and OSL ages derived from the other two samples. This indicates either incomplete bleaching of both the Al and Ti centres for this sample, or unexpected impacts of other sources of De uncertainty, such as multi-grain averaging effects. The ESR dating results overall indicate that the archaeological sequence of Cuesta de la Bajada CB-3 is most likely correlated to either MIS 7 or 9. 相似文献
4.
Infrared-stimulated luminescence dating (IRSL) was applied on pottery sherds from the Mailhot-Curran archaeological site (BgFn-2), a Late Woodland period village located in the Saint-Anicet region, southern Québec (Canada). This site witnessed the presence of St. Lawrence Iroquoians and is thought to have been occupied roughly 500 years ago. The main goal of this study is to chronologically constrain the occupation of this site in order to establish a fine chronological sequence for the occupations of various sites found in this area. The IRSL is used to complement previous dating methods used for Mailhot-Curran (radiocarbon and seriation of the archaeological remains).Dating results are reported for ten samples of local ceramics made from Quaternary Champlain Sea clay. Luminescence dating on fine grains was preferentially used, since feldspar luminescence typically emit a decent luminescence signal. Although the latter was rather dim, anomalous fading was measured and luminescence ages were successfully corrected. It is therefore possible to validate the occupation age of this site. 相似文献
5.
Many archaeological sites were excavated in China, but rarely in the adjacent coastal areas. An archaeological site at Huangniliang in the coastal area of Shandong Province, northern China was excavated in 2013. Abundant stone artifacts including hammers, cores, flakes, chunks, and retouched tools are found in the silty aeolian sediments. In this study, optically stimulated luminescence (OSL) technique was employed to establish the chronological framework of the site. Medium-grained (45–63 μm) quartz was extracted from six sediment samples for dating. The equivalent doses obtained with the single-aliquot regenerative-dose (SAR) protocol are shown to increase with depth. Three samples from the stone-tool containing layer yield OSL ages ranging from 54 ka to 59 ka, providing the earliest geochronological evidence for the presence of humans in the eastern coast of Shandong peninsula during the early period of Marine Isotope Stage (MIS) 3. 相似文献
6.
Little work has been undertaken on combined dating of sedimentary quartz grains using electron spin resonance (ESR) and optically stimulated luminescence (OSL) techniques in Australia. This study aims to assess the suitability of a combined ESR and OSL dating approach for establishing improved chronologies of Middle-Late Pleistocene deposits within the Naracoorte Cave Complex (NCC), South Australia. Here, we apply ESR and OSL dating in tandem to a series of samples collected from three different NCC sites: Whale Bone, Specimen and Alexandra cave. ESR quartz dating focuses on the multi-centre (MC) approach, which involves comparative evaluations of Al and Ti centre signals, while paired luminescence dating focuses on single-grain OSL analysis and includes examination of multi-grain averaging effects. The comparative ESR-OSL dating results exhibit broad agreement for deposits spanning 50–150 thousand years, with either the Ti–H or Al centre ages overlapping with paired OSL ages at 2σ in nearly all cases. MC ESR evaluations (Al v Ti–Li v Ti–H age assessments) indicate incomplete resetting of the bleachable Al centre signal for a small number of samples. Two-thirds of samples exhibit Ti–Li ages that are significantly older than corresponding Al centre ages, which is unexpected from a bleaching kinetics perspective and may indicate a broader reliability issue for Ti–Li palaeodose evaluation with these particular samples. Our findings: (i) support the applicability of both palaeodosimetric dating methods in this depositional setting; (ii) highlight the merits of applying combined ESR-OSL analyses in tandem, and; (iii) provide one of the first reliable evaluations of quartz ESR MC dating for samples with natural dose ranges as low as only a few tens of Gy. These results show that the Whale Bone, Specimen and Alexandra cave sites are temporally related and can be used to derive multi-site reconstructions of faunal assemblages and palaeoenvironmental history. 相似文献
7.
