Holocene aeolian dynamics in the European sand‐belt as indicated by geochronological data

Aeolian sands are widespread in the European sand‐belt. While there is a consensus about the timing of increased aeolian activity and, in contrast, of surface stabilization during the Lateglacial, knowledge about Holocene aeolian dynamics is still very sparse. It is generally assumed that aeolian processes have been closely connected to human activities since at least the Neolithic period. A compilation of 189 luminescence dates from aeolian sands of Holocene age and 301 ¹⁴C‐dates from palaeo‐surfaces, comprising palaeosols, buried peats and archaeological features from the whole sand‐belt, is plotted as histograms and kernel density plots and divided into sub‐phases by cluster analysis. This is also done separately for the dates from the areas west and east of the river Elbe. Our results show that aeolian activity did not cease with the end of the Younger Dryas but continued in the whole European sand‐belt until the Mid‐Atlantic (c. 6500 a BP), presenting evidence of vegetation‐free areas at least at the local scale. During the subsequent time period evidence of aeolian sedimentation is sparse, and surface stabilization is indicated by a cluster of palaeo‐surfaces ascribed to the early Subboreal (c. 5000 cal. a BP). The agglomeration of luminescence ages around 4000 years is probably connected with intensified land use during the Late Neolithic. Younger phases of aeolian sedimentation are indicated by clusters of luminescence ages around 1800 years, a group of luminescence ages from the Netherlands and NW Germany around 900 years, and a group of ages around 680 years in Germany. Among the dates from palaeo‐surfaces, clusters were identified around 2700, 1300 and 900 cal. a BP as well as around 690 cal. a BP in the western part and 610 cal. a BP in the eastern part of the sand‐belt. The clusters within the luminescence ages and the ¹⁴C‐dates coincide with phases where increased human impact can be deduced from archaeological and historical sources as well as from environmental history.     

Chronology of Murrumbidgee River palaeochannels on the Riverine Plain,southeastern Australia

Four major periods of palaeochannel activity have been identified on the Murrumbidgee sector of the Riverine Plain of southeastern Australia. On the basis of stratigraphic information the channels reveal a picture of changing flow conditions during the last full glacial cycle. The ages of the periods were determined from nearly 40 thermoluminescence dates on surficial fluvial and aeolian sediments. These are named the Coleambally phase, which occurred from 105 to 80 ka (the mid- to latter part of Oxygen Isotope Stage 5), the Kerarbury phase from 55 to 35 ka (Stage 3), the Gum Creek phase from 35 to 25 ka (late Stage 3 to early Stage 2) and the Yanco phase from 20 to 13 ka (late Stage 2). The present flow regime was established by about 12 ka (Stage 1). The first two phases correlate with episodes of enhanced fluvial activity in northern and central Australia and with reduced dust activity globally. The phases in Stage 2 appear to be associated with seasonal snow melt and increased peak flows in periods flanking the Last Glacial Maximum. Source-bordering aeolian dunes associated with the Coleambally, Kerarbury and Yanco phases were found, however, the TL dates show that some have undergone aeolian reworking. Thermoluminescence dating and fluvial stratigraphy have revealed a detailed picture of Late Quaternary climate and flow regime changes that has the potential to extend to identified deposits stratigraphically older than those described here.     

OSL and TL dating of buried podsols and overlying sands in Ostrobothnia,western Finland

In Ostrobothnia, western Finland, buried fossil soils have been recognised in a number of places in the sandy sediments that occur between glaciofluvial deposits and overlying till. Samples from the soil horizons as well as below and above them were taken for optically stimulated luminescence (OSL) dating. The same sites were also sampled for thermoluminescence (TL) dating. Altogether five TL dates and seventeen OSL dates were obtained. The OSL dates can be grouped into two age classes, (i) 120-163 ka and (ii) 76-106 ka, whereas all TL dates are of the order 135-155 ka. A comparison between the results obtained from the two dating methods shows that OSL dates are generally younger than the TL dates for the same sample. The discrepancy may arise partly from problems of setting a correct residual level in TL dating. If this is the case then the TL dates may indicate an upper limit for the true age. The results support the geological interpretation that the fossil soils were formed during the last interglacial, that the soil-forming processes possibly also continued during the first Early Weichselian stadial and interstadial (Brørup sensu lato), and that in general the till-covered glaciofluvial sequences, interpreted as eskers in Ostrobothnia, were deposited during the Saalian or Early Weichselian deglaciation.     

