Part Of Marine Isotope Stage Research Articles

Environmental and climatic inferences for Marine Isotope Stage 2 of southern Belgium (Meuse valley, Namur Province) based on rodent assemblages

The environmental and climatic conditions of the Late Pleistocene of Southern Belgium are here determined for the final part of Marine Isotope Stage 3 (MIS 3) and for MIS 2 on the basis of a study of rodent assemblages. This paper provides a synthesis of several sets of environmental and climatic data from Late Pleistocene sites, all of which are located in southern Belgium. One has previously been published (Caverne Marie-Jeanne), and seven are unpublished (Cavernes de Goyet, Trou des Nutons, Trou du Frontal, Trou de Chaleux, Grotte la Chefalize, Trou du Chêne, and Trou du Sureau). The habitat weighting and quantified ecology methods are applied to rodent material housed in the Royal Belgian Institute of Natural Sciences (RBINS, Brussels), and previous radiocarbon dates are updated, in order to reconstruct past environments. Among all the sites under analysis, the quantified ecology method shows that Trou de Chaleux corresponds to the coldest temperatures and lowest precipitation. Trou de Chaleux, with a chronology between ca. 15,964–14,014 cal yr B.P., could probably be placed in Greenland Stadial 2 (GS2) or Heinrich Event 1 (HE1). It has a rodent assemblage associated with a predominance of open dry and rocky formations, the most abundant species being the collared lemming and the narrow-headed vole. These data are found to coincide with previous studies carried out on the large-mammal, herpetofaunal, and avifaunal associations of the site, as well as on small-mammal associations from other sites in southern Belgium with similar chronology, such as Grotte Walou. Taken together, this indicates that these latest Pleistocene intervals in southern Belgium were characterized by harsh climatic and environmental conditions. In contrast, the other assemblages under study yielded much more heterogeneous results, frequently inconsistent with an attribution to the Pleistocene. This is likely to be a result of their admixture with Holocene material due to recent intrusions.

Comparison of High-Resolution 14C and Luminescence-Based Chronologies of the MIS 2 Madaras Loess/Paleosol Sequence, Hungary: Implications for Chronological Studies

Numerous loess/paleosol sequences (LPS) in the Carpathian Basin span the period of Marine Isotope Stage (MIS) 2 and the last glacial maximum (LGM). Nevertheless, only two known records—Madaras and Dunaszekcső—preserve highly resolved records with absolute chronologies with minimal uncertainties, which enable the meaningful assessment of feedbacks and short-term climatic fluctuations over this period. The Madaras profile is located at the northern margin fringe of the Bácska loess plateau; Dunaszekcső, located on the Danube to its west, yields a chronology built on over 100 14C dates yet spans only part of MIS 2, missing half of the LGM including its peak. Here, we add to the previously published 14C chronology for Madaras (15 dates) with an additional 17 14C and luminescence ages. Resulting age models built solely on quartz OSL and feldspar pIRIRSL data underestimate the 14C based chronology, which is likely based on inaccuracies related to luminescence signal behavior; we observe age underestimations associated with unusual quartz behavior and significant signal loss, a phenomenon also observed in Serbian and Romanian loess, which may relate to non-sensitized grains from proximal sources. Our new chronology provides higher resolution than hitherto possible, yielding consistent 2 sigma uncertainties of ~150–200 years throughout the entire sequence. Our study indicates that the addition of further dates may not increase the chronological precision significantly. Additionally, the new age model is suitable for tackling centennial-scale changes. The mean sedimentation rate based on our new age-depth model (10.78 ± 2.34 years/cm) is the highest yet recorded in the Carpathian Basin for MIS 2. The resolution of our age model is higher than that for the Greenland NGRIP ice core record. The referred horizons in our profile are all characterized by a drop in accumulation and a higher sand input, the latter most likely deriving from nearby re-exposed sand dunes.

