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Recent technological advancements in spectral imaging core-scanning techniques have proved to be a promising tool to study lake sediments at extremely high resolution. We used this novel analytical approach to scan core AU3 of the Pleistocene Auel maar, Western Germany. The resulting ultra-high-resolution RABD670 spectral index, a proxy for the lake's primary production, shows an almost complete succession of Greenland Interstadials of the NGRIP ice core chronology back to around 60,000 years. Using the ELSA-20 chronology and its anchor points to the NGRIP record as a stratigraphic basis, we were able to compare and fine-tune prominent climate signals occurring in both regions. This in-depth correlation yields strong evidence that the climates of Greenland and Central Europe were not only strongly coupled on timescales of stadials and interstadials but even on multidecadal scales, showing prominent climate cycles between 20 and 125 years. As climate changes in these regions were ultimately driven by variations in the North Atlantic meridional heat transport, their strong coupling becomes most apparent during cold and arid intervals. In contrast, longer-lasting warmer and more humid phases caused the activation of various regional feedback mechanisms (e.g., soil formation, forest growth), resulting in more complex patterns in the proxy records. [ABSTRACT FROM AUTHOR] more...

The regional impact of abrupt glacial climate variability remains poorly constrained for arid southwestern Asia, particularly winter dynamics during Marine Isotope Stage 3, due to limited paleoarchives in the Middle East. Here, we present continuous speleothem records of δ18O and δ13C with robust chronologies for southwestern and central Iran, spanning ∼50–30 ka. Stable‐isotope signals in the two stalagmites are generally uncorrelated and do not exhibit a consistent response to Greenland stadials or interstadials; however, both show a positive δ18O excursion that coincides with Heinrich event 4. We explore the potential mechanisms for intermittent coupling of speleothem δ18O across Iran through isotope‐enabled atmospheric modeling outputs, from which we utilize the spatial δ18O gradient as a proxy for wintertime westerly versus southerly jet strength. Our results suggest that during Heinrich event 4 and several Greenland stadials, stronger westerly winds enhanced Mediterranean moisture contributions to both sites and reduced aridity in southern Iran. Plain Language Summary: Stalagmites are useful archives to reconstruct the climate of the past. In order to shed light on the past climate of western Asia and the response of this region to the rapid climate changes, here we present two stalagmites from central and southwestern Iran that span 50,000 to 30,000 yrs ago. Our findings suggest that during extreme cold events, the moisture originates mostly from the west, whereas out of these extraordinarily cold periods moisture comes mostly from the south. Key Points: Continuous high‐resolution speleothem record of climatic change in southwestern and central Iran between 50 and 30 kaDecoupled responses of stable‐isotope gradients in central and southern Iran to glacial climate variability, except during Heinrich event 4Decreased impact of southerly moisture sources and reinforced westerlies during extreme cold events [ABSTRACT FROM AUTHOR] more...

Archaeological deposits from Waterfall Bluff Rock Shelter (Eastern Cape) span from Marine Isotope Stage 3 (~39–29 ka) to the mid-Holocene (~8 ka), showing persistent human occupations. The site’s consistent proximity to the shoreline and stable coastline over millennia makes it key for exploring human settlement patterns. This study reports on preliminary results of identifiable fauna from Marine Isotope Stage 3 to the Early Holocene layers at Waterfall Bluff. The identified species may suggest a mosaic environment, although caution is warranted given the small sample size. Furthermore, leopard seal remains were recovered in layers dating to the Last Glacial Maximum. This is the first direct evidence of a leopard seal recovered from Pleistocene and Holocene archaeo-faunal assemblages along the South African coast. Significance: Last Glacial Maximum (LGM) sites are rare in southern Africa. Waterfall Bluff in the Eastern Cape shows that human occupation persisted there from Marine Isotope Stage 3 to the mid-Holocene. A leopard seal tooth was identified in the LGM layers, making it the first evidence of this species recovered off South Africa’s coast. more...