Luminescence dating has become a key tool in studies of the Quaternary. The typically stable luminescence response of quartz grains and the absence of a significant internal dose, make quartz minerals the preferred dosimeter for monitoring the burial dose in sediments. Unfortunately, the reliability of conventional OSL (optically stimulated luminescence) dating, based on blue stimulation, can be compromised when the luminescence decay is not dominated by a rapidly decaying and stable part of the luminescence signal (i.e. the fast component). On the other hand, standard methods in luminescence dating are limited to ages of a few hundred kiloyears. In this study, violet stimulated luminescence (VSL) has been used as a means to overcome both problems, applied to a series of colluvial deposits in the Atacama Desert, Chile. Quartz from this region, characterized by poor blue-OSL response, showed a reproducible and stable VSL signal capable of recovering given doses up to ∼500 Gy and a saturation dose twice as high as conventional OSL. The VSL response from these samples has been studied in detail and the estimated ages have been compared with an already established chronology for the same site, based on IRSL of potassium feldspar single grains. Results agree for the dose range of the profile studied, ∼100–250 Gy, equivalent to ages of 29–79 ka confirming the suitability of VSL for dating sedimentary quartz with unreliable blue-OSL response and to extend the age range of conventional OSL dating. 相似文献
8.
Optically stimulated luminescence (OSL) dating was applied to quartz samples recovered from the gravel sediments of deformed marine terrace at the Suryum site, southeastern Korea, but has yielded stratigraphically inconsistent ages. Micromorphological, chemical, and mineralogical analyses of the gravels indicate the possible influence of chemical weathering on the apparent OSL ages. In the course of weathering after emerging from beach environments, originally permeable gravels underwent infilling by halloysite-rich clays in their voids, export and import of radioactive elements, and loss of mechanical strength with the creation of a porosity within pebbles. Calculation based on the evolution of the weathering profile showed a severe fluctuation of dose rate caused by the change of water content and radioactive element concentrations. Samples recovered from the weathering profile inevitably include quartz grains derived from mechanically weakened pebbles or illuviated from the upper layer, making it difficult to determine the equivalent dose (De) values of exclusively depositional quartz sands. Quantitative evaluation of the change of fabric and chemistry of the sediments on the basis of pedologic insight significantly aids in the derivation of OSL ages consistent with geomorphology and other independent age controls. 相似文献
9.
Recent developments have opened up the possibilities of using potassium feldspar for dating Pleistocene sediments; a stable (less-fading) part of the infrared stimulated luminescence (IRSL) signal can be selected by largely depleting the unstable part of the IR signal, using a combination of thermal and IR stimulation: post IR-IRSL dating (pIR-IRSL).This study aims to test the validity of pIR-IRSL dating on feldspars. We obtained pIR-IRSL ages on a large suite of samples from several locations in the Netherlands area, covering a wide range of depositional environments and ages. Age control was provided by quartz optically stimulated luminescence (OSL) ages on the same samples; these ages were shown to accord with geological age constraints. Comparison with IRSL ages enabled us to evaluate the improvement that pIR-IRSL dating provides over conventional IRSL methods.The majority of feldspar ages obtained with pIR-IRSL showed good agreement with both the quartz OSL ages and the geological age constraints. Our study demonstrates that pIR-IRSL dating is more robust than conventional IRSL and should be the method of choice in feldspar luminescence dating of Pleistocene sediments. 相似文献
10.
Loess and fluvial sand are important materials for dating river terraces and alluvial fans. This study focuses on the methodological aspects of dating loess and fluvial deposits from the northern flank of the Tian Shan range, China, using sand-sized quartz and potassium (K) feldspar. Luminescence characteristics of quartz and K-feldspar were studied for searching suitable dating procedures. Our results indicate that 1) most quartz aliquots were contaminated by feldspar, and were dated using a post-infrared optically stimulated luminescence (post-IR OSL) procedure. A Fast ratio acceptance threshold of 15 can be applied to select these aliquots with post-IR OSL signals dominated by quartz OSL; 2) the multi-elevated-temperature post-IR IR stimulated luminescence (MET-pIRIR) procedures are applicable for K-feldspar. A test dose of ∼30% of the natural dose is appropriate for dating of older (>10 ka) samples. An Age (T, t) plateau test can be used to evaluate the dating results; 3) for the loess samples, both quartz and K-feldspar were well bleached and are suitable for dating. Dating using K-feldspar is preferred for its higher efficiency; 4) for the fluvial sand samples, only the quartz grains were fully bleached. Single-aliquot dating of quartz gives reliable ages. 相似文献
11.