Palaeoenvironmental changes and their chronology during the latter half of MIS 5 on the south-eastern coast of the Gulf of Finland

This paper presents an overview of the results obtained by collaborative use of integrative multidisciplinary investigation of a highly unique geological section discovered in the south-eastern part of the Gulf of Finland. The main aim of this study is to identify the Late Pleistocene palaeoenvironmental and palaeoclimatic changes in the study area during one of the most controversial periods in the Late Pleistocene history, which is the MIS 5. Our approach to achieving the goal is based on the investigation of feldspar-based infrared optically stimulated luminescence (IR-OSL) dated records of pollen-induced palaeoclimate and palaeoenvironmental proxies. Palynological analysis and IR-OSL dates of 29 samples for the first time produced a detailed, characterised and dated sequence of palynological zones M6 to M8 ranging from ca. 94 ka to ca. 70 ka and made it possible to determine the chronological sequence of climate changes in this interval. Representative pollen spectra from 69 samples provided convincing evidence of a warm interval of interglacial rank at least during the latter half of MIS 5. The data obtained in the present study from well-preserved deposits of the second half of MIS 5 provided a novel insight into the palaenvironmental conditions during this period. These results seem to contradict the widely held view according to which the last interglacial stage with the climate conditions similar or warmer than today corresponds to only a small part of marine isotope stage (MIS) 5 of the deep-sea stratigraphy, i.e. MISs 5e lasting ca. 11 ka, and the period from 100 ka to 80 ka is attributed to an Early Weichselian glaciation, which in Northern Eurasia reached its maximum at about 90 ka. However, the findings obtained during the present study are also convincingly confirmed by those of our previous long-term investigations of warm climate-related shell-bearing deposits of various origins from Northern Eurasia including climatically highly sensitive Eurasian Arctic palaeo-shelf area. These results indicated that the overwhelming majority of the warm climate-related dates (ca. 82%) is also concentrated in the latter half of MIS 5 in the time range between 110 ka and 70 ka.

The role of an ice-sheet, glacioisostatic movements and climate in the transformation of Middle Pleistocene depositional systems: a case study from the Reda site, northern Poland

ABSTRACT This study provides a new stratigraphic and palaeogeographic scheme for the time span between Marine Isotope Stages (MISs) 8 and 6. Based on detailed sedimentological and palynological studies, the roles of the Scandinavian Ice Sheet (SIS) advances and changing climate in the evolution of sedimentary environments is considered. At the Reda site, northern Poland, vertically stacked, 25 m thick glacigenic and fluvial successions were distinguished and divided into four depositional complexes. Two glacigenic units (R1 and R 2), representing two SIS advances in study area, are separated by two fluvial units (R2 and R3). The first SIS advance recorded at the Reda site took place at the end of MIS 8. Proglacial fluvial systems transported material along the ice margin towards the NW (R1 complex). Migration of the forebulge during deglaciation led to incision and opened the outflow towards the SW. During the younger part of MIS 7, the older fluvial unit (R2 complex) was deposited in a sand-bed braided fluvial system in boreal climate conditions. Local erosion and change in the sedimentation style into a meandering one under periglacial conditions took place (R3 complex). The progressive cooling of the climate towards the end of MIS 6 resulted in another SIS transgression and deposition of coarse-grained sediments (R4 complex) in the ice-marginal zone during deglaciation. SIS played a key role in the formation of R1 and R4 complexes. Glacial processes managed the reshaping the landscape through the erosion of older sediments and in the formation of accommodation space. Glacioisostatic movement controlled accommodation space, accumulation-erosion ratio, size of catchment and morphology of the valley.