We analyzed mineralogical characteristics, and major as well as rare earth element concentrations, from a cryptotephra layer in sediments of the infilled maar of Auel (Eifel, Germany). The results of detailed geochemical analyses of clinopyroxenes and their glassy rims from the Auel cryptotephra layer showed that they are similar to those from the thick Campanian Ignimbrite tephra occurrence in a loess section at Urluia (Romania). Both tephras show idiomorphic green clinopyroxenes and formation of distorted grains up to millimeter scale. The cryptotephra in the Auel core has a modelled age of around 39,940 yr b2k in the ELSA-20 chronology, almost identical to the latest 40Ar/39Ar dates for the Campanian Ignimbrite/Y-5 (CI/Y-5) eruption. These observations suggest that parts of the CI/Y-5 ash cloud were transported also northwestward into Central Europe, whereas the main branch of the CI/Y-5 ash plume was transported from southern Italy towards the NE, E, and SE. Based on pollen analyses, we conclude there was no direct effect on vegetation from the CI/Y-5 fallout in the Eifel area. Trees, shrubs, and grasses remained at pre-tephra-airfall levels for roughly 240 years, but changed around 39,700 yr b2k when thermophilic woody plants (e.g., Alnus and Carpinus) disappeared and Artemisia spread. This change in vegetation was well after the Laschamp geomagnetic excursion and also after the GI9 interstadial and quite probably represents the onset of the Heinrich Event 4 (H4) cold spell, when climatic conditions over the North Atlantic, and apparently also in Central Europe, deteriorated sharply. [ABSTRACT FROM AUTHOR] more...

Marine Isotope Stages (MIS) 4 and 3 were significant periods encompassing some 50,000 years, including at least two techno-cultural entities: the Howiesons Poort (HP) and post-HP. Exploring subsistence and environmental changes during these periods may help us understand broader aspects of behavioural and occupational patterns over MIS 4 and 3. In this paper, we report on taphonomic analyses of a sample of early HP, late HP and post-HP fauna from Klasies River main site cave 1A. We use these and other faunal data to examine the links between subsistence behaviour and the environment during the HP and post-HP. The results of our analyses indicate that percussion marks are abundant in the HP, with percussion mark frequencies more prevalent in the later HP than the early HP indicating that humans were the primary accumulators of fauna in the HP. Other taphonomic data such as fracture patterns, burning and trampling marks also suggests that human activity was more prevalent in the HP than the post-HP. In contrast, in the post-HP, the prevalence of zoogenic marks on small mammal remains, and comparisons to actualistic assemblages indicate that carnivores probably contributed significantly to the post-HP assemblage. In all the samples investigated, crania dominate skeletal-part profiles. This could be a result of taphonomic bias, or it could indicate that foraging likely occurred relatively close to the site. Analyses of carcass-part utility show that marrow-extraction may have been a key subsistence strategy in the HP. In the post-HP, bone density-mediated attrition had a significant effect on fauna making it challenging to ascertain subsistence patterns, but preliminary analysis may also suggest marrow extraction in combination with other strategies.Post-depositional taphonomic marks such as manganese staining suggest that post-HP and late HP deposits were significantly more affected by moisture than the early HP deposits. Previous investigations of large mammal data point to more closed environments in the early HP, while our data indicate that the environment in the late HP and post-HP was largely similar. In comparing our data to previously analysed micromammal proxy data, we show that major environmental changes at KRM occurred after the shift to post-HP lithic technology. However, the taphonomic data suggests a close relationship between changing subsistence strategies and the MIS4/3 transition. more...

Recent technological advancements in spectral imaging core-scanning techniques have proved to be a promising tool to study lake sediments at extremely high resolution. We used this novel analytical approach to scan core AU3 of the Pleistocene Auel maar, Western Germany. The resulting ultra-high-resolution RABD670 spectral index, a proxy for the lake’s primary production, shows an almost complete succession of Greenland Interstadials of the NGRIP ice core chronology back to around 60,000 years. Using the ELSA-20 chronology and its anchor points to the NGRIP record as a stratigraphic basis, we were able to compare and fine-tune prominent climate signals occurring in both regions. This in-depth correlation yields strong evidence that the climates of Greenland and Central Europe were not only strongly coupled on timescales of stadials and interstadials but even on multidecadal scales, showing prominent climate cycles between 20 and 125 years. As climate changes in these regions were ultimately driven by variations in the North Atlantic meridional heat transport, their strong coupling becomes most apparent during cold and arid intervals. In contrast, longer-lasting warmer and more humid phases caused the activation of various regional feedback mechanisms (e.g., soil formation, forest growth), resulting in more complex patterns in the proxy records. more...