A review of current research on TL dating of loess

The thick loess deposits of China, Central Europe and North America are particularly suitable for the application of the thermoluminescence (TL) dating method because individual grains are likely to have travelled large distances and thus been well exposed to light before deposition. Wind-blown silt grains collected close to glacial rivers in Alaska have been shown to give a ‘zero age’ of not more than 2 ka, demonstrating the efficiency of the zeroing mechanism.Differences in laboratory procedures can cause differences in the TL ages reported, particularly for loess over 100 ka. TL ages for interstadial soils in Europe are in agreement with the very few radiocarbon dates on reliable material, such as charcoal. On the other hand TL dates from sites in Belgium and north-western Germany indicate that the previously accepted chronology, which was based on two radiocarbon dates on humic-rich sediments, is incorrect.The use of the ‘last interglacial’ palaeosol for assessing the TL dates on loess above and below it is limited by the uncertainty in the timing of termination of soil-forming processes; 107 and 71 ka are the limits suggested by the astronomically-derived time scale. Results on deposits from China, North America, Alaska and Europe are discussed in this context.     

The onset of dune formation in the Strzelecki Desert,South Australia

This study is concerned with the Late Quaternary climatic chronology of the Strzelecki Desert dunefields in central Australia. The sand ridges comprise layers of quartz sand, some of which include palaeosol horizons with carbonated rootlets providing excellent opportunity for dating of alternations of dune building and stability by using optically stimulated luminescence (OSL). Deduced from the OSL age of the oldest aeolian layer dated, we conclude that the onset of aridity dates back to at least ∼65 ka. Older phases of aeolian activity though, following a fluvial depositional phase 160 ka ago, cannot be excluded, although no aeolian layers giving evidence for this have been found in the two dunes dated here. Unconsolidated dune sands in the upper part of one section with Late Holocene (4 ka to modern) depositional ages indicate a reactivation of the dunefield in recent times.From the crosscheck of ¹⁴C ages of the carbonated rootlets with OSL results it is concluded that under the given environmental conditions radiocarbon dating of the calcareous rootlets is not able to provide reliable ages for the phase of soil development.     

Reconstruction of the late Quaternary environment of the lower Luni Plains,Thar Desert,India

Geomorphological processes in the Thar Desert of India are largely climate driven. In the lower reaches of the River Luni (the only major drainage system in the Thar Desert) a fluvio‐aeolian sequence was located at a site called Khudala. Sediments of this sequence represented a variety of depositional environments, namely aeolian, fluvially reworked aeolian, overbank deposits, gravels, and occasional evidence of pedogenesis. This provided a good opportunity to study aeolian–fluvial interaction in the region and for deducing climatic records. From the luminescence dating standpoint these sequences offered a good opportunity for a comparative study of thermoluminescence (TL), blue‐green light stimulated luminescence (BGSL) and infrared light stimulated luminescence (IRSL) on different mineral separates of identical provenance but deposited under different environments. Broadly, within experimental errors, the TL ages agreed with BGSL and IRSL ages on aeolian sands, but differed substantially in the case of fluvially reworked and proximally deposited sands and silts. The sequence provided a record spanning more than 100 ka, with an aeolian phase at > 100 ka, a channel activation phase between 70 and 30 ka and a phase of climate instability between 13 and 8 ka. This appears consistent with the records of monsoon performance during this period, which includes the Younger Dryas. It is also inferred that during the Last Glacial epoch, geomorphological processes in the Thar (both aeolian and fluvial) were dormant largely on account of their relationship with the southwest monsoon. Copyright © 2001 John Wiley & Sons, Ltd.     