The Qinghai-Tibetan Plateau is an important area for the study of Quaternary glaciation. Optically stimulated luminescence (OSL) dating has the potential to contribute to the chronology of glaciation in this region, but it is important to assess the accuracy of OSL dating of these glacial sediments. In this study, single grain quartz OSL signals are examined for five glacial samples collected from the moraines outside the Baiyu Valley, southeastern Tibet. The quartz grains exhibit poor luminescence characteristics, with a small proportion of grains passing the screening criteria. Grains which pass the screening criteria have relatively low signal intensity, leading to De values with large uncertainties. MAM and CAM were used to determine De values for these samples. The OSL ages are consistent with the sequence of events derived from the geomorphological relationship of the samples, and also with previous published radiocarbon ages. However, it is more difficult to reconcile the OSL ages and the terrestrial cosmogenic nuclide (TCN) 10Be ages. Analysis of both single grain quartz OSL data and TCN 10Be data is complex in this area. Further work is required to increase confidence in the OSL ages generated for the glacial sediments from this region. 相似文献
12.
Raised beach sand deposits along the southeastern coast of Norway were dated by optical (OSL) and infrared stimulated luminescence (IRSL) and the quartz and K-feldspar luminescence characteristics were described. Due to the poor quartz luminescence characteristics, only a limited number of samples were suitable for OSL dating. More promising are the K-feldspar extracts, with typical K-feldspar luminescence characteristics and no sign of fading. For equivalent dose (De) determination, sand-size quartz and feldspar extracts were used, applying a single aliquot regenerative (SAR) protocol. Both, OSL and IRSL De estimates show a wide distribution, unexpected for beach deposits. The calculated OSL and IRSL age estimates were generally in good agreement and the correctness of the ages was confirmed by independent age control. Because only a limited number of the quartz samples were suitable for OSL dating, IRSL dating of the K-feldspar represents an alternative to OSL quartz dating. 相似文献
13.
《Quaternary Geochronology》2008,3(1-2):114-136
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 °C TL peak and the associated slowly bleached ‘S2’ OSL component. Longer OSL stimulation durations are adopted in the De 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 14C 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. 相似文献
14.
Luminescence dating is one of the leading techniques to establish chronologies for loess-palaeosol sequences and has been successfully applied to different minerals and grain size fractions. Using optical stimulated luminescence (OSL) from quartz, we present for the first time a high resolution chronology for the loess section Ostrau in Saxony/Germany. We compare OSL ages derived from two different grain size fractions, coarse (90–200 μm) and the fine grain (4–11 μm) separates. Our results show that the loess section is divided into two parts, separated by a hiatus. OSL samples from the upper part of the loess section show equivalent doses of De < 100 Gy. De values >180 Gy are observed for the lower part of the loess section. The coarse and fine grain ages agree and also fit to the litho- and pedostratigraphy for the upper part of the profile. For the lower part of the profile the coarse grained quartz OSL is in saturation. The fine grained quartz OSL is not saturated but it appears that the fine grain OSL ages underestimate the sedimentation age. Approaches to explain the De differences between the grain size fractions are presented (e.g. post-depositional translocation, dosimetry). A modified SAR protocol for the fine grain fraction produced ages that are in good agreement with expected ages based on litho- and pedostratigraphy. Although further investigations are needed, our results show the suitability of the Saxonian loess belt for OSL dating. 相似文献
15.
Xiao Fu Jia-Fu Zhang Duo-Wen Mo Chen-Xi Shi Hui Liu Yi-Yin Li Li-Ping Zhou 《Quaternary Geochronology》2010,5(2-3):353-359
The Qujialing site is a representative Neolithic archaeological site in the middle reaches of the Yangtze River, China. Absence of suitable material for radiocarbon dating in this region makes the timing of the similar sites difficult. Here we applied optically stimulated luminescence (OSL–SAR) and thermoluminescence (TL–SAR) techniques to date the archaeological and natural deposits from the Qujialing site with known age, testing the techniques on samples at archaeological sites in this region. The results showed that the luminescence properties of quartz from sediment and baked earth samples are very similar. The quartz OSL ages obtained for a sediment sample and a baked earth sample from the cultural layer are 5.4 ± 0.3 and 5.1 ± 0.3 ka, respectively. The quartz TL age of the baked earth sample is 5.6 ± 0.5 ka. These dates are consistent with the calibrated radiocarbon ages (4.9 ± 0.1 and 5.1 ± 0.1 ka cal BP (±1σ)) of the two charcoal samples from the cultural layer at a nearby locality, and are also in agreement with the age of Qujialing culture period. The results indicate that the OSL dating techniques can be applied to date similar archaeological sites in the middle reaches of the Yangtze River, China. 相似文献
16.