We present a record of pollen and spores of coprophilous fungi from a sediment core from Auel infilled maar, Eifel, Germany, covering the period from 42,000 to 36,000 yr b2k. We can show that vegetation cover was dominated by a boreal forest with components of steppe and cold-temperate wood taxa. The proportion of wood taxa was higher during interstadials, whereas steppe-vegetation became more prominent during stadials. During Heinrich stadial 4, temperate taxa are mostly absent. Spores of coprophilous fungi show that megaherbivores were continuously present, albeit in a larger number during stadials when steppe environment with abundant steppe herbs expanded. With the onset of Greenland stadial 9, forests became more open, allowing for steppe-environment to evolve. The shift in vegetation cover coincides with the highest values of herbivore biomass at the time that Neanderthal humans demised and Anatomically Modern Humans most probably arrived in Central and Western Europe. Megaherbivore biomass was a direct consequence of vegetation cover/availability of food resources and thus an indirect consequence of a changing climate. Herds of large herbivores following suitable (steppe) habitats may have been one cause of the migration of AMH into Europe, going along with their prey to productive hunting grounds. [ABSTRACT FROM AUTHOR] more...

Regions located on the Chinese Loess Plateau are sensitive to changes in the Asian monsoon because they are on the edge of the monsoon region. Based on six 230Th experiments and 109 sets of stable isotope data of LH36 from Lianhua Cave, Yangquan City, Shanxi Province, we obtained a paleoclimate record with an average resolution of 120 years from 54.5 to 41.1 ka BP during the MIS3 on the Chinese Loess Plateau. Both the Hendy test and the replication test indicated an equilibrium fractionation of stable isotopes during the stalagmite deposition. Comparison with four other independently-dated, high-resolution stalagmite δ13C records between 29°N and 41°N in the Asian monsoon region shows that the stalagmite δ13C records from different caves have good reproducibility during the overlapped growth period. We suggest that speleothem δ13C effectively indicates soil CO2 production in the overlying area of the cave, reflecting changes in the cave's external environment and in the Asian summer monsoon. Five millennial-scale Asian summer monsoon intensification events correspond to the Dansgaard–Oeschger 10–14 cycles recorded in the Greenland ice core within dating errors, and the weak monsoon processes are closely related to stadials in the North Atlantic. The spatial consistency of stalagmite δ13C records in China suggests that the Asian summer monsoon and the related regional ecological environment fluctuations sensitively respond to climate changes at northern high latitudes through sea-air coupling on the millennial timescale. [ABSTRACT FROM AUTHOR] more...

We analyzed mineralogical characteristics, and major as well as rare earth element concentrations, from a cryptotephra layer in sediments of the infilled maar of Auel (Eifel, Germany). The results of detailed geochemical analyses of clinopyroxenes and their glassy rims from the Auel cryptotephra layer showed that they are similar to those from the thick Campanian Ignimbrite tephra occurrence in a loess section at Urluia (Romania). Both tephras show idiomorphic green clinopyroxenes and formation of distorted grains up to millimeter scale. The cryptotephra in the Auel core has a modelled age of around 39,940 yr b2k in the ELSA-20 chronology, almost identical to the latest 40Ar/39Ar dates for the Campanian Ignimbrite/Y-5 (CI/Y-5) eruption. These observations suggest that parts of the CI/Y-5 ash cloud were transported also northwestward into Central Europe, whereas the main branch of the CI/Y-5 ash plume was transported from southern Italy towards the NE, E, and SE. Based on pollen analyses, we conclude there was no direct effect on vegetation from the CI/Y-5 fallout in the Eifel area. Trees, shrubs, and grasses remained at pre-tephra-airfall levels for roughly 240 years, but changed around 39,700 yr b2k when thermophilic woody plants (e.g., Alnus and Carpinus) disappeared and Artemisia spread. This change in vegetation was well after the Laschamp geomagnetic excursion and also after the GI9 interstadial and quite probably represents the onset of the Heinrich Event 4 (H4) cold spell, when climatic conditions over the North Atlantic, and apparently also in Central Europe, deteriorated sharply. more...