Late Devensian and Holocene depositional environments associated with the coversand around Caistor, north Lincolnshire, UK

Sand deposits described at three sites near Caistor, north Lincolnshire (UK), provide a record of Late Devensian (Late Weichselian) to Holocene palaeoenvironments at the western margin of the European sand belt. Thermoluminescence (TL) and radiocarbon analyses provide for the first time a chronological framework for the demise of proglacial Lake Humber and the onset of coversand deposition. The reconstructed palaeoenvironmental history suggests that proglacial Lake Humber had receded from its initial high-level stand before c. 18 ka, exposing the lake floor to periglacial conditions marked by the development of thermal contraction cracks. In the period between c. 18 and 14 ka, sand-depositional processes changed from dominantly fluvial to aeolian. The fluvial activity was possibly a consequence of ameliorating winter climates between c. 17 and 16 ka. The aeolian coversand deposition in this period has not been previously recognized in Britain and correlates with the Older Coversand II and Younger Coversand I deposits elsewhere in the European sand belt. Peat accumulation followed during the Windermere (Bølling/Allerød) Interstadial and early part of the Loch Lomond Stadial (Younger Dryas) before regionally extensive coversand deposition took place in the later part of the Loch Lomond Stadial. This coversand correlates with the widespread Younger Coversand II deposits found both within the UK and across the European sand belt. The Holocene has been characterized by widespread stability with the development of soils on the coversand punctuated with periods of localized reworking through to the present day.     

Thermoluminescence dating of sediments from Oulainen and Vimpeli, Ostrobothnia, Finland

Mean ages of 94 ka and 121 ka were obtained at Oulainen for two sand layers situated above and below an organic deposit previously correlated with the Brörup interstadial. At Vimpeli, TL dates obtained for sand layers embedded in an organic deposit suggest an age for this deposit of 107 ka. The uncertainty in this result is considerable, however. Problems encountered in dating these sediments and the reliability of the results are discussed.     

Luminescence dating of Holocene spit deposits: An example from Skagen Odde, Denmark

Clemmensen, L. B. & Murray, A. S. 2009: Luminescence dating of Holocene spit deposits: An example from Skagen Odde, Denmark. Boreas , 10.1111/j.1502-3885.2009.00110.x. ISSN 0300-9483.
Skagen Odde is a large, active spit system in northern Denmark that started to form about 7200 years ago. Models for spit growth have usually relied on radiocarbon-dating of swale peat (Martørv). In this study, we date the spit deposits at three sites directly using Optically Stimulated Luminescence (OSL) to obtain supplementary age control on spit development. The spit deposits consist of a lowermost succession of shoreface, beach and backshore aeolian deposits topped by a swale peat and followed by an uppermost succession of aeolian sand sheet and dune deposits. The ages of the shallow marine, beach and backshore aeolian deposits at the main study site are indistinguishable, implying good resetting of the shallow marine deposits; the average age of 4640±250 years compares well with earlier model predictions based on radiocarbon-dating of swale peat. Aeolian sand extracted from the uppermost part of the swale peat at this site provides OSL ages of between 1600 and 2500 years, in good agreement with a calibrated AMS age from the same level of 2330–2200 years. The uppermost aeolian succession consists of two units separated by a thin palaeosol, and the aeolian units have OSL ages of about 1500 years and younger than 130 years. Lowermost spit deposits at the two additional sites have average ages of 5010±240 and 3730±190, respectively, supporting the existing chronology for spit growth based on radiocarbon-dating.     

早期智人古老型——智人大荔亚种的年代

文中综合研究了有关大荔人头骨化石的产出地层、伴随出现的古生物化石、古气候演变的条件等 ,结合用热释光技术测定地层年代这一基本思路 ,将大荔人的生存年代确定为不老于 30万年。     

First evidence of an interglacial lake of Eemian age in northeast Italy

This paper assesses the age of the Tagliamento Morainic Amphitheatre (northeast Italy), one of the largest morainic bodies in the piedmont area of northern Italy, using new stratigraphical and thermoluminescence (TL) data obtained from a site located on the inner flank of the amphitheatre. Two samples from a 12-m-thick stratum of fluviolacustrine, non-varved, fine sand provided TL ages of approximately 110 ± 16 ka BP. This sandy layer lies below a 6-m-thick, massive (non-laminated), clayey stratum. It is hypothesised that a large but short-lived lake formed during the interglacial phase separating the penultimate and last glaciations. Assigning a ‘Riss’ age to the southeastern part of the amphitheatre therefore regains credence. © 1998 John Wiley & Sons, Ltd.     