Dose saturation represents a fundamental limitation for obtaining finite optically stimulated luminescence (OSL) quartz ages over Middle Pleistocene timescales. Single-grain OSL studies typically reveal significant intra- and inter-sample variability in quartz dose saturation properties at the individual grain level. This enhanced variability may offer the potential to obtain extended-range chronologies exceeding the traditional upper age limits of multiple-grain OSL dating. However, there have been relatively few detailed assessments of single-grain OSL properties over high dose ranges. In this study we investigate extended-range single-grain OSL dating potential at Cuesta de la Bajada, one of the most important Ancient Middle Palaeolithic sites in the Iberian Peninsula. The quartz samples from this site exhibit exceptional dose saturation properties and contain significant populations of individual ‘supergrains’ with bright OSL signals, very high characteristic saturation dose (D0) limits of 200 to >600 Gy, and dose-response curves that closely conform to single saturating exponential functions. Assessments of OSL signal composition and the ability to successfully recover a known laboratory dose of 470 Gy support the potential for obtaining high equivalent dose (De) values with reasonable fitting uncertainties. A series of novel sensitivity tests are used to assess potential biases in supergrain De estimation over high dose ranges related to (i) thermally transferred signal contributions, (ii) choice of dose-response curve fitting function, and (iii) insufficient dose saturation properties of individual grains. The single-grain De values obtained using the standard quality assurance criteria and novel sensitivity tests are consistent at 2σ, and are in agreement with quartz Ti-centre ages obtained on two of three paired electron spin resonance (ESR) samples collected from Cuesta de la Bajada. These comparisons support the suitability of our single-grain OSL results and suggest there may be good potential for using quartz supergrains to establish extended-range chronologies at some Middle Pleistocene sites. Comparisons with other single-grain OSL studies across the Iberian central plains suggest that favourable dose saturation properties may be influenced by regional-scale geological controls. The importance of undertaking single-grain OSL dating at Cuesta de la Bajada is also demonstrated by the results of synthetic aliquot experiments, which reveal multiple-grain age offsets of 60–170 ka when unsuitable grain types are inadvertently included in the final age calculations. The single-grain OSL results indicate that the main archaeological horizon at Cuesta de la Bajada (unit CB3) accumulated between 264 ± 22 and 293 ± 24 ka. These ages are consistent with the chronologies of other key early Middle Palaeolithic sites in the region (Ambrona AS6 and Gran Dolina TD10) and indicate that the Ancient Middle Palaeolithic techno-complex likely spread across Iberia from at least Marine Isotope Stage 9 onwards. 相似文献
17.
Similar to the loess deposits on the Chinese Loess Plateau (CLP), a reliable chronology plays also an important role in revisiting past climate and environment changes recorded by the loess in Central Asia. Previously, a few luminescence and 14C ages, mainly covering the last glacial, were obtained for several loess sections in Central Asia, which are often controversial. Until now, there is still a lack of reliable high-resolution chronologies covering the late Pleistocene, especially the Holocene. Here, the fine-grained (4–11 μm) quartz single-aliquot regenerative-dose (SAR) optically stimulated luminescence (OSL) dating protocol is used to establish a detailed chronology of the uppermost part (∼5 m) of Talede loess in the Ili Basin Central Asia. Conventional tests of the SAR protocol and the general luminescence characteristics indicate that this protocol is suitable for dating the Talede loess. Finally, 15 closely-spaced quartz OSL ages, ranging from 0.72 ± 0.05 to 28.9 ± 2.12 ka and with no reversals, were obtained. Consistent with previous studies in the Ili Basin, two of the three 14C ages show discrepancy when compared with quartz OSL ages for the Talede loess section. The constructed OSL chronology of the Talede loess reveals that the dust accumulation is rapid during marine isotope stage (MIS) 2, especially during the Last Glacial Maximum (LGM), and is also continuous during the Holocene, with the dust accumulation rate exhibiting a relatively low level and an increasing trend. Comparison of the dust accumulation at Talede with that at other sites in the Ili Basin indicates that the rapid dust accumulation during the LGM is not universal, and the slow dust accumulation during the Holocene is probably true for the entire Ili Basin. Comparison of different grain sized quartz OSL ages from Central Asian loess show characteristics of both consistency and inconsistency, which needs to be further investigated. 相似文献
18.