The acquisition of large prey by hominins living during the Marine Isotope Stage 3, including Neanderthals and Anatomically Modern Humans, had nutritional and bioenergetic implications: these contain high fat amounts, provide a high energy return, and the strategies and skills required to acquire small prey were different from those required to acquire the former. Vitamin C availability at several MIS 3 periods could have had a strong seasonal variability and would have been decisive for hominin groups' survival. During the cold periods of the MIS 3, Paleolithic hominins had variable available amounts of vitamin C-containing plants only in the short summers, and for the remainder of the year, viscera would have been their best source of vitamin C. Meanwhile, the dependence on small mammals could have caused an erratic distribution of viscera to be consumed by such hominins, thus leading to chronic scurvy, and compromising their survival. Then, the hunting of large mammals would have helped to meet the daily vitamin C needs, besides an efficient energy supply. Therefore, the decline of large prey during the MIS 3 could have been critical for hominins survival, and thus the efficient exploitation of alternative vitamin C-rich food resources such as birds and aquatic animals could have favored the evolutionary success of hominin populations. [ABSTRACT FROM AUTHOR] more...

We present a record of pollen and spores of coprophilous fungi from a sediment core from Auel infilled maar, Eifel, Germany, covering the period from 42,000 to 36,000 yr b2k. We can show that vegetation cover was dominated by a boreal forest with components of steppe and cold-temperate wood taxa. The proportion of wood taxa was higher during interstadials, whereas steppe-vegetation became more prominent during stadials. During Heinrich stadial 4, temperate taxa are mostly absent. Spores of coprophilous fungi show that megaherbivores were continuously present, albeit in a larger number during stadials when steppe environment with abundant steppe herbs expanded. With the onset of Greenland stadial 9, forests became more open, allowing for steppe-environment to evolve. The shift in vegetation cover coincides with the highest values of herbivore biomass at the time that Neanderthal humans demised and Anatomically Modern Humans most probably arrived in Central and Western Europe. Megaherbivore biomass was a direct consequence of vegetation cover/availability of food resources and thus an indirect consequence of a changing climate. Herds of large herbivores following suitable (steppe) habitats may have been one cause of the migration of AMH into Europe, going along with their prey to productive hunting grounds. more...

Several millennial-scale warm phases perturbed the glacial climate during Marine Isotope Stage 3 (MIS 3, ca. 57–29 ka BP). Little is known about the impact of these climatic changes on Alpine ecosystems due to the sparsity of undisturbed sediment records in the Alps and their foreland. In this study, multiple sediment-archived proxies (sediment geochemistry, stable oxygen and carbon isotopes of autochthonous carbonate, and subfossil remains of macrophytes and aquatic invertebrates) were examined in five drill cores from an ancient inner-Alpine lake at Unterangerberg (Eastern Alps) to reconstruct the palaeolake environment and to estimate summer temperature changes for the first half of MIS 3. The lacustrine sedimentation in the basin began ca. 54.6 ka, tentatively correlated with the start of Greenland Interstadial (GI) 14. We identified three distinct phases in the development of the lake. (1) A cold, oligotrophic water body influenced by snow/glacier meltwater ca. 54.6–52.2 cal ka BP. (2) A clear-water, macrophyte-dominated, productive lake ca. 52.2–44.9 cal ka BP. Submerged macrophytes were dominated by the charophyte alga Chara hispida and chironomid assemblages – by Corynocera ambigua, which is absent from the present-day fauna of the Alpine region. (3) A turbid-water, less productive lake ca. 44.9–41.5 cal ka BP. This shift towards a turbid-water state, as evidenced by the drastic reduction in the abundance of submerged macrophytes and associated invertebrates, likely occurred due to increased input of meltwater. The regime shift is tentatively correlated with the start of GI 11, for which the highest temperatures of the studied MIS 3 interval are inferred. Chironomid-based reconstructions of mean July air temperatures provide interstadial temperature estimates between ca. 11 and 12.5°C (i.e. ca. 5–6°C below present-day values), which concurs with reconstructions available from the northern Alpine foreland. Cooler July temperatures (ca. 9–10°C) are reconstructed for MIS 3 stadials. The Unterangerberg lacustrine records provide valuable new insights into MIS 3 climate dynamics inside the Eastern Alps and contribute to a better understanding of the effects of climate change on the Alpine environment. more...

