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By combining a multidisciplinary approach and an intensive program of scientific techniques, this paper provides a comprehensive overview of salt production at the Villafáfila lagoons (Zamora, Spain) in prehistoric times. During the Late Chalcolithic and the Early/Middle Bronze Age salt was obtained by boiling brine from salt lagoons. In many parts of western and central Europe at the time the standard procedure for forcing evaporation usually involved the use of crudely fired clay vessels (briquetage) to concentrate brine, and then to mould salt. We suggest that the methods during the final stages of the process differed at Villafáfila, having found evidence of basketry and textiles, which may have been used in the step of crystallization/transport of salt in cake, instead of the small ceramic salt moulds which would be expected in such sites. The role of salt within the socioeconomic setting of the 3rd and 2nd millennia BCE in Central Iberia is also assessed. It is argued that the production and distribution of salt contributed significantly to the political economy, as elites controlled this activity, supporting the idea that salt was a prestige good that contributed to the accumulation of wealth. There is also evidence of ritual practices in the salt-processing areas, as human burials and animal sacrifices have been documented in the excavated sites. • Archaeological evidence shows the production of salt at the Villafáfila lagoons by the late 3rd millennium BCE, during the Beaker period. • Brackish water was boiled in large ceramic vessels supported by clay or stone pedestals. • Techniques evolved during the Early Bronze Age, when pedestals were replaced by clay-walled kilns. • Absence of genuine briquetage, and of small ceramic pots used as salt moulds. • Possible use of baskets and textiles sacks as moulds. [ABSTRACT FROM AUTHOR]

Daily insolation at a given latitude is often used in the explanation of the long-term variations of paleoclimate records. However, the length of astronomical seasons, which has been paid less attention, could also be important. This paper provides an original calculation of the length of these seasons using the eccentric anomaly. The past and future long-term variations as well as the spectral characteristics of the length of astronomical seasons, of the total and average insolation over the astronomical seasons and of the caloric insolation are shown and compared. The length of astronomical seasons is only a function of climatic precession. The total irradiation for a given latitude and an astronomical season is mainly a function of obliquity except that it is mainly a function of eccentricity in a latitudinal band that is season dependent and from where the phase between obliquity and total irradiation reverses (e.g. ∼11.5°N for the astronomical northern hemisphere summer half-year). The spectral characteristic of the mean insolation over the astronomical summer half-year varies in latitude and time. It contains stronger obliquity signal in high latitudes than in low latitudes, but the obliquity signal already gets very weak at 45°N/S leaving the dominance of climatic precession between 45°N and 45°S. The variation of the mean summer half-year insolation over the last 1 Ma is characterized by a Mid-Brunhes transition at ∼450 ka BP, with a dominant role of climatic precession at all latitudes before ∼450 ka BP but significantly enhanced role of obliquity in high latitudes after this time. The simultaneous weakening of the variations of climatic precession and obliquity around 800 ka ago, a time corresponding to the Mid-Pleistocene Transition, leads to weak variations in both total and mean seasonal insolation. The insolation of a specific case, the Holocene, is finally discussed. Depending on the sensitivity to different types of insolation, different climate variables and regions could show different evolution and trend during the Holocene. • An original calculation of the length of the astronomical seasons is provided. • Precession and obliquity contribute differently to the length of astronomical seasons and to different insolation metrics. • Distinctive variations of total and mean seasonal insolation characterize the Mid-Brunhes and Mid-Pleistocene transitions. • Different insolation metrics display different trend over the Holocene. [ABSTRACT FROM AUTHOR]

The central sector of the Ebro Depression is characterized by an abundance of isolated buttes with relict talus flatiron morphologies and block slopes on the footslopes. This paper presents two unusual study cases where the block slopes are aligned in parallel with the retreating escarpment. The evolutionary process of both buttes started with the formation of talus flatirons and ended with aligned block slopes. This is because both buttes initially had a detrital caprock (Pleistocene pediment) which eroded away to expose a sandstone layer that functioned as a new caprock and so changed the slope dynamics. Seven stages were identified at La Cobeta butte and five at Puyalón butte. The relative ages obtained for stages II and IV enabled an estimation of the escarpment retreat rates. The chronologies of the other stages of block alignments were estimated using Schmidt-hammer rebound values. The estimated age of the stage II (ca. 6588-6222 cal yr BP) coincides with three radiocarbon datings obtained in the deposit. Stage III (ca. 4235-3684 cal yr BP) is contemporary with the 4.2 Bond event. Stage IV (ca. 2800-2500 cal yr BP) coincides with the 2.8 Bond event and is associated with ceramic potsherds and radiocarbon datings. Stages V and VI developed during the Warm Roman period and the Medieval Climatic Anomaly respectively. Lastly, stage VII was formed during the Little Ice Age. The information obtained regarding the morphological arrangement improves our knowledge of the regional evolutionary model where talus flatirons and block slopes develop in a semiarid environment. • Slope dynamics and evolution can be establish with a block alignments study. • Schmidt-hammer records were applied to make chronological estimations. • Chronological estimations were partially controlled using absolute and relative datings. • Seven evolutionary stages including talus flatiron and block alignments were established. • Block alignments provide more accurate data than talus flatiron on scarp retreat rates. [ABSTRACT FROM AUTHOR]

Mainland Southeast Asia experiences complex and variable hydroclimatic conditions, mainly due to its location at the intersection of Asian monsoon subsystems. Predicting future changes requires an in-depth understanding of paleoclimatic conditions that is currently hindered by a paucity of records in some regions. In this paper, we present the first speleothem stable isotope records from western Thailand detailing the Bølling-Allerød interstadial, Younger Dryas termination, and early- to mid-Holocene period. We find evidence of higher precipitation during the Bølling-Allerød (14,321–12,824 years before present (1950: BP)) compared to a Younger Dryas termination that starts 11,702–11,674 BP, has a rapid shift centered on 11,660–11,641 BP, and ends 11,603–11,589 BP. In addition, our records show Holocene monsoon intensity peaking at 8250 BP or before, a multi-millennia delay from the Northern Hemisphere summer insolation peak, followed by a trend to drier conditions until at least 750 BP. Assessment of the timing of the Younger Dryas termination in paleoclimate records across Southeast Asia reveals an earlier shift of the Indian Summer Monsoon to global climate shifts when compared to East Asian Summer Monsoon records. The causes of this are currently unknown. Some potentially important aspects include: an Indian Summer Monsoon influence on East Asian Summer Monsoon strength via the Indian Ocean Dipole climate pattern, the role of the Tibetan Plateau in monsoon dynamics, and exposure of the Sundaland shoreline. More high-resolution paleoclimate records, especially on the pathway of Indian Summer Monsoon to East Asian Summer Monsoon, are required for further discussion on the mechanisms controlling the differences between climate regimes. • We present two new speleothem stable isotope records from western Thailand. • Conditions trend wetter during the Bølling-Allerød. • Early and abrupt termination of the Younger Dryas (11,675–11,600 BP, ±73 years). • Change Point Analysis of records finds earlier rapid shift in Indian Summer Monsoon. • Distinct trend of increasing δ18O and δ13C values throughout Holocene. [ABSTRACT FROM AUTHOR]

This paper explores the Holocene climatic dynamics of South Africa's southern Cape, a region that supports a large proportion of the Greater Cape Floristic Region and contains an array of important archaeological sites. While South African climates are generally characterised by marked rainfall seasonality, the southern Cape is currently situated at the interface between tropical and temperate climate systems, resulting in a largely aseasonal rainfall regime. This regime, however, is thought to have been particularly sensitive to past changes in late Quaternary boundary conditions, meaning that variability in either tropical or temperate systems could have significant environmental impacts. Evidence of past climate change, however, remains limited. We present a 9000-year record of hydroclimatic variability obtained from rock hyrax midden stable nitrogen records, from Papkuilsfontein, on the southern slope of the Anysberg Mountains. Resolved to an average 6-year resolution and spanning the period c. 9050 cal yr BP to 1990 CE, this is the highest resolution Holocene record from southern Africa and presents a unique opportunity for the detailed study of the primary drivers and spatial gradients of Holocene climate change in the southern Cape. The data indicate a long-term decrease in aridity across the Holocene and a pattern of variability that reveals remarkable similarities with records from the South African tropics and El Niño–Southern Oscillation proxies, highlighting the significance of tropical systems as drivers of Holocene climate change in the region. This substantially expands what has been previously considered to be the zone of tropical influence, extending from a coastal phenomenon associated with heat transport via the Agulhas Current to encompass much, if not all, of the Agulhas Plain south of the Cape Fold Mountains. These findings provide a valuable new climatic framework for contextualizing changes in ecological and archaeological records in the southern Cape, and contribute to a more comprehensive understanding of the spatio-temporal dynamics of climate systems in southern Africa. • Sub-decadal 9000-year record of aridity from South Africa's southern Cape. • Reveals dominance of tropical forcing across the southern Cape and Agulhas Plain. • ENSO variability indicated to be important driver of regional climate change. • Presents high-resolution framework for study of human-environment interactions. [ABSTRACT FROM AUTHOR]

During the Bronze and Iron Age, Sardinia was home of one of the most technologically advanced Mediterranean societies (the Nuragic culture). Given its key geographical location, the island was also the fulcrum of deep cultural exchanges. Toward the end of the Iron Age, Phoenicians, and especially Carthaginians and Romans, massively frequented Sardinia for different purposes. This marks an important cultural transition for the region, as the ancient Nuragic-related society terminated. At the same time, this impacted the subsistence and land use practices. Together with middle to late Holocene climate changes, the novel anthropic activities had a pivotal role in shaping the landscape around the island. However, high resolution climate and environmental records for these culturally important phases are still lacking in Sardinia. Thus, this paper explores palaeoenvironmental changes from the Bronze Age to post Iron Ages times by using carbonate speleothems from Suttaterra de Sarpis Cave (Urzulei, central east Sardinia), strategically located nearby the Or Murales Nuragic Village. U–Th ages (n = 20) indicate that five stalagmites comprehensively span the last ∼7000 years. Peculiarly, they all show an evident stratigraphic discontinuity. Age models attest that hiatuses can be at times associated with the discontinuities, spanning periods of ∼1200 to ∼200 years. Importantly, the discontinuities occurred from the Late Iron Age to the Roman period. Based on fabric observations, trace elements and δ13C- δ18O analyses, the discontinuities are primarily attributed to a progressive change of land use above the cave. We suppose that deforestation aimed to clearance for agriculture and livestock practices probably was the most impacting factor for infiltration dynamics and soil state, thus affecting the studied speleothems, although archaeological and historical data are absent for the specific study area. Instead, this is in line with the cultural transition occurring in Sardinia toward the end of the Iron Age, with novel agricultural practices imported by the overseas populations. The anthropic disturbance to the millennial-long karst equilibrium possibly overprinted the response of speleothem proxies to climate oscillations, although future higher resolution analyses are necessary to better investigate the evolution of climate during the Holocene as well as its role in the development of ancient civilizations. Indeed, this is the first speleothem-based Holocene palaeoenvironmental reconstruction accomplished in Sardinia. Considering the paucity of natural lakes in this key location, speleothems here demonstrate their potential in exploring human-driven palaeoenvironmental changes during times of cultural transitions within the Mediterranean context. • The first Holocene speleothem paleoenvironmental record from Sardinia (Italy). • Changes in geochemical and physical speleothems' properties point to variation of land use. • Land use variation is connected to cultural shifts during intra- and post-Nuragic period. [ABSTRACT FROM AUTHOR]