Surface texture analysis of southern Tuli Basin sediments: Implications for Limpopo Valley geoarchaeological contexts

The Hackthorne 1 site (southern Tuli Basin, South Africa) is situated on a sand-covered plateau adjacent to the Limpopo River Valley. Although the site is well known for its Stone Age archaeology, the past environmental contexts (particularly sedimentological/geomorphological) are not well known. We examine the Hackthorne sand grain surface textures, so as to provide some insight on the site specific and regional depositional history. Quartz sands at Hackthorne were collected from surface sands and from underlying weathered calcrete. SEM analysis was performed on sand grains, through which several mechanical and chemical microtextures were identified. Microtextures typical of fluvial environments were found only on grains derived from the plateau calcrete host sediment, whilst the surface sands exhibited only textures associated with aeolian environments. The results indicate that the calcrete host sediment is composed of alluvium, and that the surface sands mantling the Hackthorne Plateau are not deflated from the alluvial deposits in the Limpopo Valley, but may rather be derived from distant aeolian sources. The deposition of aeolian sands is consistent with OSL dates which place sand deposition, or remobilization, at 23 and 15 kya, periods in southern Africa associated with increased aridity.     

Thermoluminescence dating of St. Croix ceramics: Chronology building in Southwestern Nova Scotia

Using the classic thermoluminescence (TL) dating technique for fired ceramic materials, we have obtained the first direct ages for five ceramic artifacts recovered from BfDa-1, a prehistoric archaeological site located in St. Croix, southcentral Nova Scotia. BfDa-1 is the only archaeological site in Nova Scotia to produce the full range of ceramic styles associated with the Woodland or Ceramic Period (c. 1050 B.C. to A.D. 1500); thus our new chronology can be used to revise the current local and regional ceramic chronologies. The five sherds from the St. Croix site yielded absolute gas of 1.15 ± 0.15 ka to 2.62 ± 0.29 ka (1 ka = 1000 years). The oldest of these TL ages was obtained on a sherd decorated with a pseudoscallop shell design and is in excellent agreement with a ¹⁴C date of 2500 ± 120 B.P. associated with Early Ceramic artifacts at this site. The other TL ages are in agreement with the relative ceramic chronology deduced from their decorative attributes. All five TL dates are in the correct depth-age order. This demonstrates that the recent excavations explored a part of the site which remained undisturbed in spite of extensive agricultural and horticultural activities in the vicinity in recent centuries. The dates also indicate a high degree of compression for the cultural remains at the site. They suggest a sediment deposition rate of 1.3 cm/100 yr during the early stages of the occupation period (2000–2600 yr B.P.), and a decrease in the deposition rate to 0.5 cm/100 yr during the last 2000 years. These dates provide the first successful application of TL dating to ceramics of the Minas Basin area. They confirm an initial hypothesis based on the stylistic attributes of ceramics recovered from BfDa-1, that human occupation at the site must have been of long duration. The excellent quality of the analytical data indicates that the TL dating technique should be well suited to the study of ceramic technology in other parts of the province, and that local mineralogy is suitable for optical dating of sediments at the site and elsewhere in Nova Scotia. © 1997 John Wiley & Sons, Inc.     

Thermoluminescence dating of sediments

The potential for using the thermoluminescence behaviour of sediments for dating them was first recognized by Soviet scientists G.V. Morozov and V.N. Shelkoplyas, and for over a decade their TL dates, obtained from a variety of sediments, have appeared in the Soviet literature. Since 1977 TL sediment dates have been published by six additional groups using a variety of methods.In this review we describe the principles of TL dating, the various methods used, and contrast TL dating of sediments with the now well-accepted TL dating of pottery. We conclude that while TL dating has the potential to solve many sedimentary problems, more fundamental research needs to be carried out before such dates should be accepted. A set of criteria for acceptable dates is proposed.     