The acquisition of large prey by hominins living during the Marine Isotope Stage 3, including Neanderthals and Anatomically Modern Humans, had nutritional and bioenergetic implications: these contain high fat amounts, provide a high energy return, and the strategies and skills required to acquire small prey were different from those required to acquire the former. Vitamin C availability at several MIS 3 periods could have had a strong seasonal variability and would have been decisive for hominin groups’ survival. During the cold periods of the MIS 3, Paleolithic hominins had variable available amounts of vitamin C-containing plants only in the short summers, and for the remainder of the year, viscera would have been their best source of vitamin C. Meanwhile, the dependence on small mammals could have caused an erratic distribution of viscera to be consumed by such hominins, thus leading to chronic scurvy, and compromising their survival. Then, the hunting of large mammals would have helped to meet the daily vitamin C needs, besides an efficient energy supply. Therefore, the decline of large prey during the MIS 3 could have been critical for hominins survival, and thus the efficient exploitation of alternative vitamin C-rich food resources such as birds and aquatic animals could have favored the evolutionary success of hominin populations. more...

Abstract The climate of the western Mediterranean was characterized by a strong precipitation gradient during the Holocene driven by atmospheric circulation patterns. The scarcity of terrestrial paleoclimate archives has precluded exploring this hydroclimate pattern during Marine Isotope Stages 5 to 3. Here we present stable carbon and oxygen isotope records from three flowstones from southeast Iberia, which show that Dansgaard/Oeschger events were associated with more humid conditions. This is in agreement with other records from the Iberian Peninsula, the Mediterranean, and western Europe, which all responded in a similar way to millennial‐scale climate variability in Greenland. This general increase in precipitation during Dansgaard/Oeschger events cannot be explained by any present‐day or Holocene winter atmospheric circulation pattern. Instead, we suggest that changes in sea surface temperature played a dominant role in determining precipitation amounts in the western Mediterranean. more...

We present a mechanism for self‐sustained ocean circulation changes that cause abrupt temperature changes over Greenland in a multimillennial climate model simulation with glacial CO2 concentrations representative of Marine Isotope Stage 3. The Atlantic meridional overturning circulation (AMOC) and the subpolar gyre (SPG) oscillate on millennial time scales. When the AMOC is strong, the SPG is weak and contracted; when the AMOC is weak, the SPG is strong and extensive. The coupling between the two systems via wind‐driven and density‐driven feedbacks is key to maintaining the oscillations. The SPG controls the transport of heat and salt into the deep‐water formation sites and thus controls the AMOC strength. The strength and location of the deep‐water formation affect the density‐driven part of the SPG and thus control the mean strength and extent of the SPG. This mechanism supports the hypothesis that coupled ocean‐ice‐atmosphere interactions could have triggered abrupt glacial climate change. Plain Language Summary: Between 57.000 and 29.000 years ago, the last glacial period was marked by several abrupt warming and cooling events over Greenland and the North Atlantic. Understanding the mechanism behind these so‐called Dansgaard‐Oeschger events increases our understanding of possible tipping points that cause abrupt change in the Earth system. The role of the ocean in causing these events is still a topic of debate. We find abrupt changes in the North Atlantic circulation that resemble Dansgaard‐Oeschger events in a simulation with a state‐of‐the‐art climate model. These simulated ocean circulation changes are generated without adding external triggers such as meltwater from glaciers. Instead, the events are generated by the interaction of the two large‐scale current systems in the North Atlantic—the Atlantic meridional overturning circulation (AMOC) and the North Atlantic subpolar gyre (SPG). Both current systems are affected by changes in surface winds and the density pattern of the North Atlantic. We find that the location where the densest water is formed controls how the SPG interacts with the AMOC. Under favorable conditions, the effects of wind and density combine in such a way that changes in the SPG cause abrupt changes in the AMOC. Key Points: Millennial‐scale, self‐sustained oscillations of the ocean circulation occur in a climate model simulationThe oscillations are driven by the interaction between the Atlantic meridional overturning circulation (AMOC) and the subpolar gyre (SPG)The AMOC‐SPG coupling is controlled by a wind‐driven and a density‐driven feedback; the coupling sign depends on the dominant feedback [ABSTRACT FROM AUTHOR] more...