Abstract Greenland Ice Sheet (GrIS) covers an area of 1.7 million km2. It has been an important source of climate information and the air temperature history of Greenland is well known. However, the thermal history and temperature conditions of the Greenland bedrock are poorly known. There are only few records on the temperature of the proglacial bedrock and no records on bedrock temperature underneath the ice sheet. The Greenland Analogue Project (GAP) recently investigated hydrological, hydrogeological and geochemical processes in Kangerlussuaq, West Greenland. Because permafrost has a major hydrological impact in Arctic regions, the cryogenic structure of the bedrock was an important research topic. From previous studies it was already known that Kangerlussuaq is located within the zone of continuous permafrost. Temperature profiling in a new research borehole, extending horizontally 30 m underneath the ice sheet, revealed that permafrost is 350 m deep at the ice margin. This result raised the question how far the permafrost extends under the ice sheet? In order to investigate the thermal properties, we made a series of electromagnetic (EM) soundings at the ice margin area – on proglacial area and on the ice sheet – and detected, that subglacial permafrost extends at least 2 km from the ice margin to inland. We also observed a patchy unfrozen sediment layer between the ice and the frozen bedrock. Possible existence of subglacial sediments and their role in ice dynamics has been debated in many recent papers. Our successful campaign shows that geophysics can be used for bedrock investigations through thick ice, which is known to be challenging for electromagnetic methods. Our results provide the first direct evidence supporting the proposed Holocene ice re-advance over frozen ground, and contribute to the discussion on the rapid climate changes in past, to the future of the ice sheet under warming climate and hydrogeology at the ice margin. Highlights • This paper is related to an international research project, the Greenland Analogue Project. • Electromagnetic method was able to discriminate unfrozen and frozen ground. • The first published description of cryogenic structure under continental ice sheet. • Ice re-advance over permafrost evidencing significant Holocene retreat to the east. • A literature review of the Holocene deglaciation of West Greenland. [ABSTRACT FROM AUTHOR]

The formation and evolutionary history of intracontinental, tideless sea barrier coasts is still poorly known in comparison to open-ocean and tidal sea barrier systems. This paper describes the morpho-geological structure of the barriers and its substrate along a 90-km section of the middle part of the Polish southern Baltic coast. The main goal of the study is a better insight into the evolution of the barriers in case of sand scarcity and relations to sea level changes. The study area was examined by analysis of the published and historical data from 120 borehole profiles supplemented by new 18 core drillings. In addition to lithological and biostratigraphical data, a large set of radiocarbon ages was acquired and analysed. The barriers during its whole middle and late Holocene history were retrogradational despite of varied geological and morphological features of its substrate. The average rate of barrier's retreat has shown considerable variation in a close relation to the rates of sea-level rise. During the period 8500-7500 yr b2k when the sea level rose by 6–5 mm/yr, the coast retreated ca. 4.6–3.5 m/yr. Between 7500 and 6000 yr b2k, the sea-level rise slowed down to ca. 1.7 mm/yr and the rate of coastline retreat fell to ca. 1.0 m/yr. During the last 6000 years, coastal retreat slowed down to ca. 0.3 m/yr as the average sea level rise was ca. 0.5 mm/yr. The permanent retrogradational history of the barrier coast, even in the case of sand availability in the barrier's substrate, is explained by the existence of a divergence zone of longshore currents and a related source zone for the alongshore sandy streams. The divergence zone is present within the study area not only today, but it has existed most probably also at least since the beginning of the late Holocene. As a result, the erosional trend (sand scarcity) dominates here, which contributes to the presence of retrogradational barriers. • Recognition of morpho-geological structure of the barrier and its substrate. • New middle and late Holocene relative sea-level curve from southern Baltic Sea. • The evolution of the barriers in case of sand scarcity and relations to sea level changes. [ABSTRACT FROM AUTHOR]

This paper introduces a series of articles assembled in a special issue that explore Holocene climate evolution, as recorded in lakes on the Island of Amsterdamøya on the westernmost fringe of the Arctic Svalbard archipelago. Due to its location near the interface of oceanic and atmospheric systems sourced from Arctic and Atlantic regions, Amsterdamøya is a key site for recording the terrestrial response to marine and atmospheric changes. We employed multi-proxy approaches on lake sediments, integrating physical, biogeochemical, and isotopic analyses to infer past changes in temperature, precipitation, and glacier activity. The results comprise a series of quantitative Holocene-length paleoclimate reconstructions that reveal different aspects of past climate change. Each of the four papers addresses various facets of the Holocene climate history of north-western Svalbard, including a reconstruction of the Annabreen glacier based on the sedimentology of the distal glacier-fed lake Gjøavatnet, a reconstruction of changing hydrologic conditions based on sedimentology and stratigraphy in Lake Hakluytvatnet, reconstruction of summer temperature based on alkenone paleothermometry from lakes Hakluytvatnet and Hajeren, and a hydrogen isotope-based hydrological reconstruction from lake Hakluytvatnet. We also present high-resolution paleomagnetic secular variation data from the same lake, which document important regional magnetic field variations and demonstrate the potential for use in synchronizing Holocene sedimentary records in the Arctic. The paleoclimate picture that emerges is one of early Holocene warmth from ca. 10.5 ka BP interrupted by transient cooling ca. 10-8ka BP, and followed by cooling that mostly manifested as two stepwise events ca. 7 and 4 ka BP. The past 4ka were characterized by dynamic glaciers and summer temperature fluctuations decoupled from the declining summer insolation. [ABSTRACT FROM AUTHOR]

The progradation of the Medjerda delta has been the subject of many studies since the 19th century. The scale and the rapidity of this phenomenon interested researchers in various fields early on, such as geomorphology, geology, palaeogeography, history, archaeology, or geoarchaeology. Indeed, the delta prograded by around 10 km over 3 millennia. At the time of its foundation supposedly at the end of the 12th century BC, the Phoenician city of Utica was located on a promontory bathed by the sea, but the sediments carried by the Medjerda progressively sealed the bay, leaving the tip of the Utica promontory now 10 km inland. This area is therefore an exception to the general pattern along the Tunisian coast, since as over the same period everywhere else there is a regression of the coastline, owing to a sea level rise of several decimeters. Based on multi-proxy analyses of two coring transects, this paper aims to reconstruct the palaeoenvironments and the palaeogeography of the Medjerda delta's progradation since the mid-Holocene, some aspects of which are described in ancient sources. The results highlight in particular an episode of high-intensity flooding around the 4th century AD, which is consistent with episodes of high floods and an increase in sedimentation rates recorded in the watershed at the end of the Roman period. The gradual abandonment of the city of Utica can certainly be related to the activity of the Medjerda River, but our results show that it is because of an increase of fluvial sediment contribution in connection with an erosive crisis in the headwaters, and not because of the change of course of the river, which had occurred long before. • The Medjerda delta's progradation reached 10 km over 3 millennia. • The reconstruction of the palaeogeography helps to better understand the foundation of Utica and its gradual abandonment. • A wide bay around Utica since the 6th mill. BC, progressively sealed by the alluvium of the Medjerda from the 1st c. BC. • The results highlight in particular an episode of high-intensity flooding around the 4th century AD. • The isolation of Utica from the sea is due to an erosive crisis generated by climatic and probably anthropogenic factors. [ABSTRACT FROM AUTHOR]

This paper presents the archaeobotanical and archaeozoological data of the 6th to 4th millennia cal BC sequence recently documented at Dehesilla Cave, and puts forward an interdisciplinary approach to the significant ecological patterns from this key archaeological site in the Southern Iberian Peninsula throughout the entire Neolithic period. indicate an ecological scenario characterised mainly by oak and wild olive forests, and human populations with agricultural practices and herds of mainly sheep and goats. However, this general panorama must have undergone several remarkable fluctuations. The first Neolithic populations of Dehesilla Cave, dated around the mid-6th millennium cal BC and linked to the Mediterranean impressa pottery complex, do not yet display evidences of agriculture, while all of the subsequent Early Neolithic levels indicate a model of small-scale populations with a mixed economy but still with a greater component of livestock. The second quarter of the 5th millennium cal BC shows a marked accentuation of the monoculture of naked wheats, which could have been related to the transition from an intensive to an extensive farming system. This may have entailed a selective pressure on the environment, leading to a large deforestation spanning the second half of the 5th millennium cal BC and the constitution of relatively open thermo-Mediterranean forests with a physiognomy similar to that of the dehesa. These ecological patterns are discussed within a review of the current state of the art of the use of plant and animal resources by the Neolithic human populations in the southern regions of the Iberian Peninsula. • A multidisciplinary archaeobotanical and archaeozoological approach is carried out. • A key Neolithic site in the Southern Iberian Peninsula is excavated and examined. • The first local Neolithic populations show evidence of livestock without agriculture. • A monoculture based on naked wheats was successful during 4800-4500 cal BC. • Human pressure on ecosystems led to the spread of open thermo-Mediterranean forests. [ABSTRACT FROM AUTHOR]