Thermoluminescence dating of pottery from Sringaverapura—A Ramayana site

The first thermoluminescence (TL) dates of pottery from aRamayana associated site are reported. The TL dates for pre-NBPW Black-Slipped Ware levels are 730 and 765 B.C., while radiocarbon date takes the earliest Black Slipped Ware level (for which no TL dates are available) to 905 B.C. (uncorrected). For the OCW level, three TL dates are available which range from 1035 B.C. to 875 B.C. The early NBPW period believed to be associated with theRamayana episode will thus be post-750 B.C.     

Simultaneous determination of alteration and eruption ages of volcanic rocks by electron spin resonance

The alteration and eruption ages of Japanese welded tuffs were estimated by the method of ESR using Ge, OHC and Al centers in quartz whose stabilities are different. The ages obtained from the Ge and OHC centers were 1–2 Ma, however the ages from the Al center varied from 0.059 to 1.36 Ma. The comparison of these ages with thermoluminescence (TL) and fission track (FT) ages proves that the ESR age of the Al center, which agrees with the TL age, shows the thermal history and, in an ideal case, gives the alteration age: those of the Ge and OHC centers, which agree with FT age, indicate the eruption age. Therefore, this method enables us to describe the thermal history of a rock.     

Sedimentology, stratigraphy and landscape evolution of a Holocene coastal dune system, Lodbjerg, NW Jutland, Denmark

The stratigraphy and landscape evolution of the Lodbjerg coastal dune system record the interplay of environmental and cultural changes since the Late Neolithic. The modern dunefield forms part of a 40 km long belt of dunes and aeolian sand‐plains that stretches along the west coast of Thy, NW Jutland. The dunefield, which is now stabilized, forms the upper part of a 15–30 m thick aeolian succession. The aeolian deposits drape a glacial landscape or Middle Holocene lake sediments. The aeolian deposits were studied in coastal cliff exposures and their large‐scale stratigraphy was examined by ground‐penetrating radar mapping. The contact between the aeolian and underlying sediments is a well‐developed peaty palaeosol, the top of which yields dates between 2300 BC and 600 BC . Four main aeolian units are distinguished, but there is some lateral stratigraphic variation in relation to underlying topography. The three lower aeolian units are separated by peaty palaeosols and primarily developed as 1–4 m thick sand‐plain deposits; these are interpreted as trailing edge deposits of parabolic dunes that moved inland episodically. Local occurrence of large‐scale cross‐stratification may record the head section of a migrating parabolic dune. The upper unit is dominated by large‐scale cross‐stratification of various types and records cliff‐top dune deposition. The nature of the aeolian succession indicates that the aeolian landscape was characterized by alternating phases of activity and stabilization. Most sand transported inland was apparently preserved. Combined evidence from luminescence dating of aeolian sand and radiocarbon dating of palaeosols indicates that phases of aeolian sand movement were initiated at about 2200 BC , 700 BC and AD 1100. Episodes of inland sand movement were apparently initiated during marked climate shifts towards cooler, wetter and more stormy conditions; these episodes are thought to record increased coastal erosion and strong‐wind reworking of beach and foredune sediments. The intensity, duration and areal importance of these sand‐drift events increased with time, probably reflecting the increasing anthropogenic pressure on the landscape. The formation of the cliff‐top dunes after AD 1800 records the modern retreat of the coastal cliffs.     