The Idre marginal moraine – An anchorpoint for Middle and Late Weichselian ice sheet chronology

We here report the results of luminescence and cosmogenic exposure dating of the Idre marginal moraine, located in the southern Scandinavian Mountains. This particular moraine is targeted because it is morphologically distinct and marks the margin of a former ice sheet. The till in the moraine contains erratics that provide strong evidence of flow from an ice sheet centred over Norway. The area immediately outside the moraine margin is an older residual soil. Luminescence ages of three samples taken from a sand lense within the moraine indicate that it formed at around 55 ka, during the early warm part of Marine Isotope Stage (MIS) 3. Median exposure ages (10Be) of ten samples from boulders embedded in the surface till indicate that about 30 ka of ice-free time have elapsed since formation of the moraine. The difference between the age of the ridge and the duration of exposure provides a measure of the time of ice-cover in the ice sheet core area. Previous research indicates that final deglaciation of the site occurred at approximately 10 ka ago, which in combination with our results implies that the area around the Idre marginal moraine was ice free for ca. 20 ka, i.e. from around 55 ka to around 35 ka. Thereafter, the area was glaciated and the marginal moraine was covered by the Late Weichselian ice sheet for around 25 ka without experiencing any significant erosion or morphological destruction. While earlier studies have already pointed towards MIS 3 ice free conditions in northern and central Sweden, this study contributes a measurement-based duration estimate for the MIS 3 interstadial.

Central Iberia in the middle MIS 3. Paleoecological inferences during the period 34–40 cal kyr BP

The environmental conditions that existed during the period between 45 and 30 ka are of vital importance for addressing the transition between the Middle and Upper Paleolithic. It seems to be a hiatus of Paleolithic populations, a “no (hu)man’s land” in Central Iberia, coinciding with the mid part of Marine Isotope Stage (MIS) 3, between 42 and 28 cal kyr BP. This break in the archaeological record makes it difficult to address this period paleoecologically. Here we present a new cave site, Portalón del Tejadilla (Segovia), dated to a period roughly between ∼34.2 and 40.4 cal kyr BP in which cold-adapted faunas, such as woolly rhinoceros and giant deer, have been recovered in a hyena den site context. This site is located in Central Iberia, and more specifically, on the southern edge of the northern Plateau, an unexpected region for the presence of these faunas during the MIS 3. These new findings extend the geographical distribution of several species, including Coelodonta antiquitatis and Megaloceros giganteus. Furthermore, they document a climatic deterioration (colder and dryer) during the mid MIS 3 in Central Iberia in one of the coldest and driest episodes of the Late Pleistocene. Portalón del Tejadilla fills this temporal gap and provides valuable paleoecological information about the transition between the Middle to Upper Paleolithic.

Intermediate water circulation changes in the Florida Straits from a 35 ka record of Mg/Li-derived temperature and Cd/Ca-derived seawater cadmium

We generated a high-resolution ocean record of bottom water temperature and seawater Cd from 546 m in the Florida Straits. The record extends to ∼35,000 yr before present, including all of Marine Isotope Stages (MIS) 2 and part of MIS 3. Previously, seawater cadmium (Cdw) has been used as a proxy for the strength of the Atlantic Meridional Overturning Circulation (AMOC) during the last deglaciation. We now consider the temperature and oxygen isotopic composition of seawater reconstructed from the same core in order to provide a fuller picture of water mass properties and circulation at this location. During the Last Glacial Maximum (LGM), Cdw levels were generally low, and a novel Mg/Li-derived temperature record reveals persistently cold temperatures (∼3.6°C, two to three degrees colder than during the Holocene or Marine Isotope Stage 3). During the Younger Dryas and early Heinrich Stadial 1, Cdw was low and temperatures were elevated compared with periods of inferred stronger AMOC. By contrast, there is no indication of AMOC variability over Heinrich Stadials 2 and 3, consistent with previous studies that conclude the AMOC is less sensitive to freshwater forcing during glaciations than during the last deglaciation. While there is some inconsistency between proxies, Cdw increases over some MIS3 Dansgaard–Oeschger interstadials, providing qualified support for a strengthening in AMOC. This is similar to our previous finding that Cdw tracks AMOC variability during the deglaciation. This study highlights the distinct nature of water masses and circulation during the LGM, relative to the stadial (weak AMOC) periods of the deglaciation and Late MIS 3.