The use of coastal resources has been crucial for human diet and social behaviour evolution has been extensively documented since the Middle Palaeolithic, mainly in the western Mediterranean and southern Africa. In southern Iberia, the mollusc assemblages associated with archaeological sites show a continuous record regardless of palaeoclimatic conditions. Among these, limpets are uninterruptedly abundant from the Middle Palaeolithic to the Bronze age with the giant limpets (Cymbula safiana and Patella ferruginea) being present since MIS6. To assess their distribution, predominance, and cultural significance this paper presents the results from an exhaustive archeozoological survey of the southern Iberian region. A total of 1628 specimens have been analysed, including 425 modern (333 C. safiana and 91 P. ferruginea) and 1203 from 60 archaeological deposits deriving from 36 sites, both coastal and continental. Giant limpets' context also has been described and it has been related with a wide variety of deposits ranging from food refuse accumulations to occupations and burials. Detailed morphological and surface analysis allowed us to determine extraction methods and anthropic transformations. On coastal sites, the giant limpet record starts with Neanderthal populations from the Middle Palaeolithic and continues throughout the Upper Palaeolithic, Mesolithic, Neolithic, and Copper Age. On inland sites, giant limpets appear first in reduced numbers during the Late Neolithic and have been often worked into elliptical contours with polished, rib-free, external shell surfaces. In this study, we focus on the Copper Age, when giant limpet use becomes common, and records include tholoi, dolmens and other funerary contexts. The data indicate that the use of P. ferruginea is associated with Los Millares and El Argar cultures. Giant limpets use declines during the Bronze Age probably due to the major cultural shift that occurred during the Chalcolithic to Bronze transition. The data suggest that giant limpets should be considered as proxies of long-range trade during the Chalcolithic. We propose a new hypothesis linking giant limpets symbology with orbital/tidal variations and the ubiquitous use of marine elements as symbolism during this period. Our study highlights the relevance of shells in the reconstruction of the symbolic evolution of prehistoric cultures, as well as their connections with local ecosystem resources and regional commerce networks. • Ecology, exploitation, and potential symbolism of giant limpets found in archaeological sites in southern Iberia. They include data on modern specimens to strengthen their analysis. Works on molluscs in archaeology generally focus on. • Species used mainly as food or for ornaments. In this work we focus on underrepresented species: the giant limpets and the relationship of the cultures of southern Iberia with this resource. • We believe that the data provided is novel and provides a new vision of archaeomalacology. [ABSTRACT FROM AUTHOR]

This paper addresses the first case of perimortem trauma caused by a sharp metal weapon in a pre-Hispanic cranium in Gran Canaria (Canary Islands) dated before the first contacts with Europeans in the late Middle Ages. The fact that metalliferous minerals did not exist in the archipelago confers extraordinary significance to this injury, as evidence of an event involving the arrival of new population after the initial colonization of the Island around the 2nd century CE. The chronocultural context of the violent event is analized in order to evaluate the possible role of this contact in the processes of change among ancient canarians. To this end statistical chronological modelling is assessed to specify timing behind major archaeological expressions of shifts detected on the island. The results question the traditionally proposed isolation for the indigenous population, and reinforce the most recent proposals suggesting migration of new North African people to Gran Canaria and their contribution to the socioeconomical dynamics of the pre-Hispanic society. • A sharp force injury death shows outside contacts for the ancient Canarians • Bayesian modelling of 14C dates sheds light on historical changes • Migratory movements as active factors in the dynamics of socio-economic change [ABSTRACT FROM AUTHOR]

This paper provides the most-accurate sea-level index points (SLIPs) for the Rhine-Meuse Delta (RMD), The Netherlands, identified amidst a wealth of data accumulated in sixty years of research. Following documented protocols, 106 selected radiocarbon dates from peat beds from transgressed valley floor, upper estuarine and back-barrier lagoonal settings were first listed individually, then screened in ensemble on quantified age-depth position and inshore palaeotidal setting. The database contains 50 SLIPs and 56 upper limiting data points spanning a depth range of −34 to −1.5 m. The dates in the database originate from dedicated sea-level research, which kept surface elevation and sampling depth uncertainty small, and sampling of basal-peat beds was favoured, keeping compaction uncertainties small too. The SLIPs cover an age-range of 8.8–3.0 ka BP and are available from Greater Rotterdam and its near offshore. For upper limiting data points, the coverage extends offshore, tracing the Rhine palaeovalley, and reaches back to 11.5 ka BP. The age-depth data density and spatial concentration of subsets of dates allow to perform Bayesian radiocarbon calibration and to reduce temporal uncertainty by 25% for the average sample (1σ age uncertainty ≈ 75 cal. yr), when depth position and rates of relative sea-level rise (RSLR) are used to assign sequence order. Between 8.0–4.5 ka BP, rates of RSLR gradually decreased from 9 to 1 mm/yr. In the millennium before, rates of RSLR were much higher, on average 10 mm/yr, and marked by a sea-level jump between 8.45–8.2 ka BP. A two-phased nature of this jump starts to be resolved, with local magnitudes of 1.7 ± 0.6 m (1σ, first phase) and 0.2 ± 0.2 m (second phase), corresponding to globally-averaged jumps of 2.5 m ± 0.9 m for the first and 0.3 ± 0.3 m for the second phase. For the pre-9 ka BP period, only offshore upper limiting data points are currently available. Until new offshore data are gathered, trends of RSLR before 9 ka BP can only be estimated, fed with global insights in post-glacial eustasy, regional estimates regarding rates of glacio-isostatic adjustments and tectonic subsidence, and sedimentary geological interpretations of scattered basal-peat presence. Image 1 • New Holocene geological sea-level database for the Rhine-Meuse Delta. • Contains 50 sea-level index points and 56 upper limiting data points spanning 11.5–3 ka BP. • 95% of the database entries are derived from basal peat: compaction uncertainties are small. • Relative SLR rates decelerated from 10 mm/yr around 9 ka BP to 1 mm/yr around 4.5 ka BP. • A two-phased 8.44–8.2 ka sea-level jump structure is suggested, the first phase measuring 1.7 ± 0.6 m (= 2.5 ± 0.9 globally). [ABSTRACT FROM AUTHOR]

Fossil pollen assemblages can assist in understanding biome responses to global climate change if there is reasonable probability that they represent specific biomes or bioregions. In this paper, we introduce a novel probabilistic presentation of pollen data and biome assignment. We apply a recently developed pollen-based vegetation classification method utilizing supervised machine learning to Southern Africa modern pollen assemblages. We present an updated modern pollen dataset from Southern Africa, linking the sites to previously defined vegetation units and, ultimately, we generate probabilistic classification for fossil assemblages to reconstruct past vegetation. The modern pollen dataset (N = 211 sites) represents a long vegetation gradient, from desert to forest biomes, capturing broad climate gradients ranging from arid to subtropical. We validate two models using Random Forest algorithm to classify modern vegetation at different spatial resolutions: subcontinental (biomes) and regional (bioregions). When the modern pollen assemblages (N = 164 sites) are used to predict the vegetation types, the classification models are correct in a number of cases. In our dataset of 164 sites, the classification model correctly classifies pollen assemblages from savanna (91% correct), grassland (87%), and coastal forest (82%) vegetation types, while the best results for classification of regional vegetation are achieved for sub-humid savanna (95%), dry savanna (95%), coastal forest (91%), and wet grassland (90%). We apply the models to a fossil pollen sequence at Wonderkrater in the South African savanna, to reconstruct subcontinental and regional changes in past vegetation states over the last 60 000 years. The most probable vegetation state dominating the region since the Late Pleistocene is sub-humid savanna yet grassland occurred at times associated with high vegetation variability. Within the record, the most frequent and amplified variability in the inferred vegetation states occurred during the transitional phase between the Late Pleistocene and the Holocene. The machine learning approach for reconstructing past vegetation, offers a more complex and nuanced view of past vegetation dynamics and has the potential to support quantitative proxy-based techniques for palaeoclimatic reconstructions. • Expanded modern pollen dataset for Southern Africa. • Probabilistic classification for fossil assemblages to reconstruct past vegetation. • Savanna-grassland dynamics reconstructed over the last 60 000 years at Wonderkrater. • Increased oscillations in probabilities of predicted biomes during Younger Dryas. [ABSTRACT FROM AUTHOR]

Abstract Constraining Antarctic ice sheet evolution provides a way to validate numerical ice sheet models that aid predictions of sea-level rise. In this paper we collate cosmogenic exposure ages from exposed nunataks in Antarctica that have been used, or have the potential to be used, to constrain rates of thinning of the Antarctic Ice Sheets since the Last Glacial Maximum. We undertake quality control of the data and adopt a Bayesian approach to outlier detection. Past thinning rates are modelled by Monte Carlo linear regression analysis. We present thinning rates from 23 sites across Antarctica. The resulting data set is the first Antarctic-wide collation of past ice sheet thinning rates and provides an empirical starting point for future model-data comparisons. Palaeo-thinning rates are spatially variable with high rates appearing to correlate to areas of contemporary rapid changes. On centennial timescales past thinning rates are comparable to modern day observations implying that modern day thinning has the potential to persist for centuries in numerous parts of Antarctica. The onset of abrupt thinning from all sites post-dates Meltwater Pulse 1A suggesting that its source region(s) are distal to areas where exposure age constraints on ice surface geometry exist. Highlights • Exposure ages that constrain ice sheet thickness collated from an online database. • Thinning rates are reconstructed from 23 sites across Antarctica. • Palaeo-thinning rates are comparable to modern observations. • Wide-spread thinning during the Holocene, but after Meltwater Pulse 1A. [ABSTRACT FROM AUTHOR]

Abstract The spread of early herders across Africa is a pivotal event in prehistory, but the context of this event remains poorly understood due to a lack of paleoenvironmental data. We present new radiocarbon dates and multi-proxy Holocene paleoecological records for two distinct settings on the pathways through which livestock herding spread across eastern Africa: the Lake Turkana Basin, which has the earliest record of livestock in eastern Africa, and the Lake Victoria Basin, located farther south. Herbivore diet as inferred from tooth enamel carbon isotopes (n = 368), and pollen and leaf wax biomarker data, do not support a uniform ecological response to increased aridity at the end of the African Humid Period ∼5 kya, as had been previously thought. Rather, climate change had basin-specific ecological effects, and these in turn met differing human responses. Rather than extrapolating local ecological effects from regional climate records, archaeologists require basin-specific paleoecological data, deeply integrated with archaeological findings. This paper provides such integration for the first time in eastern Africa. Our results highlight the climatologically and ecologically distinctive areas around lake margins, necessitating future paleoenvironmental and archaeological research in inland areas. Highlights • Holocene climatic and environmental variability played a role in the southward spread of herders across Kenya and Africa. • Holocene climate change is well known, but ecological shifts associated with climatic changes are not. • We present a comprehensive paleoecological reconstruction of two lake basins that document herdering in eastern Africa. • We demonstrate that local rather than regional ecological mechanisms influenced early herder migrations in Africa. [ABSTRACT FROM AUTHOR]

