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International audience; Middle Pleistocene glaciation in the Pyrenees is still poorly documented, but the record of ice fluctuations that occurred before 29 ka within the time span of the Late Pleistocene has benefited from a growing catalogue of geochronological data. Here we provide an exhaustive review of results obtained from different generations of ice-marginal deposits for that period, including 14C ages from glaciolacustrine deposits, 10Be and 36Cl exposure ages from boulders embedded in moraines and/or glacially scoured bedrock steps, and optically stimulated luminescence ages from glaciofluvial outwash terraces. Data currently available indicate that the most extensive Pyrenean glaciation of the Late Pleistocene occurred prior to the Last Glacial Maximum (LGM), but that this outermost stadial position (local LGM) was reached on not just one, but several occasions between MIS (marine isotopic stage) 5b (or MIS 4) and MIS 3. Some preliminary results also document major glacier fluctuations during MIS 3.

Investigation of sea-level positions during the highly-dynamic Marine Isotope Stage 3 (MIS 3: 29–61 kyrs BP) proves difficult because: (i) in stable and subsiding areas, coeval coastal sediments are currently submerged at depths of few to several tens of meters below the present sea level, (ii) in uplifting areas, the preservation of geomorphic features and sedimentary records is limited due to the erosion occurred during the Last Glacial Maximum (LGM) with sea level at a depth of −130 m, followed by marine transgression that determined the development of ravinement surfaces. This study discusses previous research in the Mediterranean and elsewhere, and describes new fossiliferous marine deposits overlaying the metamorphic bedrock at Cannitello (Calabria, Italy). Radiocarbon ages of marine shells (about 43 kyrs cal BP) indicate that these deposits, presently between 28 and 30 m above sea level, formed during MIS 3.1. Elevation correction of the Cannitello outcrops (considered in an intermediate-to-far-field position with respect to the ice sheet) with the local vertical tectonic rate and Glacial Isostatic Adjustment (GIA) rate allows the proposal of a revision of the eustatic depth for this highstand. Our results are consistent with recently proposed estimates based on a novel ice sheet modelling technique.

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 simulation. The 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.

The evolutionary dynamics of El Nino Southern Oscillation (ENSO) over the last glacial period remains understudied, despite its potential in providing a “cold case” for climate sensitivity studies. Here, we investigate SE Asian-Pacific paleoclimate records to decipher the dominant underlying mechanism that governed tropical Asian-Pacific hydrology during MIS 3. Our results suggest that the glacial emergence of the Sunda Shelf likely altered the atmospheric circulation pattern in Southeast (SE) Asia and led to the realignment of rainfall patterns between Thailand and Indonesia during the last glacial period. We also propose that the long-term hydrological regime change in the tropical Asian-Pacific region during MIS 3 was mainly influenced by an El Nino-like mechanism. An intense El Nino-like condition led to strong aridity in SE Asia during mid MIS 3. By late MIS 3, an enhanced seasonality dampened the intensity of the El Nino-like conditions, thus, leading to muted aridity in SE Asia. The alternating warm and wet summer months and droughts during winter favoured the proliferation of C4 plant types in Northern Thailand from mid MIS 3 to late MIS 3.

In this study, we analysed the relative size variations of the first lower molar of the common vole Microtus arvalis and the field vole Microtus agrestis from three Late Pleistocene sites with long sequences: Fumane Cave (north-eastern Italy), Portalon and Arbreda Cave (northern and north-eastern Iberian Peninsula). The relative size variations of the two species have been quantified applying the Lagr/Larv index. We tried to relate the changes in the index values to the climatic fluctuations that characterize Marine Isotope Stage (MIS) 3 and 2. The obtained results are compared with previous studies of palaeoclimatic and palaeoenvironmental reconstructions to investigate the efficacy of the Lagr/Larv index as proxy for climatic oscillations through MIS 3-2. The data have also been compared with other available data from Late Pleistocene sites of Spain, Italy, and Hungary, to analyse the responses of the two species to the climatic oscillations in different geographic and climatic areas. Our study showed that the Lagr/Larv index is a potential tool to identify climatic oscillations and changes between humid/dry conditions in Southwestern Europe.