Pollen-based temperature and precipitation changes in the Ohrid Basin (western Balkans) between 160 and 70 ka

Abstract. Our study aims to reconstruct climate changes that occurred at Lake Ohrid (south-western Balkan Peninsula), the oldest extant lake in Europe, between 160 and 70 ka (covering part of marine isotope stage 6, MIS 6; all of MIS 5; and the beginning of MIS 4). A multi-method approach, including the “Modern Analog Technique” and the “Weighted Averaging Partial Least-Squares Regression”, is applied to the high-resolution pollen sequence of the DEEP site, collected from the central part of Lake Ohrid, to provide quantitative estimates of climate and bioclimate parameters. This allows us to document climatic change during the key periods of MIS 6 and MIS 5 in southern Europe, a region where accurate climate reconstructions are still lacking for this time interval. Our results for the penultimate glacial show cold and dry conditions, while the onset of the “last interglacial” is characterized by wet and warm conditions, with temperatures higher than today (by ca. 2 ∘C). The Eemian also shows the well-known climatic tri-partition in the Balkans, with an initial pre-temperate phase of abrupt warming (128–121 ka), a central temperate phase with decreasing temperatures associated with wet conditions (121–118 ka), followed by a post-temperate phase of progressive change towards cold and dry conditions (118–112 ka). After the Eemian, an alternation of four warm/wet periods with cold/dry ones, likely related to the succession of Greenland stadials and cold events known from the North Atlantic, occurred. The observed pattern is also consistent with hydrological and isotopic data from the central Mediterranean. The Lake Ohrid climate reconstruction shows greater similarity with climate patterns inferred from northern European pollen records than with southern European ones, which is probably due to its intermediate position and the mountainous setting. However, this hypothesis needs further testing as very few climate reconstructions are available for southern Europe for this key time period.

New discoveries of the Huangniliang site and cultural diversity in North China during early MIS 3

The Huangniliang site, located in the coastal province of Shandong, in North China, was excavated in 2013. Optically stimulated luminescence results show that the age of the deposits ranges from 59 to 54 ka, corresponding to the initial part of Marine Isotope Stage (MIS) 3. This study introduces the detailed analyses of the stone artefacts from the site, and provides a review of the major Paleolithic sites dated to early MIS 3 in North China. Analyses of the Huangniliang lithic assemblage show that the principal flaking technique was direct hard-hammer percussion, but core preparations and systematic percussion are also present. A series of assemblages in North China show a diversified scenario before the Late Paleolithic (LP). Dominated by the simple flake-core tradition, lithic industries in northern China dated to 35–60 ka occasionally include a Mousterian-like industry, a macroblade technology, Acheulian-type large cutting tools, systematic percussion and diversified toolkits. Lithic technological organization expressed by systematic percussion and incipient organization on the land-use expressed by the organized acquisition of raw materials during early MIS 3 are indicators of behavioral complexity.

Evidence for a humid interval at ∼56–44 ka in the Levant and its potential link to modern humans dispersal out of Africa

This study provides a detailed reconstruction of the paleoenvironmental conditions that prevailed during one of the periods of modern human migration out of Africa and their occupation of the Eastern Mediterranean-Levant during the Late Middle Paleolithic-Early Upper Paleolithic. Tracing the past vegetation and climate within the Eastern Mediterranean-Levant region is largely based on a south-eastern Mediterranean marine pollen record covering the last 90 kyr (core MD-9509). The various palynomorphs were linked to distinct vegetation zones that were correlated to the two climate systems affecting the study area: the low-latitude monsoon system and the North Atlantic-Mediterranean climate system. The bioprovince palynological markers show that during the period between ∼56 and 44 ka, which covers the early part of Marine Isotope Stage 3 (MIS 3), there was an increase in transportation of pollen from Nilotic origin and a rise in dinoflagellate cyst ratios. These changes coincided with maximum insolation values at 65°N, which led to an enhancement in Nile River discharge into the Eastern Mediterranean following the intensification of the African monsoonal system. At the same time, the rise in Mediterranean arboreal pollen values (broadleaved, coniferous and deciduous temperate trees) is most likely driven by increased precipitation related to the intensification of the North Atlantic-Mediterranean climate system. The ∼56–44 ka wet event coincides with Dansgaard-Oeschger interstadials 14 and 12 and with a warming phase in the Levant, as evidenced by the melting of permafrost along the higher elevations of Mount Hermon. We suggest that African modern humans were able to cross the harsher arid areas due to the intensification of the monsoonal system during the first part of MIS 3, and inhabit the Eastern Mediterranean-Levant region where climatic conditions were favorable (wetter and warmer), even in the currently semiarid/steppe regions.