This paper introduces the reader to a special issue of articles that explores links and processes behind societal change, climate change and environmental change in a Holocene perspective in the Mediterranean region. All papers are, by purpose, co-authored by scientists representing different disciplines. The cross-cutting theme has been to reach beyond simple explanations of potential climate-society relationships and advance our understanding on how to improve research methods and theories in the field. The thirteen papers in this issue address these questions in three different ways, by i) conceptual/methodological approaches; ii) review papers; and iii) case studies. [ABSTRACT FROM AUTHOR]

In the course of the Holocene large parts of the Northwest European mainland became overgrown with peat, only a fraction of which has survived to the present day. The diachronic relations between peatland expansion, human habitation trends and vegetation dynamics are poorly understood. Gaining detailed insights in the interrelations between these processes is essential to enhance interpretations of archaeological data on different spatial and temporal scales and to inform cultural heritage management and nature conservation and restoration. To achieve this goal it is key to develop interdisciplinary research designs in which the timing, pace and character of the relevant processes are analysed integrally. In this paper we present a study of the northern Dutch Fochteloërveen area, which is one of the largest and best preserved bog remnants of the Northwest European mainland. We integrate a recently published model on peatland initiation and lateral expansion with an inventory of extant archaeological data and new high-resolution palaeobotanical analyses (plant macro remains and pollen), which produces insights into the dynamic landscape history of this 'drowning' area in hitherto unparalleled detail. Two characteristic phases in the landscape history of the study area (the Late Mesolithic and Middle Roman period) are visualised by means of evidence-based artist impressions. The methodology and results of the study offer inspiration and important material for comparison for similar landscapes across the Northwest European mainland. • Interdisciplinary study improves insight in 'drowning' of Northwest European mainland. • Lateral peatland expansion accelerated between 5500–3500 cal BP. • Human landscape impact altered vegetation composition since the Middle Neolithic. • Peatland expansion mainly affected human habitation in the Iron Age and Roman period. [ABSTRACT FROM AUTHOR]

A fundamental and long-standing question of southern African palaeoclimatology is the way tropical and temperate climate system dynamics have influenced rainfall regimes across the subcontinent since the Last glacial maximum. In this paper, we analyse a selection of recently published palaeoclimate reconstructions along a southwest-northeast transect across South Africa. These records span the last 22,000 years, and encompass the transition between the region's winter and summer rainfall zones. In synthesis, these records confirm broad elements of the dominant paradigm, which proposes an inverse coeval relationship between temperate and tropical systems, with increased precipitation in the winter (summer) rainfall zone during glacial (interglacial) periods. Revealed, however, is a substantially more complex dynamic, with millennial-scale climate change events being strongly – even predominantly – influenced by the interaction and combination of temperate and tropical systems. This synoptic forcing can create same sign anomalies across the South African rainfall zones, contrary to expectations based on the classic model of phase opposition. These findings suggest a new paradigm for the interpretation of southern African palaeoenvironmental records that moves beyond simple binary or additive influences of these systems. [ABSTRACT FROM AUTHOR]

The Magdalen Islands (Québec, Canada) in the centre of the Gulf of St. Lawrence are located in a strategic position for providing an overview of the relative sea-level (RSL) history of the Maritime Provinces of eastern Canada. Although data are available for the coastal terrestrial areas of the Maritimes, data from the Gulf are very scarce and both the RSL and glacio-isostatic adjustment (GIA) models extrapolate for this central region. This study provides new stratigraphic and chronological data from four outcrops and two coring sites on the Magdalen Islands. In addition to the five samples used mainly for age control purposes, nine new luminescence ages are presented. With these new data added to the available literature, a new RSL curve is reconstructed for the LGM to the late Holocene period and a partial curve is proposed for the interval between the late MIS 4 to the MIS 3. Data also indicate a few insights for the MIS 5 period. Results reveal that for the LGM to the late Holocene, the curve corresponds to the J-shaped curve scenario recognized in the literature. The RSL changes during this period are the result of glacio-isostatic rebound, migration and collapse of the peripheral forebulge, and eustatic sea-level changes. For the LGM to the early Holocene, glacio-isostatic depression curves displaying a few local differences are also proposed. For the late Holocene, the data constrain the curve between two types of indicators, i.e. marine and terrestrial, and indicate that the RSL has risen at least 3 m during the last two millennia. Sediments dated to the MIS 5 and the interval between the late MIS 4 and the MIS 3 illustrate that the GIA following the LGM also occurred for the MIS 5 interglacial and the MIS 3 interstadial. Finally, recent GIA models are discussed in light of the results of this paper. [ABSTRACT FROM AUTHOR]

The Middle East is considered a climate change "hot spot", where rainfall is expected to decline in the upcoming decades due to Global Warming. Reconstructing the long-term natural climate variability of this region is critical for understanding and contextualizing the current hydroclimate change and enables evaluating potential mechanisms that govern it. Oxygen isotopes (δ18O) from cave deposits are a high-resolution paleohydrological proxy, which previously has been interpreted as direct measures of rainfall amount. However, cave δ18O is controlled by a series of processes (e.g., evaporation, condensation and rainout history), and therefore, any paleohydrological interpretation using cave δ18O requires a thorough understanding and quantification of the full hydrological cycle. In this paper, we use a simple Rayleigh distillation model to assess the various processes that govern the isotopic composition of precipitation and quantify changes in cloud distillation during the Holocene throughout the Middle East. The results show that a west-east isotopic distillation gradient persisted throughout the Holocene in the Middle East. The early Holocene, coeval with Sapropel 1, was characterized by high distillation and a large west-east distillation gradient. At the end of sapropel 1, distillation dropped and the west-east gradient declined. The middle to late Holocene was characterized by a gradual increase in distillation, however the west-east distillation gradient continued declining. Similarity between the late Holocene distillation reconstruction and the Dead Sea lake-levels, strengthens the reliability of cloud distillation as a suitable hydroclimate proxy. These results show that periods of high distillation in the Levant occurred during both high and low summer insolation (early and late Holocene, respectively), and thus, were most likely the result of two different climatic mechanisms. Our distillation and distillation gradient records provide a new way to characterize the long-term natural climate variability in the Middle East and thus help resolve the climatic mechanisms governing this variability. • Holocene cloud distillation quantified using cave δ18O in Middle East Caves. • High distillation and high continentality characterized Middle East Early Holocene. • High distillation and low continentality characterized Middle East Late Holocene. • Jeita Cave distillation is similar to Dead Sea levels throughout the Holocene. • Different climate mechanisms operated during the Early and Late Holocene. [ABSTRACT FROM AUTHOR]

To understand the relationship between past peoples and the sea in a context of oceanic islands, just as in the case of other cultural behaviours, it is necessary to consider many more factors than the mere proximity to the coast. Traditions, ways of life, sailing ability and knowledge, diet, and so on, determine the way in which this relationship is expressed. This paper addresses this matter through the study of external auditory exostosis (EAE) among the aboriginal population of Gran Canaria. The analysis has been completed by contrasting this bioanthropological marker with such other variables as chronology, territory, social dynamics and environmental changes. The study examined a large sample (MNI = 637) from all over the island and a time interval of more than 1200 years, practically the whole pre-Hispanic period. EAE is present in 17.1% of the total population analysed, with no statistically significant differences between males and females. This high prevalence is even more evident when considering its notable incidence among coastal communities and its chronological concentration, between the 13th and 15th centuries, that is, the last 300 years of the historical sequence considered. On balance, the results indicate relevant variation in the relationship that these populations had with the sea in accordance with the historical processes and social changes that took place over more than a millennium. • Island colonization, migrations and lifestyle changes on an African island. • Historical development of an insular Libyan-Berber population between the 3rd and 15th centuries CE. • Archaeological traces of environmental changes and social transformation. • External auricular exostosis (EAE) as a diachronic marker of the interaction of humans with the marine environment. • Cultural markers in the western confines of the Maghreb between the 3rd-15th centuries. [ABSTRACT FROM AUTHOR]

Geochemically fingerprinted widespread tephra layers serve as excellent marker horizons which can directly link and synchronize disparate sedimentary archives and be used for dating various deposits related to climate shifts, faulting events, tsunami, and human occupation. In addition, tephras represent records of explosive volcanic activity and permit assessment of regional ashfall hazard. In this paper we report a detailed Holocene tephrochronological model developed for the Kamchatsky Peninsula region of eastern Kamchatka (NW Pacific) based on ∼2800 new electron microprobe analyses of single glass shards from tephra samples collected in the area as well as on previously published data. Tephra ages are modeled based on a compilation of 223 14 C dates, including published dates for Shiveluch proximal tephra sequence and regional marker tephras; new AMS 14 C dates; and modeled calibrated ages from the Krutoberegovo key site. The main source volcanoes for tephra in the region are Shiveluch and Kliuchevskoi located 60–100 km to the west. In addition, local tephra sequences contain two tephras from the Plosky volcanic massif and three regional marker tephras from Ksudach and Avachinsky volcanoes located in the Eastern volcanic front of Kamchatka. This tephrochronological framework contributes to the combined history of environmental change, tectonic events, and volcanic impact in the study area and farther afield. This study is another step in the construction of the Kamchatka-wide Holocene tephrochronological framework under the same methodological umbrella. Our dataset provides a research reference for tephra and cryptotephra studies in the northwest Pacific, the Bering Sea, and North America. [ABSTRACT FROM AUTHOR]