The Abric Romaní site (Capellades, Barcelona, Spain) constitutes a key site for understanding the latest Neanderthal occupations in Western Europe. Here we present a comprehensive systematic and taphonomic analysis of a small-mammal assemblage from Level O of the Abric Romaní site, with the aim of reconstructing the paleoecological context in which the Neanderthals lived. The assemblage, which probably dates from a stadial episode between Interstadial 15 and Interstadial 14, contains fifteen small mammal species, including species uncommon for the northeast of Iberia, such as Sciurus vulgaris, Nyctalus lasiopterus and Pipistrellus pipistrellus. Taphonomic studies suggest a predatory origin for the assemblage, probably related to Strix aluco, and paleoecological inferences suggest lower temperatures (−3/−4 °C) and higher rainfall (+70/+170 mm) than at present and a landscape dominated by an open forest with watercourses. The new data improve our knowledge of trends associated with Marine Isotope Stage 3 that affected Neanderthal populations in the Iberian Peninsula, showing that the Neanderthals were well adapted to cooler and wetter conditions across Iberia., This research was supported by the Ministry of Science, Innovation and Universities of the Spanish Government, project n° HAR2016-76760-C3-1-P, and the Catalonian Government, project n° SGR 2017-836. The Departament de Cultura (Servei d'Arqueologia i Patrimoni) of the Generalitat de Catalunya (2014/100576), the Diputació de Barcelona, the Ajuntament de Capellades, and Arts Gràfiques Romanyà-Valls S.A. provided support for the excavations. J.M. López-García was supported by a Ramón y Cajal contract (RYC-2016- 19386) with financial sponsorship from the Spanish Ministry of Science, Innovation and Universities. A. Bargalló was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Action grant agreement (PREKARN n° 702584).

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. RESUMO: Neste artigo, apresentamos novas evidências sobre a transgressão ocorrida Estágio Isotópico 3 (MIS3) na costa do sudeste do Brasil (Baixada Santista). Dados coletados por meio de um ensaio de penetração em solo (SPT) revelam a ocorrência de sedimentos mixohalinos entre 45.000 e 41.000 anos a.P. Uma sequência mais profunda, que mostra clara transição de ambiente continental para um mixohalino, foi associada ao Estágio Isotópico 5e (MIS5e). Marcadores orgânicos e inorgânicos foram usados para reconhecer as variações dos ambientes terrestre/mixohalino/marinho, bem como inferir sobre o clima e a energia do ambiente deposicional. Uma mudança ambiental, que poderia corresponder a um pico do nível do mar ou à ocorrência de condições mais secas, foi reconhecida entre 43.000 e 42.000 anos a.P. Os resultados reforçam a necessidade de futuros trabalhos sobre a variabilidade do MIS3 na costa atlântica sul-americana.

Palynology of fossil faeces is still extremely rare and its contribution to the interpretation of the environment undervalued. In this paper we present the results of pollen analysis performed on cave hyena coprolites [Crocuta crocuta spelaea (Goldfuss, 1832)] from Marine Isotope Stage 3 (MIS 3) sites of Cava Muracci (Cisterna di Latina, central Italy) and Tana delle Iene (Ceglie Messapica, southern Italy). This study provides new insights into the vegetation of the Late Pleistocene of peninsular Italy, until now known only through long pollen records. It also shows how the content of coprolites, combined with faunal data and geochronological investigations, can represent a potential integrative source of palaeoclimatic proxy data. Our results indicate that the surroundings of both of the hyena dens were characterised by a patchy landscape with open lowlands dominated by steppe and grassland vegetation, while a few mesophilous and thermophilous trees were present in more humid areas, probably along the marine coast and inland. The harsh glacial climate appears to have been milder at Cava Muracci than at Tana delle Iene. This could be due either to the different environmental features of the two sites or to the high climatic variability that occurred during MIS3.

International audience; Mineralogical and sedimentological records from the Gulf of Mexico (GOM) reveal major changes in the terrigenous particles provenance during the Marine Isotopic Stage 3 (MIS3) that likely resulted from modifications of the environmental conditions – including glacial activity and precipitation distribution – over the North American continent. The southeastern margin of the Laurentide Ice Sheet (LIS) was active throughout the entire MIS3, whereas the southwestern margin contributed to short-term meltwater events only during late MIS3. Some of the major mineralogical changes cannot be attributed to glacial activity but rather result from the changes in precipitation distribution. Combining sedimentological records from the GOM with previously published climate-related archives from the North American continent allows the reconstruction of two main schematic patterns of moisture inflow and precipitation distribution that may have prevailed during MIS3. Meltwater discharges contribute to modifying the LIS configuration and the GOM hydrological properties, ultimately affecting large-scale oceanic circulation and may have influenced atmospheric re-organizations although the insolation variation rate appears to be the main driver of the system.