Homo sapiens in Arabia by 85,000 years ago.

Understanding the timing and character of Homo sapiens expansion out of Africa is critical for inferring the colonisation and admixture processes that underpin global population history. It has been argued that dispersal out of Africa had an early phase, particularly ~130-90 thousand years ago (ka), that only reached the East Mediterranean Levant, and a later phase, ~60-50 ka, that extended across the diverse environments of Eurasia to Sahul. However, recent findings from East Asia and Sahul challenge this model. Here we show that H. sapiens was in the Arabian Peninsula before 85 ka. We describe the Al Wusta-1 (AW-1) intermediate phalanx from the site of Al Wusta in the Nefud Desert, Saudi Arabia. AW-1 is the oldest directly dated fossil of our species outside Africa and the Levant. The palaeoenvironmental context of Al Wusta demonstrates that H. sapiens using Middle Palaeolithic stone tools dispersed into Arabia during a phase of increased precipitation driven by orbital forcing, in association with a primarily African fauna. A Bayesian model incorporating independent chronometric age estimates indicates a chronology for Al Wusta of ~95-86 ka, which we correlate with a humid episode in the later part of Marine Isotope Stage 5 known from various regional records. Al Wusta shows that early dispersals were more spatially and temporally extensive than previously thought. Early H. sapiens dispersals out of Africa were not limited to winter rainfall-fed Levantine Mediterranean woodlands immediately adjacent to Africa, but extended deep into the semi-arid grasslands of Arabia, facilitated by periods of enhanced monsoonal rainfall.

New palaeoenvironmental and palaeoclimatic reconstructions for the Middle Palaeolithic site of Cuesta de la Bajada (Teruel, eastern Spain) inferred from the amphibian and squamate reptile assemblages

In the eastern Iberian Peninsula, the archaeological site of Cuesta de la Bajada (Teruel, Spain) has produced some of the earliest evidence of Middle Paleolithic stone tool traditions together with evidence of equid and cervid carcasses defleshed by hominins. Based on the numerical age of 317-240 ka derived from OSL, ESR and AAR dating methods for the lower part of the Cuesta de la Bajada sedimentological sequence (level CB3), as well as the biochronological inferences for the small and large mammal associations, the site can be attributed to Marine Isotope Stage (MIS) 8 or the end of MIS 9. As amphibians and reptiles have precise environmental and climatic requirements and do not differ at species level from the extant herpetofauna of the Iberian Peninsula, they can contribute to the reconstruction of the landscape and climate. In this paper, the fossil amphibians and squamate reptiles from Cuesta de la Bajada are studied for the first time. The mutual ecogeographic range and habitat weighting methods were applied to the herpetofaunal assemblages to estimate quantitative data for the landscape and climate reconstructions. The climate is shown to have been colder and wetter than today in the interior of eastern Spain, with mean annual temperature up to 2.5 °C lower and mean annual precipitation slightly higher than at present. The monthly climatic reconstruction shows differences in the distribution of precipitation over the course of the year, with more abundant precipitation from late autumn to spring (i.e. from October to May), and more or less similar precipitation to today during the summer months (July and August). This suggests there was stronger rainfall seasonality between winter and summer than currently occurs. The paleoenvironmental reconstruction based on the herpetofaunal assemblage depicts a poorly forested (15–20%) patchy landscape with a large representation of dry meadows and scrubland habitats together with well-evidenced aquatic habitats. These reconstructions are consistent with other proxies recovered at Cuesta de la Bajada (pollen, small and large mammals) as well as other European MIS 8–9 paleoclimatic records. We can thus correlate levels CB2 and CB3 with the later part of MIS 8 (265-257 ka) or with a humid fluctuation within the MIS9b (303-290 ka). It is also possible to provide a new description of the environmental and climatic conditions that occurred in inner Spain during a cold period of the late Middle Pleistocene.