Retreat of the Antarctic ice sheets since the Last Glacial Maximum (LGM) contributed to sea-level rise, but the location, amount, and timing of ice mass loss has been controversial. This paper presents new 10 Be exposure ages from glacially transported erratics which record post LGM retreat of grounded ice in the western Ross Sea. Ice elevation in southern McMurdo Sound was ≥520 m above present day sea level on the eastern side of Mount Discovery during the LGM, and the onset of major deglaciation in the region was after 14 ka. The ice surface lowered from ∼520 to 234 m above present day sea level between 14.0 ka and 10.3 ka and from 234 m to ∼30 m between 10.3 ka and 7.4 ka. This late-glacial and Holocene deglaciation chronology from southern McMurdo Sound is consistent with other records on the margins of the Ross Embayment, and implies that the western margins of the Ross Sea Ice Sheet (RSIS) experienced most mass loss during the early to middle Holocene. These 10 Be exposure ages coupled with sediment provenance define a two-stage ice flow scenario for McMurdo Sound subdividing differing reconstructions into an early and late phase. Prior to Termination I, an expanded Koettlitz Glacier flowed north and northeast between Brown Peninsula and Mount Discovery and coalesced with northward flowing ice fed from the Skelton and Mulock Glaciers. Thinning and retreat of the Koettlitz Glacier and perhaps other outlet glaciers flowing through the Royal Society Range allowed ice grounded in the Ross Sea to flow westward and northward, north of Brown Peninsula. Grounding-line recession in the Ross Sea during the late-glacial and Holocene was likely driven by Southern Ocean warming and sea-level rise from the retreat of the Northern Hemisphere ice sheets and the outer margins of the Antarctic ice sheets. [ABSTRACT FROM AUTHOR]

Abstract: The paper reviews previously published and presents new data on the Darhad Basin, Mongolia, which is a key locality for reconstruction of Quaternary glaciation and environmental changes in northern Central Asia. The previously published data include those obtained in the 20th century by Soviet geological surveys and academic researches of the Darhad Basin, which are, as a rule, not accessible for an international reader, and those obtained by several international teams during the last decade. The new results include geomorphologic, sedimentological and geochronological data obtained prior to and within the International Darhad Drilling Project (DDP-2010). These data show that the Darhad sedimentary sequence has been formed since the Pliocene and represents a detailed archive of environmental changes due to a high content of lacustrine beds. Lakes formed several times in the Darhad Basin by basaltic, glacial and sedimentary dams, which blocked the water outlet of the basin. Of special interest in this paper are the late Pleistocene damming events, which are well-documented in the sediments and landforms, however, their chronology is still obscure. There have been two stages of deep lake. The first lake was dammed by a glacier during late MIS 5 (Krivonogov et al., 2005) or, alternatively, during early to middle MIS 3 (Gillespie et al., 2008a). The second damming, glacial or sedimentary, formed another deep lake during MIS 4 or MIS 2. The level of the lake was greatly variable up to its complete disappearance. Our new data from the DDP10-3 and DN-1 boreholes and from the Hodon outcrop illustrate the Holocene history of the paleolake, which was dammed by the sediments and was kept at low levels. We propose a first sedimentation model for the Holocene part of the lacustrine sedimentary sequence. The lake was minimal or disappeared at ca 12–9.6 and after 4.5 ka cal. BP, relatively deep at 9.6–7.1 and 6.4–4.5 ka cal. BP and shallow at 7.1–6.4 ka cal. BP. Conclusively, we highlighted solved and unsolved geological problems of the Darhad Basin, the most important of which are our recognized stages of the paleolake development (solved) and the detailed chronology and environments of the lacustrine and glacial events (unsolved). [Copyright &y& Elsevier]

The African continent is characterised by a wide range of hydroclimate regimes, ranging from humid equatorial West Africa to the arid deserts in the northern and southern subtropics. The livelihoods of much of its population are also vulnerable to future climate change, mainly through variability in rainfall affecting water resource availability. A growing number of data sources indicate that such hydroclimatic variability is an intrinsic component of Africa's natural environment. This paper, co-authored by members of the PAGES Africa 2k Working Group, presents an extensive assessment and discussion of proxy, historical and instrumental evidence for hydroclimatic variability across the African continent, spanning the last two millennia. While the African palaeoenvironmental record is characterised by spatially disjunctive datasets, with often less-than-optimal temporal resolution and chronological control, the available evidence allows the assessment of prominent spatial patterns of palaeomoisture variability through time. In this study, we focus sequentially on data for six major time windows: the first millennium CE, the Medieval Climate Anomaly (900–1250 CE), the Little Ice Age (1250–1750 CE), the end of the LIA (1750–1850 CE), the Early Modern Period (1850–1950), and the period of recent warming (1950 onwards). This results in a continent-wide synthesis of regional moisture-balance trends through history, allowing consideration of possible driving mechanisms, and suggestions for future research. [ABSTRACT FROM AUTHOR]

We review the scientific efforts over the last decades to reconstruct erosion from continuous alpine lake sediment records. We focused both on methodological issues, showing the growing importance of non-destructive high resolution approaches (XRF core-scanner) as well as progresses in the understanding of processes leading to the creation of an “erosion signal” in lakes. We distinguish “continuous records” from “event-records”. Both provide complementary information but need to be studied with different approaches. Continuous regionally-relevant records proved to be particularly pertinent to document regional erosion patterns throughout the Holocene, in particular applying the source to sink approach. Event-based approaches demonstrated and took advantage of the strong non-linearity of sediment transport in high altitude catchment areas. This led to flood frequency and intensity reconstructions, highlighting the influence of climate change upon flood dynamics in the mountain. The combination of different record types, both in terms of location (high vs. low elevation), sedimentology (high vs. low terrigenous contribution) and significance (local vs. regional) is one of the main outputs of this paper. It allows the establishment of comprehensive histories of NW French Alps erosion, but also and consequently, soil dynamics and hydrological patterns throughout the Holocene. We also discuss the influence of glacier dynamics, one of the major agents of erosion in the Alps. A major feature is the growing human influence upon erosion at a local scale since at least the middle of the Bronze Age (3500 cal. BP). However and according to the regional record from Lake Bourget, only few periods of rising erosion at local scales generated a regional record that can be discriminated from wetter climatic periods. Among them, the period between 200 BCE and 400 AD appeared to be marked by a generalised rise in human-triggered erosion at local scales in the northern French Alps. This review highlights the importance of modern high-resolution and interdisciplinary studies of lake sediments, in order to better understand the complex relationships between humans, climate and the Earth system in general. We strongly argue that regional integration of data is now required to move a step further. Such an integration is easier with cost- and time-effective methods as well as after a better definition of approaches and their limits. This should lead to a stronger collaboration between paleo-data producers and modellers in the near future. [ABSTRACT FROM AUTHOR]

This paper presents a quantitative vegetation reconstruction, based on a biomization procedure, of two mountain sites in the west (Bambili; 5°56′ N, 10°14′ E, 2273 m) and east (Rusaka; 3°26′ S, 29°37′ E, 2070 m) Congo basin in equatorial Africa during the last 18,000 years. These reconstructions clarify the response of vegetation to changes in climate, atmospheric pressure, and CO 2 concentrations. Two major events characterize the biome changes at both sites: the post-glacial development of all forest biomes ca. 14,500 years ago and their rapid collapse during the last millennium. The rates of forest development between the biomes are different; a progressive expansion of lowland biomes and an abrupt expansion of montane biomes. The trends of pollen diagrams and biome affinity scores are not always consistent in some periods such as the Younger Dryas interval and end of the Holocene Humid Period, because the biomization method is not a simple summarization of the pollen data, but also takes biodiversity into consideration. Our sensitivity experiment and inverse-vegetation modeling approach show that changes in atmospheric CO 2 concentration unequally influence vegetation in different local environments. The study also suggests that the biome changes prior to the Holocene result from both changes in the atmospheric CO 2 concentration and climate. The development of warm-mixed forest from xerophtic vegetation results from increases in atmospheric CO 2 concentration and near-surface air temperature. Difference in local dryness results in the different biome distributions, with more forest-type biomes at Bambili and more grass/shrub-type biomes at Rusaka. [ABSTRACT FROM AUTHOR]

This synthesis paper summarizes published proxy climate evidence showing the spatial and temporal pattern of climate change through the Holocene in Arctic Canada and Greenland. Our synthesis includes 47 records from a recently published database of highly resolved Holocene paleoclimate time series from the Arctic (Sundqvist et al., 2014). We analyze the temperature histories represented by the database and compare them with paleoclimate and environmental information from 54 additional published records, mostly from datasets that did not fit the selection criteria for the Arctic Holocene database. Combined, we review evidence from a variety of proxy archives including glaciers (ice cores and glacial geomorphology), lake sediments, peat sequences, and coastal and deep-marine sediments. The temperature-sensitive records indicate more consistent and earlier Holocene warmth in the north and east, and a more diffuse and later Holocene thermal maximum in the south and west. Principal components analysis reveals two dominant Holocene trends, one with early Holocene warmth followed by cooling in the middle Holocene, the other with a broader period of warmth in the middle Holocene followed by cooling in the late Holocene. The temperature decrease from the warmest to the coolest portions of the Holocene is 3.0 ± 1.0 °C on average (n = 11 sites). The Greenland Ice Sheet retracted to its minimum extent between 5 and 3 ka, consistent with many sites from around Greenland depicting a switch from warm to cool conditions around that time. The spatial pattern of temperature change through the Holocene was likely driven by the decrease in northern latitude summer insolation through the Holocene, the varied influence of waning ice sheets in the early Holocene, and the variable influx of Atlantic Water into the study region. [ABSTRACT FROM AUTHOR]

The Aleutian Arc-Alaska Peninsula and Wrangell volcanic field are the main source areas for tephra deposits found across Alaska and northern Canada, and increasingly, tephra from these eruptions have been found further afield in North America, Greenland, and Europe. However, there have been no broad scale reviews of the Late Pleistocene and Holocene tephrostratigraphy for this region since the 1980s, and this lack of data is hindering progress in identifying these tephra both locally and regionally. To address this gap and the variable quality of associated geochemical and chronological data, we undertake a detailed review of the latest Pleistocene to Holocene tephra found in interior Alaska and Yukon. This paper discusses nineteen tephra that have distributions beyond southwest Alaska and that have the potential to become, or already are, important regional markers. This includes three ‘modern’ events from the 20th century, ten with limited data availability but potentially broad distributions, and six that are widely reported in interior Alaska and Yukon. Each tephra is assessed in terms of chronology, geochemistry and distribution, with new Bayesian age estimates and geochemical data when possible. This includes new major-element geochemical data for Crater Peak 1992, Redoubt 1989–90, and two andesitic tephra from St Michael Island (Tephra D), as well as revised age estimates for Dawson tephra, Oshetna, Hayes set H, Aniakchak CFE II, and the White River Ashes, northern and eastern lobes. [ABSTRACT FROM AUTHOR]