Here, we establish a spatiotemporal evolution of the sea-surface temperatures in the North Atlantic over Dansgaard-Oeschger (DO) events 5-8 (approximately 3040 kyr) using the proxy surrogate reconstruction method. Proxy data suggest a large variability in North Atlantic sea-surface temperatures during the DO events of the last glacial period. However, proxy data availability is limited and cannot provide a full spatial picture of the oceanic changes. Therefore, we combine fully coupled, general circulation model simulations with planktic foraminifera based seasurface temperature reconstructions to obtain a broader spatial picture of the ocean state during DO events 5-8. The resulting spatial sea-surface temperature patterns agree over a number of different general circulation models and simulations. We find that sea-surface temperature variability over the DO events is characterized by colder conditions in the subpolar North Atlantic during stadials than during inter-stadials, and the variability is linked to changes in the Atlantic Meridional Overturning circulation and in the sea-ice cover. Forced simulations are needed to capture the strength of the temperature variability and to reconstruct the variability in other climatic records not directly linked to the seasurface temperature reconstructions. This is the first time the proxy surrogate reconstruction method has been applied to oceanic variability during MIS3. Our results remain robust, even when age uncertainties of proxy data, the number of available temperature reconstructions, and different climate models are considered. However, we also highlight shortcomings of the methodology that should be addressed in future implementations. European Research Council under the European Community's Seventh Framework Programme/ERC [610055]; Centre for Climate Dynamics at the Bjerknes Centre FP7/2007–2013/ERC

13 páginas, 7 figuras, 2 tablas., The Rano Aroi mire on Easter Island (also known as Rapa Nui; 27°09′S, 109°27′W, 430 m above sea level) provides a unique non-marine record in the central South Pacific Ocean for reconstructing Late Pleistocene environmental changes. The results of amultiproxy study on two cores fromthe center and margin of the Rano Aroimire, including peat stratigraphy, facies analysis, elemental and isotope geochemistry on bulk organic matter, X-ray fluorescence (XRF) core scanning and macrofossil analysis, were used to infer past water levels and vegetation changes. The chronology was based on 18 14C AMS dates for the upper 8.7 m. The extrapolated age for the base of the sequence is 70 kyr,which implies that this record is the oldest paleolimnological record on Easter Island. The recovered Rano Aroi sequence consists of a radicel peat formed primarily from the remains of sedges, grasses and Polygonaceae that have accumulated since Marine Isotopic Stage (MIS) 4 (70 kyr BP) to the present. From 60 to 40 kyr BP (MIS 3), high precipitation/runoff events were recorded as organicmud facies with lighter δ13C, low C/N values and high Ti content, indicating higher detritic input to themire. A gradual shift in δ13C bulk organic matter from −14% to −26%, recorded between 50 and 45 cal kyr BP, suggests a progressive change in local peat-forming vegetation from C4 to C3 plant types. Post-depositional Ca and Fe enrichment during sub-aerial peat exposure and very low sedimentation rates indicate lower water tables during Late MIS 3 (39– 31 cal kyr BP). During MIS 2 (27.8–19 cal kyr BP), peat production rates were very low, most likely due to cold temperatures, as reconstructed from other Easter Island records during the Last Glacial Maximum (LGM). Geochemical and macrofossil evidence shows that peat accumulation reactivates at approximately 17.5 cal kyr BP, reaching the highest accumulation rates at 14 cal kyr BP. Peat accretion decreased from 5.0 to 2.5 cal kyr BP, coinciding with a regional Holocene aridity phase. The main hydrological and environmental changes in Rano Aroi reflect variations in the South Pacific Convergence Zone (SPCZ), Southern Westerlies (SW) storm track, and South Pacific Anticyclone (SPA) locations., This research was funded by the Spanish Ministry of Science and Education through the projects LAVOLTER (CGL2004-00683/BTE), GEOBILA (CGL2007-60932/BTE) and CONSOLIDER GRACCIE (CSD2007-00067) and an undergraduate grant JAE (BOE 04/03/2008) to Olga Margalef.