Late Quaternary vegetation and climate reconstruction based on pollen data from southeastern Inner Mongolia, China

A late Quaternary pollen record from the Liujiadian section (42°58′58.0″N, 117°26′39.3″E) situated in southeastern Inner Mongolia, spanning the last ca. 35ka, was used to reconstruct regional vegetation history and climate change. Three stages of vegetation dynamics and climate change are documented in this record. During 35.23 to 25.15ka, the latter part of Marine Isotope Stage (MIS) 3, a forest-steppe landscape developed under wet conditions dominated the surrounding areas. The following period, 25.15–11.13ka, approximately corresponding to MIS 2, was characterized by the overall drought conditions superimposing climatic oscillations. During 25.15–22.25ka, the shift to typical steppe highlighted the drought trend. After 22.25ka, severe drought conditions led to the invasion of desert-steppe. The modest climatic amelioration, occurred from 18.47 to 16.24ka, was characterized by the relieving drought, indicated by the replacement of typical steppe. The landscape was defined by the desert-steppe under a dry climate after 16.24ka and briefly interrupted by the recovering of typical steppe at the end of this interval. The Holocene likely commenced at about 11.13ka, reflected by the gradual establishing of forest-steppe in a relatively humid climate. Regional comparisons suggest a roughly synchronous pattern of climate change and variations in the East Asian summer monsoon (EASM), attributing to the force of the northern hemisphere summer insolation and ice volume. In addition, the millennial-scale EASM variability has coincided with the Heinrich (H) and Dansgaard–Oeschger (D–O) events, and the Younger Dryas (YD), indicating the plausible linkage to the rapid Atlantic meridional overturning circulation (AMOC) oscillations.

Very Large Cryoturbation Structures of Last Permafrost Maximum Age at the Foot of Qilian Mountains (NE Tibet Plateau, China): a Discussion

AbstractIntensely cold conditions occurred during part of the last major glaciation of the mountains and Qinghai–Tibet Plateau in northeast China but their chronology is constrained by few limiting ages. At the Mengyuan section, on the northeastern margin of the Qilian Mountains, sandy silt provided three OSL ages that suggest deposition during a very cold, dry period in northeastern China between c. 29 and 19 ka (early part of marine isotope stage (MIS) 2). Load‐casting into the underlying outwash gravel occurred during climate amelioration. In some cases, the sandy silt infilled the spaces left by underlying thawing blocks of ice without collapse of the surrounding gravel. The gravel must therefore be older than c. 30 ka and was probably deposited by outwash from glaciers on the higher parts of the Qilian Mountains during MIS 3. Included in them were buried contemporaneous or remnant blocks of glacial ice. Subsequently the surface became flat by unknown processes and was finally covered by a thin loess dating from 2.7 ka, indicating it was deposited in the first warmer period in the Neoglacial sequence of events. Thus, the last major cold event spanned the period through isotope stages 2 and 3 in this area (57 to c. 19 ka), during which the dominant effects of glaciation of the mountain tops were replaced by intensely dry, cold permafrost conditions for c. 10 ka. Copyright © 2017 John Wiley & Sons, Ltd.