High-resolution Os isotope stratigraphy can aid in reconstructing Pleistocene ice sheet fluctuation and elucidating the role of local and regional weathering fluxes on the marine Os residence time. This paper presents new Os isotope data from ocean cores adjacent to the West Greenland ice sheet that have excellent chronological controls. Cores MSM-520 and DA00-06 represent distal to proximal sites adjacent to two West Greenland ice streams. Core MSM-520 has a steadily decreasing Os signal over the last 10 kyr ( 187 Os/ 188 Os = 1.35–0.81). In contrast, Os isotopes from core DA00-06 (proximal to the calving front of Jakobshavn Isbræ) highlight four stages of ice stream retreat and advance over the past 10 kyr ( 187 Os/ 188 Os = 2.31; 1.68; 2.09; 1.47). Our high-resolution chemostratigraphic records provide vital benchmarks for ice-sheet modelers as we attempt to better constrain the future response of major ice sheets to climate change. Variations in Os isotope composition from sediment and macro-algae (seaweed) sourced from regional and global settings serve to emphasize the overwhelming effect weathering sources have on seawater Os isotope composition. Further, these findings demonstrate that the residence time of Os is shorter than previous estimates of ∼10 4 yr. [ABSTRACT FROM AUTHOR]

Active periglacial processes are currently marginal in the Iberian Peninsula, spatially limited to the highest mountain ranges. However, a wide variety of periglacial deposits and landforms are distributed in low and mid-altitude environments, which shows evidence of past periods of enhanced periglacial activity. The purpose of this paper is to summarize the present knowledge of past periglacial activity in the Iberian Peninsula. The chronological framework takes four main stages into account: the last glaciation, deglaciation, Holocene and present-day processes. This study focuses on the highest massifs (Pyrenees, Cantabrian Range, NW ranges, Central Range, Iberian Range, Sierra Nevada) as well as other lower elevation environments, namely the central Iberian Meseta. During the last glaciation the periglacial belt extended to much lower altitudes than today, reaching current sea level in the NW corner of the Iberian Peninsula. A wide range of geomorphological landforms and sedimentary records is indicative of very active periglacial processes during that phase, in some cases related to permafrost conditions (i.e., block streams, rock glaciers). Most of the inactive landforms and deposits in low and mid-elevations in Iberia are also related to this phase. The massive deglaciation of the Iberian massifs was caused by a gradual increase in temperatures. The deglaciation phase was only interrupted by a short period with colder conditions (the Younger Dryas) that reactivated periglacial processes in the formerly glaciated cirques of the highest lands, specifically with the widespread development of rock glaciers. During the Holocene, periglacial processes have been only active in the highest ranges, shifting in altitude according to temperature regimes and moisture conditions. The Little Ice Age saw the reactivation of periglacial activity in lower elevations than today. Currently, periglacial processes are only active in elevations exceeding 2500 m in the southern ranges and above 2000–2200 m in the northern massifs, higher in Sierra Nevada, in the south of Iberian Peninsula. [ABSTRACT FROM AUTHOR]

Turbidity current is one of the most important mechanisms for rapid transportation of terrigenous sediments from the continental margin to the deep sea. Although extensive work on turbidite systems has been carried out globally, the Tanzanian margin, off East Africa, is poorly understood. This paper will therefore use a well-dated high-resolution marine core (GeoB12624-1), obtained during RV Meteor Cruise M75/2, from the upper Tanzanian continental slope, offshore the Rufiji River delta, to demonstrate which environmental parameters, e.g., climate versus sea level, control the temporal distribution of the turbidite deposits during the last deglaciation and the Holocene. Results show that the turbidite deposits are composed of coarser-grained sediments with normally graded bedding. The thickness, mean grain size and frequency of the turbidite beds were estimated to detect turbidity current activity since the Last Glacial Maximum (LGM). A total of 12 turbidite beds (TI-T12) was recognized and divided into three intervals, based on the presence and intensity of the turbidite deposits. (I) a glacial sea-level lowstand (LGM and Heinrich Stadial 1; 19.3–14.6 ka): suppressed turbidity current activity due to arid conditions in the hinterland and sea-level lowstand. (II) A deglacial sea-level rise period (Bølling-Allerød interval to the early Holocene; 14.6–8 ka): turbidity current activity started to be strengthened during the Bølling-Allerød warming interval (T1), followed by a first increase in turbidite frequency, thickness and mean grain-size during the Younger Dryas (T2–T4) and a second increase during the early Holocene (T5–T10). (III) An interglacial sea-level highstand period (mid-to late Holocene; 8–2.5 ka): turbidity current activity diminished from the mid- (T11, T12) to late Holocene. This temporal distribution of turbidite deposits indicates that turbidity currents were most active during the last sea-level rise, synchronous with more humid climate in the hinterland, than during a sea-level lowstand (e.g., LGM) when climate was more arid. Thus, we propose that it is the climate conditions in the hinterland that form the primary controlling factor for turbidity current activity of Tanzanian slope. The remobilization of lowstand sediments on the Tanzanian continental margin during a sea-level rise, combined with shedding sediments towards the study area from the main canyon/channel, also plays a role in supplying new sediments to the turbidite system. These new data demonstrate that, in specific continental margin, high fluvial discharge will promote sediment transfer along the shelf and slope even during sea-level rise and highstand. [ABSTRACT FROM AUTHOR]

The coupling of lake dynamics with catchment biogeochemistry is considered the key element controlling primary production in mountain lakes at time scales of a few decades to millennia, yet little is known on the impacts of the morphometry of lakes throughout their ontogeny. As Lake Chungará (Central Andean Altiplano, northern Chile) experienced long-term lake-level fluctuations that strongly modified its area:volume ratio, it is an ideal system for exploring the relative roles that long-term climatic shifts and lake morphometry play on biosiliceous lacustrine productivity. In this paper, we review previous data on the percent contents of total organic carbon, total inorganic carbon, total nitrogen, total biogenic silica, isotopic composition of organic matter, carbonates, and diatom frustules, as well as data on the abundance of the chlorophycean Botryococcus braunii in this lake for the period 12,400–1300 cal yr BP. We also include new data on organic carbon and biogenic silica mass accumulation rates and the diatom assemblage composition of an offshore core dated using 14 C and U/Th. Biosiliceous productivity in Lake Chungará was influenced by shifts in allochthonous nutrient inputs related to variability in precipitation. Humid phases dated at approx. 12,400 to 10,000 and 9600 to 7400 cal yr BP coincide with periods of elevated productivity, whereas decreases in productivity were recorded during arid phases dated at approx. 10,000 to 9600 and 7400 to 3550 cal yr BP (Andean mid-Holocene Aridity Period). However, morphometry-related in–lake controls led to a lack of a linear response of productivity to precipitation variability. During the late Glacial to early Holocene, lowstands facilitated complete water column mixing, prompting episodic massive blooms of a large centric diatom, Cyclostephanos cf. andinus . Thus, moderate productivity could be maintained, regardless of aridity, by this phenomenon of morphometric eutrophy during the early history of the lake. The subsequent net increase in lake level introduced modifications in the area of the epilimnion sediments versus the total volume of the epilimnion, preventing complete overturn. Surpassing a certain depth threshold at approx. 8300 cal yr BP caused cessation of the morphometric eutrophy conditions associated with Cyclostephanos cf. andinus superblooms. After 7300 cal yr BP, the lake experienced a decrease in biosiliceous productivity and a change of state that involved a stronger dependence on precipitation variability, with a lesser contribution of diatoms to the total primary productivity. Our results show that the interpretation of lacustrine paleoproductivity records as paleoclimatic archives needs to take into account the effects of changes in the epilimnion sediment area to epilimnion volume ratio in association with lake ontogeny. [ABSTRACT FROM AUTHOR]

The Coast Mountains flank the Pacific Ocean in western British Columbia, Canada. Subdivided into the southern Pacific Ranges, central Kitimat Ranges and northern Boundary Ranges, the majority of large glaciers and icefields are located in the Boundary and Pacific ranges. Prior descriptions of the Holocene glacial history of this region indicate the Holocene was characterized by repeated episodes of ice expansion and retreat. Recent site-specific investigations augment our understanding of the regional character and duration of these events. In this paper, previously reported and new radiocarbon evidence is integrated to provide an updated regional assessment. The earliest evidence of glacier expansion in the Coast Mountains comes from the Boundary Ranges at 8.9 and 7.8 ka and in the Pacific Ranges at 8.5–8.2 ka, with the latter advance corresponding to an interval of rapid, global climate deterioration. Although generally warm and dry climates from 7.3 to 5.3 ka likely limited the size of glaciers in the region, there is radiocarbon evidence for advances over the interval from 7.3 to 6.0 and at 5.4–5.3 ka in the Pacific Ranges. Following these advances, glaciers in the Pacific Ranges expanded down valley at 4.8–4.6, 4.4–4.0, 3.5–2.6, 1.4–1.2, and 0.8–0.4 ka, while glaciers in Boundary Ranges were advancing at 4.1–4.0, 3.7–3.4, 3.1–2.8, 2.3, 1.7–1.1, and 0.8–0.4 ka. After 0.4 ka, it appears that most glaciers in the Coast Mountains continued to expand to attain their maximum Holocene extents by the early 18th to late 19th centuries. This enhanced record of Holocene glacier activity highlights the temporal synchrony in the Coast Mountains. Individual expansion events in the mid-to late Holocene broadly correspond to intervals of regional glacier activity reported in the Canadian Rocky Mountains, in Alaska, and on high-elevation volcanic peaks in Washington State. [ABSTRACT FROM AUTHOR]

Few records of late Quaternary relative sea level (RSL) are available for the Pacific coast of North America south of San Francisco Bay, a region where RSL data would be particularly useful for constraining vertical rates of tectonic motion. This paper provides the first regional, uplift-corrected late Quaternary RSL history for southern California derived from a compilation of 132 previously published and unpublished radiocarbon ages from nearshore, estuarine, and freshwater deposits in sediment cores from coastal southern California. We also provide a local, uplift-corrected RSL history for Monterey Bay, central California, generated from 48 radiocarbon ages from Elkhorn Slough and surrounding environments. Our resulting compilations show rapid sea-level rise from 15 ka which begins to decelerate to present mean sea level (PMSL) between 6 and 8 ka. Late Holocene (<4 ka) sea-level rise averaged 0.8 ± 0.3 mm a −1 in southern California and 1.3 ± 0.19 mm a −1 along Monterey Bay in central California. Both rates of late Holocene RSL rise calculated are lower than recent RSL rates from southern California (∼1.61 ± 0.34 to 2.4 ± 1.04 mm a −1 ) and Monterey Bay (1.49 ± 0.95 mm a −1 ), derived from uplift-corrected, 20th century tide gauge data. This new RSL data fills geographical gaps in relative sea-level histories, as well as provides important datums for local tectonic processes. [ABSTRACT FROM AUTHOR]