The climate of the western Mediterranean was characterized by a strong precipitation gradient during the Holocene driven by atmospheric circulation patterns. The scarcity of terrestrial paleoclimate archives has precluded exploring this hydroclimate pattern during Marine Isotope Stages 5 to 3. Here we present stable carbon and oxygen isotope records from three flowstones from southeast Iberia, which show that Dansgaard/Oeschger events were associated with more humid conditions. This is in agreement with other records from the Iberian Peninsula, the Mediterranean, and western Europe, which all responded in a similar way to millennial‐scale climate variability in Greenland. This general increase in precipitation during Dansgaard/Oeschger events cannot be explained by any present‐day or Holocene winter atmospheric circulation pattern. Instead, we suggest that changes in sea surface temperature played a dominant role in determining precipitation amounts in the western Mediterranean. Plain Language Summary: Climate events characterized by a sudden temperature increase of up to 10 °C occurring in less than a few decades during the last glacial are recorded in Greenland ice cores. These abrupt warmings, the Dansgaard/Oeschger events, affected large regions of the Northern Hemisphere. The understanding of the regional response in precipitation during these climate shifts is limited for the western Mediterranean, due to the restricted number of terrestrial climate records that cover the last glacial period at sufficient resolution. Speleothems and their stable isotope compositions allow to trace changes in climate and vegetation based on an accurate chronological framework. Here we present a speleothem stable isotope record that shows that the Dansgaard/Oeschger events were associated with increased rainfall and a denser vegetation in the western Mediterranean. A similar pattern was observed for western Europe and other parts of the Mediterranean, and we propose that this was related to generally higher sea surface temperatures of the surrounding oceans rather than a reorganization of atmospheric circulation. Key Points: Western Mediterranean precipitation responded to Greenland interstadials and stadials in a coherent mannerDansgaard/Oeschger interstadials were accompanied by humid climate conditions over the western MediterraneanAtmospheric circulation patterns did not induce spatial differences in precipitation during the last glacial as they did during the Holocene [ABSTRACT FROM AUTHOR] more...

In this paper, we present new evidence regarding a Marine Isotope Stage 3 (MIS3) transgression on the south-eastern Brazilian coast (Baixada Santista coastal plain). Data collected from a Standard Penetration Test (SPT) drilling reveal the occurrence of myxohaline sediments between cal BP 45,000 and 41,000. A deeper sequence, which shows a clear transition from terrestrial to a myxohaline environment, was associated with MIS5e. Organic and inorganic proxies have been used to recognize the variations on the terrestrial/myxohaline/marine deposits, as well as to infer about climate and energy of the depositional environment. Environmental change, which could correspond to a sea-level peak or the occurrence of drier conditions, was recognized between 43,000 and 42,000 cal BP. The results reinforce the need for future works on MIS3 variability on the South American Atlantic coast. [ABSTRACT FROM AUTHOR] more...

Relative to the periods that immediately follow and precede it (which broadly encompass the Later Stone Age on the one hand and the Howieson's Poort and Still Bay Industries on the other), Marine Isotope Stage (MIS) 3 remains archaeologically unexplored in southern Africa. This situation is all the more striking given its importance in Western Eurasia, where Neanderthals were replaced by anatomically modern humans, and in Sahul, which was colonized de novo at this time. One reason for the neglect of MIS 3 has been the longstanding difficulty of dating beyond the limits of the radiocarbon technique, another, the assumption that human numbers in southern Africa at this time were dramatically reduced. Drawing attention to new developments in dating and palaeoenvironmental research, this paper argues that the case for population decline and aridity has been massively overstated. It reviews the archaeological record for the period 60-25 000 years ago and then sets out a series of questions that warrant attention in future research. It also offers suggestions as to how that research might best be pursued. [ABSTRACT FROM AUTHOR] more...