Human occupation of the northern Arabian interior during early Marine Isotope Stage 3

ABSTRACTThe early part of Marine Isotope Stage (MIS) 3 (ca. 60–50 ka) is a crucial period for studying human demography and behaviour in south‐west Asia, and how these relate to climatic changes. However, the archaeological and palaeoenvironmental records for MIS 3 in critical areas such as the Arabian Peninsula remain poorly developed. Here, we present findings from the Al Marrat basin in the Nefud desert, which provides the first clear evidence for both increased humidity and human occupation of the interior of northern Arabia during early MIS 3. A Middle Palaeolithic assemblage, dated by optically stimulated luminescence to ca. 55 ka, was found stratified within a sequence of relict palustrine deposits indicative of shallow water body formation in the Al Marrat basin. Hominin presence in northern Arabia at this time coincides with the intensification and northward displacement of monsoon rainfall systems during a period of maximum insolation. These findings add to a growing corpus of palaeoenvironmental evidence, which indicates that the Arabian interior was neither arid nor unpopulated during early MIS 3, and that hydrodynamic responses to enhanced moisture availability facilitated demographic expansions into the Arabian interior.

Episodic speleothem deposition tracks the terrestrial impact of millennial-scale last glacial climate variability in SW Ireland

Abstract Eighty four new U-Th ages are presented for twenty randomly selected broken, displaced and reworked calcite speleothems retrieved from clastic sedimentary fill and from isolated bedding-plane shelves in Crag cave (SW Ireland). The dated pre-Holocene samples span much of the last glacial, ranging in age from 85.15 ± 0.60 to 23.45 ± 0.17 ka. Speleothem deposition requires the presence of liquid water, and because Crag cave is a shallow system, deposition is considered likely only when mean annual air temperatures (MAAT) exceed the freezing point of water. Deposition at this mid-latitude ocean-marginal site occurred episodically during MIS5a through to MIS2, synchronously within dating uncertainties, with the timing of Greenland Interstadials (GI). In the latter part of Marine Isotope Stage 3 (MIS3), deposition was particularly intense, consistent with regional scale climate amelioration inferred previously from radiocarbon ages for sparse MIS3 organic and freshwater surficial deposits in N. Ireland. A brief episode of speleothem deposition at c.23.40 ± 0.22 ka coincides with GI-2, demonstrating the sensitivity of the site to brief climate amelioration episodes in Greenland during MIS2. Conditions favourable for speleothem deposition occurred periodically during the last glacial, indicating temperature changes of at least 10 °C between stadials and interstadials at this mid-latitude site. Deposition ceased during Greenland Stadials (GS), including during periods of ice-rafting in the adjacent N. Atlantic Ocean (Heinrich events). Oxygen and carbon isotope ratios of the last glacial speleothems are generally elevated, reflecting non-equilibrium isotope fractionation effects. However, establishment of low δ13C values often occurred within a few decades of climate amelioration, indicating that biogenic CO2 production resumed rapidly at this site, particularly during MIS3. Speleothem δ18O variability was driven largely by long-term changes in the δ18O value of the adjacent North Atlantic surface water, in turn largely reflecting changes in global ice volume. In common with published speleothem datasets, warming episodes in Ireland associated with GI events typically pre-date their timing in the GICC05 and GICC05modelext time scales, but lie comfortably within the maximum counting uncertainties of these ice core age models.

UK′37 temperature estimates from Eemian marine sediments in the southern coast of Hainan Island, tropical China

This study concerns high-resolution sea surface temperature (SST) changes for the Eemian interglacial period reconstructed from the southern coast of Hainan Island, China. The lower marine unit in the sediment core is composed of monotonous mud (31m thick), dated to be from the Eemian interglacial period or lower part of marine isotope stage 5 (MIS 5), determined by optically stimulated luminescence (OSL). The high sedimentation rate and the richness of organic matter and marine fossils provide good opportunity for the study of palaeo-environments in the northern margin of the South China Sea (SCS). Sediment grain-size, foraminifer, sediment color index and long-chain alkenone were used to reveal the near-shore sedimentary environments and temperature at millennial-scale. Specifically, a high-resolution UK′37-SST record was reconstructed for the Eemian interglacial period. The new evidence in northwestern margin of SCS shows that the maximum value of SST during the Eemian interglacial is approximately 29°C and the lowest is 26.5°C. The trend of decreasing SST from 29°C throughout the marine sequence is consistent with the variations in sediment grain size, reflecting the cooling trend of SST and sea-level lowering tendency during the last interglacial period. This new Eemian SST result agrees with other records in the region of SCS, showing a coherent descending trend, but spatial heterogeneity exists in timing and amplitude. The insolation changes might be the main force for initiating the SST evolution during the penultimate interglacial period.