South Africa's southwestern Cape occupies a critical transition zone between Southern Hemisphere temperate (winter) and tropical (summer) moisture-bearing systems. In the recent geological past, it has been proposed that the relative influence of these systems may have changed substantially, but little reliable evidence regarding regional hydroclimates and rainfall seasonality exists to refine or substantiate the understanding of long-term dynamics. In this paper we present a mid-to late Holocene multi-proxy record of environmental change from a rock hyrax midden from Katbakkies Pass, located along the modern boundary between the winter and summer rainfall zones. Derived from stable carbon and nitrogen isotopes, fossil pollen and microcharcoal, these data provide a high resolution record of changes in humidity, and insight into changes in rainfall seasonality. Whereas previous work concluded that the site had generally experienced only subtle environmental change during the Holocene, our records indicate that significant, abrupt changes have occurred in the region over the last 7000 years. Contrary to expectations based on the site's location, these data indicate that the primary determinant of changes in humidity is summer rather than winter rainfall variability, and its influence on drought season intensity and/or length. These findings are consistent with independent records of upwelling along the southern and western coasts, which indicate that periods of increased humidity are related to increased tropical easterly flow. This substantially refines our understanding of the nature of temperate and tropical circulation system dynamics in SW Africa, and how changes in their relative dominance have impacted regional environments during the Holocene. [ABSTRACT FROM AUTHOR]

Records of past climate variability and associated vegetation response exist in various regions throughout Central and Eastern Europe (CEE). To date, there has been no coherent synthesis of the existing palaeo-records. During an INTIMATE meeting (Cluj Napoca, Romania) focused on identifying CEE paleo-records, it was decided to address this gap by presenting the palaeo-community with a compilation of high-quality climatic and vegetation records for the past 60–8 ka. The compilation should also serve as a reference point for the use in the modelling community working towards the INTIMATE project goals, and in data-model inter-comparison studies. This paper is therefore a compilation of up to date, best available quantitative and semi-quantitative records of past climate and biotic response from CEE covering this period. It first presents the proxy and archive used. Speleothems and loess mainly provide the evidences available for the 60–20 ka interval, whereas pollen records provide the main source of information for the Lateglacial and Holocene. It then examines the temporal and spatial patterns of climate variability inferred from different proxies, the temporal and spatial magnitude of the vegetation responses inferred from pollen records and highlights differences and similarities between proxies and sub-regions and the possible mechanisms behind this variability. Finally, it identifies weakness in the proxies and archives and their geographical distribution. This exercise also provides an opportunity to reflect on the status of research in the area and to identify future critical areas and subjects of research. [ABSTRACT FROM AUTHOR]

Steppe and grassland ecosystems constitute important biomes that are influenced by multiple factors such as climate, human activity, and fire. Yet how these factors have influenced the plant composition of these biomes through time continues to be understudied. This paper investigates how these mechanisms have transformed the steppe landscape recorded at the mire site of Shenkani, Armenia. This highland site, located in the South Caucasus, has a long human history of permanent settlements near the core site starting at 5500 cal. BP. A variety of biological and geochemical proxies, including pollen, non-pollen palynomorphs, macro-charcoal, 14C age model, X-ray fluorescence, loss-of-ignition, magnetic susceptibility, and a quantitative climate reconstruction inferred from pollen, are utilized in this paper. We find that this area has remained a steppe with small stands of trees throughout the duration of the Holocene. Changes in steppe plant composition primarily occur between semi-desert steppes (Chenopodiaceae), grassland steppes (or Poaceae dominated meadow-steppes), and mixed steppes with forest patches. In this record, two phases of local grassland expansion occurred between 9500 and 7000 cal. BP and 2500–1000 cal. BP, which covaried with local fire events. These grassland steppes were sustained until tree encroachment led to a more mixed steppe landscape around 7000 cal. BP and again at 1000 cal. BP. Climate, primarily precipitation, is the main driver of this persistent steppe landscape and the plant compositional shifts within it. However, fire and human activities contributed to steppe maintenance. • A 10,240 year-old sequence from Shenkani, Armenia documents a persistent Holocene steppe. • Changes in steppe plant composition occur between semi-desert, grassland, and mixed steppes with forest patches. • Poaceae dominated grasslands covary with fires that limit tree and shrub encroachment. • The mid- to late Holocene transition is characterized by drops in Betula and declines in distant arboreal pollen. [ABSTRACT FROM AUTHOR]

The importance of climate change, specifically drought, across the Maya region in the northern Neotropics, remains a topic of lively debate. Part of this discussion hinges on the coherency of response to climatic variability across different archives and proxies. In this paper we present a 6600-year palaeolimnological record from Yaal Chac, a carbonate lake (known locally as a cenote) in the northern lowlands of the Yucatan Peninsula, < 2 km from the location of the previously published Aguada X'Caamal record. The Yaal Chac sequence has been analysed for loss-on-ignition (LOI), stable isotopes (δ18O, δ13C) and elemental analysis using μXRF, complemented by some mineralogical, charcoal and pigment data. Mid Holocene sediments, predating evidence of human impact, are carbonate dominated and finely laminated. δ18O values are positive (>2‰), but show no covariation with δ13C. A major transition occurs at ca. 4360 cal yr BP, with a change to generally more organic sediments and increased variability in all proxies. Although direct evidence for anthropogenic activity in the Yaal Chac catchment is limited, it seems feasible that human impact was affecting the system. Comparison with other records from the Northern Maya lowlands and the wider region shows little coherence in the mid Holocene, when Yaal Chac seems to have been quite stable, but possibly responsive to increased climatic seasonality, driving the production of seasonal laminae. In the late Holocene, when the climate was generally more variable, there is more coherence between Yaal Chac and other regional records, including the so called Pan Caribbean Dry Period (3500–2500 cal yr BP) and the droughts of the late Pre-Classic period (1800–1600 cal yr BP). The Yaal Chac record shows no evidence of drought at the time of either the Maya 'hiatus' or the Maya 'collapse' of the Terminal Classic, but does record drying from the 14th to 19th centuries CE, in keeping with other proxy and historical records. This new record from Yaal Chac highlights the spatial variability of responses to climate forcings and the importance of recognising individual system sensitivity. • A new 6600 year palaeolimnological record from Yaal Chac in the northern Maya lowlands. • Finely laminated, carbonate dominated sediments until ca. 4360 cal yr BP, then major transition. • Mid Holocene record seems to reflect enhanced seasonality in an otherwise stable climatic regime. • Late Holocene increased climatic variability and more regional coherence. • No evidence for severe drought at the time of the Maya 'hiatus' or the Maya 'collapse'. [ABSTRACT FROM AUTHOR]

Abstract: Recent sampling of deglacial and postglacial raised marine sediments across Melville and Eglinton islands in the western Canadian High Arctic yielded over 200 new radiocarbon dates on molluscs, driftwood and other organic materials. From this database, eight relative sea-level curves and an isobase map for the 9.5 cal ka BP shoreline were constructed. The forms, chronology and pattern of the relative sea-level curves across the study area reflect the complex glacial history of this region, including the asynchronous retreat of the formerly coalescent Laurentide and Innuitian Ice Sheets. Zone I relative sea-level curves, which show continuous emergence to present, were observed in areas closer to greater Last Glacial Maximum ice sheet loading; at more distal sites, transitional Zone I/II curves display emergence followed by submergence in the mid- to late-Holocene (still ongoing) related to forebulge migration and collapse. An independent record of late Holocene submergence is provided by radiocarbon-dated driftwood, which is accumulating at modern sea level due to re-deposition during transgression. Geomorphic evidence of submergence at the modern coastline is widespread but does not distinguish areas that experienced a late Holocene lowstand and subsequent transgression from those that are currently at their lowstand. Of special interest are the relative sea-level histories of two areas that experienced earlier deglaciation by the Laurentide Ice Sheet, while remaining in the peripheral depression of the more stable and adjacent Innuitian Ice Sheet. The flat-topped relative sea-level curves from these sites appear to record unusually slow rates of glacioisostatic emergence for ∼1500 years immediately following deglaciation. The relative sea-level data presented in this paper provide important comparisons for sea level models, which have been shown to fit poorly with previously published data from this region. [Copyright &y& Elsevier]

Abstract: South Africa's southern coastal margin is recognised as being a highly dynamic climatic region that plays a critical role in both regional and global atmospheric and oceanic circulation dynamics. Our understanding of the past dynamics of this system, however, has been limited by the number and nature of datasets available that can be used to infer changes in key climatic parameters in the region. In this paper we present new high resolution δ13C and δ15N data from two independently dated rock hyrax (Procavia capensis) middens from Seweweekspoort in South Africa's Groot Swartberg mountains. These data provide information regarding both past vegetation and hydroclimatic change, and allow a regional integration of available data that explore the long-term dynamics of mid-latitude circulation systems in the African sector of the Southern Hemisphere. Combined, a negative relationship is apparent between temperature and humidity in this area of the southern Cape, and these changes can for the first time be clearly linked to variations in Antarctic sea-ice extent and shifts in the southern westerly storm track. This dynamic is particularly evident between 5 and 7 cal kBP, when a reduction in sea-ice extent and a southward shift of the westerlies are manifested regionally by increased temperatures and a phase of marked aridity. [Copyright &y& Elsevier]