Optically stimulated luminescence dating of a Holocene beach ridge plain in Northern Jutland, Denmark 总被引：1，自引：0，他引：1
Asger Nielsen Andrew S. Murray Morten Pejrup Bo Elberling 《Quaternary Geochronology》2006,1(4):305-312
This study presents results from 20 optically stimulated luminescence (OSL) ages from one of the world's largest beach ridge plains, the Jerup beach ridge plain at the base of the Skagen Spit in the northernmost part of Jutland, Denmark. The OSL ages were obtained using quartz and a SAR protocol, and used to establish a chronology for the beach ridge plain and for the underlying coastal plain. The accuracy of the chronology is tested both by laboratory tests (recuperation, recycling ratio and dose recovery) and by comparison with independent age controls, e.g. previously reported radiocarbon dates, map sources, anecdotal evidence and settlement names. It is concluded that the OSL signals are internally consistent, and that the derived OSL ages are in good agreement with a large range of independent age controls. The ridge plain is shown to cover a time span from 1000 to 2700 years ago; this chronology is more detailed and precise than those previously available, and gives an average beach ridge formation rate of 15 yr/ridge and an average lateral migration rate of 2.0 m/yr. This study adds to the growing knowledge that OSL dating has a large potential for establishing detailed and precise chronologies in coastal marine sediments, including beach ridges. 相似文献
19.
Although there has been significant advancement of OSL (optically stimulated luminescence) dating of quartz and feldspar over the past decade, the luminescence characteristics of quartz grains in many tectonically active areas are not suitable for accurate age determinations using this technique. This study investigates the reasons for this unsuitability and tests a new measurement protocol (ITL), which appears more promising. At two sites along the central Garlock fault in the Mojave Desert, California, USA, samples collected for OSL dating for this study have proven problematic. At the El Paso Peaks (EPP) trench site, a sequence of OSL samples was collected from sandy units with a well-established radiocarbon chronology, providing the opportunity to assess different approaches and optimize our luminescence dating procedures. At Christmas Canyon West (CCW), where future Garlock fault slip rate studies will be conducted using luminescence dating, samples were collected to assess the luminescence characteristics of both quartz and feldspar in this environment. At both sites, signals from quartz and K-feldspar grains are consistently dim. At EPP, quartz results provide age underestimates, while K-feldspar IRSL yields erratic values; the causes of this problematic behavior are unclear. Preliminary minimum isothermal thermoluminescence (ITL) signals of K-feldspar measured during preheating appear to be consistent with the radiocarbon age estimates, demonstrating potential for accurate age determination in this kind of environment using this protocol. 相似文献
20.
In this study we test, for the first time, the potential of an elevated temperature post-IR IR (pIRIR290) SAR protocol for the dating of young heated artefacts. Seven heated stones and seven potshards were collected from three different archaeological sites in Denmark: one site from the early Pre-Roman Iron Age 200 BC to AD 100, and two from the Viking period between AD 800 and 1200.We first derive quartz OSL ages for these samples, to support the archaeological age control. The luminescence characteristics of the pIRIR290 signal are then investigated; in particular the dose recovery ratios are shown to be close to unity. The performance of the feldspar pIRIR290 protocol is then examined by comparing the pIRIR290 ages with those based on the quartz OSL signal; the average ratio of pIRIR290 to OSL ages is 1.14 ± 0.05 (n = 14) and there is some suggestion that the possible overestimation of the feldspar ages compared to quartz is only of significance for the heated stone samples. Nevertheless, there is no indication of incomplete heating of the stones; the ratios of De derived from the IR50 and pIRIR290 signals are independent of sample type, and consistent with complete resetting by heating. Comparison with the archaeological age control is not able to identify whether quartz or feldspar provides the most reliable dating signal. 相似文献