The Korean early Late Paleolithic revisited: a view from Galsanri

The Early to Late Paleolithic transition in eastern Asia is a topic receiving increasing attention in paleoanthropology. Here, we present the findings from Galsanri, an early Late Paleolithic open-air site that dates to the latter part of marine isotope stage 3 in South Korea. Findings from Galsanri suggest the Early to Late Paleolithic behavioral transition was unlikely to have been the result of a simple mass dispersal event from western Eurasia into eastern Asia. The Galsanri lithic assemblage includes typical Early Paleolithic core and flake tools in the same context as Late Paleolithic blades produced on low-quality raw materials and ground stone tools. The implications of the Galsanri findings are discussed in their broader behavioral contexts.

Age of Mammuthus trogontherii from Kostolac, Serbia, and the entry of megaherbivores into Europe during the Late Matuyama climate revolution

At the Drmno open-pit coal mine near Kostolac in Serbia, a nearly complete skeleton of Mammuthus trogontherii (nicknamed Vika) was discovered in a fluvial deposit overlain by a loess–paleosol sequence where a second paleontological level named Nosak with remains of M. trogontherii was found. We studied the magnetostratigraphy of the Kostolac sedimentary sequence and found that the Vika layer dates to ~0.8Ma, shortly before the Brunhes–Matuyama boundary. In addition, according to our age model and previously reported optically stimulated luminescence and electron spin resonance dates, the Nosak fossils have an estimated age of 0.19Ma and lived during the earliest part of Marine Isotope Stage 6. It appears therefore that at Kostolac, M. trogontherii is preserved both at its earliest occurrence at ~0.8Ma and close to its latest occurrence at 0.19Ma, and may well have been present in between, albeit not yet found. We speculate that megaherbivores such as M. trogontherii entered Europe along a conjunct Danube–Po River migration conduit connecting western Asia-Levant with central-southern Europe where vast and exploitable ecosystems, particularly suited for steppe- or savanna-adapted megaherbivores from Asia and Africa, developed during the late early Pleistocene climate revolution at around 0.8Ma.

MIS 3 to MIS 1 temporal and LGM spatial variability in Arctic Ocean sea ice cover: Reconstruction from biomarkers

AbstractUsing the sea ice proxy IP25 and phytoplankton‐derived biomarkers (brassicasterol and dinosterol), Arctic sea ice conditions were reconstructed for Marine Isotope Stage (MIS) 3 to 1—with special emphasis on the Last Glacial Maximum (LGM)—in sediment cores from the northern Barents Sea continental margin across the central Arctic Ocean to the southern Mendeleev Ridge. Our results suggest more extensive sea ice cover than present day during the latter part of MIS 3, increasing sea ice growth during MIS 2 and decreased sea ice cover during the last deglacial. The summer ice edge remained north of the Barents Sea even during extremely cold (i.e., Last Glacial Maximum (LGM)) as well as warm periods (i.e., Bølling‐Allerød). During the LGM, the western Svalbard margin and the northern Barents Sea margin areas were characterized by high concentrations of both IP25 and phytoplankton biomarkers, interpreted as a productive ice edge situation caused by the inflow of warm Atlantic water. In contrast, the LGM central Arctic Ocean (north of 84°N) was covered by thick permanent sea ice throughout the year with rare breakup, indicated by zero or near‐zero biomarker concentrations. The spring/summer sea ice margin significantly extended southward to the Laptev Sea shelf (southern Lomonosov Ridge) and southern Mendeleev Ridge during the LGM. Our proxy reconstructions are very consistent with published model results based on the North Atlantic/Arctic Ocean Sea Ice Model.