Abstract: During the Holocene, delta evolution has been collectively mediated by relative sea-level changes, continental hydrology and human impacts. In this paper, we present a strontium isotope record from the Maryut lagoon (northwestern Nile delta) to quantify the interplay between relative sea-level variations and Nile flow changes during the past 7500 years. 87Sr/86Sr stratigraphy allows five hydrological stages to be defined. (1) The marine transgression of the area is dated to ∼7.5 ka cal. BP, with a clear marine 87Sr/86Sr signature (0.70905–0.7091). (2) Between ∼7 and ∼5.5 ka, in the context of the so-called African Humid Period (AHP), freshwater inputs became progressively predominant in the Maryut's hydrology. Deceleration of sea-level rise coupled with high Nile discharge induced coastal progradation which led to the progressive closure of the Maryut lagoon. (3) Between ∼5.5 and ∼3.8 ka, the end of the AHP is translated by a progressive hydrological shift from a Nile-dominated to a marine-dominated lagoon (87Sr/86Sr shifts from 0.70865 to 0.7088 to 0.70905–0.70915). (4) From ∼2.8 to ∼1.7 ka, 87Sr/86Sr ratios shift towards lower values (0.7084). Although this change is not precisely resolved because of a hiatus in the Maryut's sedimentary record, the 87Sr/86Sr transition from sea-like to Nile-dominated values is attributed to irrigation practices since the early Ptolemaic period (i.e. since ∼2.3 ka), including the Alexandria canal which played a key role in isolating the Maryut from the Mediterranean sea. (5) The final phase of the record covers the period between ∼1.7 and ∼0.2 ka. 87Sr/86Sr ratios indicate high freshwater inputs (from 0.7080 to 0.7085), except between 1.2 and 1.1 to ∼0.7 ka, when a Maryut lowstand and seawater intrusion are attested. In modern times, the Nile's coastal lagoons have been increasingly supplied by freshwater linked to the diversion of waters from the two Nile branches into the irrigation system. It is suggested that this process began in early Antiquity and has engendered a reduction in the number of Nile branches from seven in ancient times to just two at present. [Copyright &y& Elsevier]

The present paper provides new insights into the climatic and anthropic factors that influenced a 6000-year coastal evolution in northwestern Corsica, the third largest island of the western Mediterranean. Pollen, microcharcoal, sedimentary and geochemical analyses were carried out on a core drilled in the Crovani coastal wetland to reconstruct the regional drivers of landscape change. We show that anthropogenic and climate-induced fires favoured the development of Mediterranean maquis, dominated by Erica and Quercus ilex , from ca. 6000 to 3350 cal. BP. A change in arboreal vegetation triggered a short but intense sediment input in the Crovani pond between ca. 3350 and 3200 cal. BP. This is consistent with a coeval process of runoff recorded in several coastal sites of western Corsica and related to an arid climate change occurred in many sites of the western Mediterranean around 3200 years ago. We provide evidence of agriculture during the Late Neolithic from ca. 3900 BC, which is much earlier than any archaeological evidence previously available in this area of Corsica, followed by a progressive decline of arable farming practices. Human impact has been responsible for a degradation of the maquis only from approximately 3000 cal. BP, and it intensified in Roman times, when the area experienced the first phase of galena exploitation from the Argentella mines. Over the last 500 years, the present work evidences a major development of Castanea related to cultivation during the Genoese administration of Corsica. Our findings suggest that solar activity and the North Atlantic Oscillation had an influence on centennial-scale forest cover variations during the last 6000 years. • A new palynological, sedimentological and geochemical study is presented from a coastal wetland of Corsica. • The high-resolution 6000-year pollen record shows an unprecedented long persistence of Erica and Quercus ilex maquis. • Human activities developed especially during the Late and Final Neolithic and the last 1000 years. • Evidence of agriculture predates any Neolithic archaeological findings in this region. • The 4.2 ka event, Homeric Minimum, and Little Ice Age are not associated with forest declines. [ABSTRACT FROM AUTHOR]

Our aim with this paper is to provide insight into the landscape dynamics of the Cantabrian region (northern Iberian Peninsula) from the Last Glacial Period to the present. We present a multiproxy approach performed in a sedimentary record from La Molina peat bog, located at 484 m a. s. l. in Puente Viesgo, Cantabria (Latitude: 43.26° N; Longitude: 3.97° W), that covers the last c. 17,550 years. Analyses were performed on the organic matter, pollen and sedimentary charcoals, which have been used to characterise the fire regime at a local level. The results revealed a steppe-like formation from the basis of the sequence to the Bølling-Allerød chronozone, when the spread of woody species is detected. The dry and cold conditions of the Younger Dryas caused the decrease of mesophilous taxa until the onset of the Holocene. From that point onwards, a mixed deciduous formation composed of Betula and deciduous Quercus was established in the region. Besides, a series of biomass pulses was detected during the early Holocene, probably linked to intervals of increased rainfall. Fire episodes detected at the 9.3 and the 8.2 ka events created forest openings and probably favoured the establishment of Corylus, most likely also helped by a climate shift. There was a lack of fire activity until the Neolithic, when the fire signal increased probably linked to grazing and agricultural practices and triggered deeper changes in the Cantabrian plant landscape structure. • There is no evidence of pine forests during the last 17.55 cal ka. • A steppe-like formation is revealed until the spread of Betula at 13.7 cal ka BP. • Fires triggered changes in landscape composition during the 9.3 and 8.2 ka events. • The spread of Corylus was likely helped by a climate shift and the fire activity. • Agriculture was accompanied by recurrent fire activity to create forest openings. [ABSTRACT FROM AUTHOR]

The Holocene terrestrial malacofauna of the northern shore of the Mediterranean remains poorly known. Its importance however is twofold, first to better understand the recolonization of Europe by woodland snails from different kinds of glacial refugia, secondly to bring to light the development of Mediterranean ecosystems. This paper is based on molluscan analyses of three sedimentary sequences from a catchment basin near Aix-en-Provence, all of which being representative of the most common pedo-sedimentary and malacological postglacial successions in southeastern France. A special effort has been made to establish the chronology. The results first show the lasting of temperate steppes, lasting in places all the way into the Boreal period (∼9000 cal yr BP). Less open environments appeared soon after with assemblages including thermophilic species. The Boreal period shows unstable conditions in an open and heterogeneous woodland landscape. A malacofauna indicating true woodland developed during the Older Atlantic (∼8000 cal yr BP). Dominated by "semi-forest" snails, it still contained some xerophilic ones. These assemblages lost their true woodland character between ∼7000 and ∼6500 cal yr BP due to anthropogenic influence. An increase in human activity and merchandise flow within a more open landscape caused a progressive but deep turnover of land snail communities since the Early Neolithic. It must be admitted that, during the Holocene as a whole, Mediterranean ecosystems remained heterogeneous and frequently open. The human impact is such that it is difficult to discuss the role of climate since ∼7000 cal yr BP. • Temperate steppe environments lasted, in places, until ∼9000 cal yr BP. • True open woodland snail assemblages date from the Older Atlantic at ∼8000 cal yr BP. • First clear anthropogenic impacts occur between ∼7000 and ∼6500 cal yr BP. • Anthropization is the cause of a progressive but deep renewal of land snail communities from ∼7000 cal yr BP. • The weight of human impact masks the evidence for climate events since ∼7000 cal yr BP. [ABSTRACT FROM AUTHOR]

Abstract: The vegetation of Europe has undergone substantial changes during the course of the Holocene epoch, resulting from range expansion of plants following climate amelioration, competition between taxa and disturbance through anthropogenic activities. Much of the detail of this pattern is understood from decades of pollen analytical work across Europe, and this understanding has been used to address questions relating to vegetation-climate feedback, biogeography and human impact. Recent advances in modelling the relationship between pollen and vegetation now make it possible to transform pollen proportions into estimates of vegetation cover at both regional and local spatial scales, using the Landscape Reconstruction Algorithm (LRA), i.e. the REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) and the LOVE (LOcal VEgetation) models. This paper presents the compilation and analysis of 73 pollen stratigraphies from the British Isles, to assess the application of the LRA and describe the pattern of landscape/woodland openness (i.e. the cover of low herb and bushy vegetation) through the Holocene. The results show that multiple small sites can be used as an effective replacement for a single large site for the reconstruction of regional vegetation cover. The REVEALS vegetation estimates imply that the British Isles had a greater degree of landscape/woodland openness at the regional scale than areas on the European mainland. There is considerable spatial bias in the British Isles dataset towards wetland areas and uplands, which may explain higher estimates of landscape openness compared with Europe. Where multiple estimates of regional vegetation are available from within the same region inter-regional differences are greater than intra-regional differences, supporting the use of the REVEALS model to the estimation of regional vegetation from pollen data. [Copyright &y& Elsevier]

Abstract: In this introductory paper we summarize the history and achievements of the Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO), an interdisciplinary project embedded in the International Continental Scientific Drilling Program (ICDP). The stringent multiproxy approach adopted in this research combined with radiocarbon and luminescence dating provided the opportunity to synthesize a large body of hydrologically relevant data from Laguna Potrok Aike (southern Patagonia, Argentina). At this site, lake level was high from 51 ka until the early Holocene when the Southern Hemisphere Westerlies (SHW) were located further to the north. At 9.3 ka cal. BP the SHW moved southward and over the latitude of the study area (52°S) causing a pronounced negative water balance with a lake level decrease of more than 50 m. Two millennia later, the SHW diminished in intensity and lake level rose to a subsequent maximum during the Little Ice Age. Since the 20th century, a strengthening of the SHW increased the evaporative stress resulting in a more negative water balance. A comparison of our data with other hydrological fluctuations at a regional scale in south-eastern Patagonia, provides new insights and also calls for better chronologies and high-resolution records of climate variability. [Copyright &y& Elsevier]

Abstract: This paper applies meta-analysis techniques to a database of 401 14C-dated Holocene fluvial units in New Zealand. We use the database to produce a probability-based reconstruction of Holocene river behaviour at a national and regional scale. Records of river activity in northern (North Island) and southern (South Island) New Zealand are compared with independent hydro-climate proxy records that reflect regional, tropical and polar influences on Southern Hemisphere climate. During the Holocene, 12 multi-centennial length episodes of river activity and flooding were identified in the North Island, and in the South Island record 11 periods exceed the mean relative probability of activity. These records show that episodes of river activity have exhibited a predominantly out-of-phase relationship, suggesting the relationship between ENSO and SAM, and the relative dominance of the two modes, may be influencing Holocene river activity in New Zealand. The emerging pattern in the South Island Holocene fluvial record is one of increased river activity in response to enhanced westerly atmospheric circulation associated with a predominance of trough regime synoptic type (negative SAM-like circulation). In the North Island episodes of river activity are driven by increased meridional atmospheric circulation associated with blocking regime synoptic conditions (La Niña-like and positive SAM-like circulation). Analysis of floodplain sedimentation rates shows a rapid increase after ∼500 cal yr BP following the arrival of humans and the beginning of widespread deforestation. Regional climate complexity in New Zealand presents opportunities for palaeoclimate reconstruction, with the New Zealand fluvial 14C-database ideally placed to fill geographical gaps in the long-term hydrological record. [Copyright &y& Elsevier]