Holocene aeolian development in Central Spain; chronology,regional correlations and causal processes

Extensive areas in the southern part of the Duero Tertiary Basin (Central Spain) are covered by aeolian sands. Presently, the aeolian system is relict but in its origin and development it can be described as a “wet aeolian system”. Climatic and environmental changes during the Holocene are typified by alternating humid and arid periods. These are recorded in the sedimentary record as either organic-rich sandy palaeosols or clean aeolian sand, respectively. Palaeosol dating (12 radiocarbon dated samples) and stratigraphical and sedimentological analysis of several dunefields in quarries and boreholes allow the distinction of four periods of palaeosol development since the Allerød.Aeolian sediments commonly rest on fluvial deposits, which were themselves the major source area for aeolian sands. These fluvial deposits have an age of about 14,000 cal yr BP. The first phase of aeolian activity postdates these fluvial sediments and has an upper age of about 12,000–11,700 cal yr BP, probably corresponding to the last cold oscillation of the Lateglacial (Younger Dryas). The second phase ranges from about 11,500 to 9500 cal yr BP, during which period the majority of dunes in the Tierra de Pinares area formed. This is also a major phase of aeolian activity in other areas of the Iberian Peninsula. A third and probably discontinuous phase of aeolian activity took place between 6800 and about 3000 cal yr BP. The age for this phase is supported by the presence of Visigothic burial sites covered by aeolian sands. The presence of charred material and degraded slipfaces clearly indicate stabilisation by vegetation and the final degradation of the aeolian system at the end of the fourth aeolian phase (990–540 cal yr BP). Minor aeolian activity has also occurred subsequently in this area, since aeolian sand movement was even reported in the 20th century.The aeolian phases can be tentatively correlated with aeolian phases in Europe. Aeolian activity tends to occur regionally during specific time-intervals, especially in dunefields with little human disturbance. This argues for a broad climatic forcing in Holocene aeolian accumulation, such has been previously suggested for the little ice age. The precise timing of these phases, however, is not strictly coincident, probably due to the delayed responses of aeolian environments to climatic and subsequent vegetation change.     

Luminescence dating of sand–loess sequences and response of Mu Us and Otindag sand fields (north China) to climatic changes

The sand–loess transition zone in north China is sensitive to climate change, and is an ideal place to investigate past environmental changes. However, past climate change at millennial–centennial timescales in this region has not been well reconstructed because of limited numerical dating. Alternations of sandy loam soils with aeolian sand layers in the Mu Us and Otindag sand fields, which lie along the sand–loess transition zone, indicate multiple intervals of dune activity and stability. This change is probably a response to variations of the East Asian monsoon climate during the late Quaternary. The single aliquot regeneration (SAR) optically stimulated luminescence (OSL) dating protocol, which has been successfully applied to aeolian deposits worldwide, is applied to these two sand fields in this study. The OSL ages provide reliable constraints for reconstruction of past climate changes at suborbital timescale. Sections in both sand fields contain aeolian sand beds recording millennial‐scale episodes of dry climate and widespread dune activation, including episodes at about the same time as Heinrich Event 5 and the Younger Dryas in the North Atlantic region. These results demonstrate the potential of aeolian sediments in semi‐arid north China to record millennial‐scale climatic events, and also suggest that dry–wet climate variation at the desert margin in China may be linked to climatic change elsewhere in the Northern Hemisphere, through atmospheric circulation. This article was published online on 27 November 2008. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected (16 December 2008). Copyright © 2008 John Wiley & Sons, Ltd.     

Comparison of thermoluminescence and radiocarbon age-determinations from late-pleistocene alluvial deposits near Sydney, Australia

Radiocarbon and thermoluminescence (TL) age-determinations have been obtained for a large Pleistocene alluvial terrace on the Nepean River near Sydney, New South Wales, Australia. The deposit was laid down by a braided river system prior to the last glacial maximum. Six thoroughly pretreated samples of charcoal and degraded wood buried within gravels at the base of the terrace yielded apparent ¹⁴C ages of 37,000–42,000 yr B.P. These compare favorably with four TL determinations that gave apparent ages of 41,000–47,000 yr B.P. for the same deposit. Adjustment of the ¹⁴C ages to take geomagnetic effects into account further improves the correlation between these two independent dating techniques. In addition, ¹⁴C and TL correctly identified a reworked portion of the fine-grained alluvial overburden as being substantially younger than the main body of the terrace. These results augur well for the usefulness of TL age determinations of certain alluvial deposits.