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The hyper-arid climate of Ouargla area (Northern Sahara of Algeria) is important in the field of the paleoenvironmental reconstitution. This paper investigates the importance of palaeolake sediments as significant terrestrial archives for studying Quaternary climate changes. Through morphological and mainly micromorphological investigations of the studied sites (Sabkha of Ouargla and palaeolake of Mellala), we noted the fluctuation of climate between arid and more humid conditions during Quaternary. Some pedofeatures have recorded these environmental changes. The studied calcareous crusting has a lacustrine origin when precipitations were more important. The clay coatings around the quartz grains indicate an old origin and different geochemical conditions that led to their dissolution. Lenticular gypsum crystals were formed from groundwater saturated with Ca2+andions. Calcite pseudomorphs after lenticular gypsum crystals indicate changes in local climatic parameters. Gypsum crusts can be explained by formation under wet climatic conditions in a lagoonal environment. Black and gray layers indicate evolution of organic matter at a wetter period. This paper highlights an unknown palaeolake which can be useful for the comprehension of the ecological past of the Sahara. The comparison between this palaeolake and other Saharan palaeolakes has allowed us to assign it to a probable active period between 10000 and 4000 years B.P. [ABSTRACT FROM PUBLISHER]

Abstract: Interglacials of the Quaternary Period are currently the focus of a great deal of attention within the scientific community. This is primarily because they play a vital role in distinguishing between “natural” and “human” climate change in the current interglacial and in understanding how the Holocene would evolve in the absence of anthropogenic greenhouse warming. In this respect, Marine Isotope Stage 11 (MIS 11, ca 410,000yr BP) is one of the key interglacial stages of the past 450,000yr. The pattern of insolation variability that occurs during MIS 11 matches that which occurs in the Holocene more closely than in any other warm stage of the past half a million years. In addition there is now an extensive range of evidence for MIS 11 palaeoclimates and palaeoenvironments from marine, ice core, lacustrine and terrestrial sequences. The aim of this paper is to provide a comprehensive review of the current state of our understanding of MIS 11. This is the first paper to provide a detailed review of MIS 11 that incorporates the wide range of marine, ice core, long lacustrine and terrestrial records that have been generated over the last ten years since the last major overview. Crucially, it is the first review of MIS 11 that incorporates a detailed synthesis of the high-resolution terrestrial sequences of western and central Europe. This paper, therefore, provides a holistic integration of a diverse range of proxies and archives to provide a detailed understanding of the expression of MIS 11 in the Earth system. In particular the review focuses on: (1) the climatic background of MIS 11, (2) the robustness of the identification of MIS 11 in a diverse range of sequences, (3) the climatic structure of MIS 11, (4) the magnitude of warmth that occurred in this warm stage, (5) MIS 11 sea level magnitude and variability, (6) the duration of MIS 11, (7) evidence for abrupt climatic events within the interglacial of MIS 11 and (8) precipitation patterns and trends during this interglacial. The paper concludes by considering how useful MIS 11 is as an analogue for Holocene climates and compares it with other proposed analogues, such as MIS 19, with particular reference to the “early anthropogenic” hypothesis. [Copyright &y& Elsevier]

Abstract: High-resolution environmental proxy data from the extratropical North Atlantic prior to the instrumental era are of critical importance to decipher processes and mechanisms of global change. In this regard, shells of the extremely long-lived bivalve mollusc, Arctica islandica (Linnaeus, 1767), have gained particular attention during the last decade because they serve as reliable, subseasonally resolved multi-proxy archives of environmental variability in that very region. With a lifespan of more than 500years, A. islandica is the longest-lived solitary animal. Its shell grows periodically throughout life and contains distinct annual and daily growth increments. These growth patterns function as a calendar that can be used to place each shell portion into a precise temporal context. Furthermore, changing environmental conditions are encoded in the shells in the form of variable increment widths and geochemical properties. By means of cross-dating, growth increment width chronologies from different specimens can be combined into much longer time-series, so-called composite or master chronologies, covering centuries to millennia and many generations of bivalves. The present paper provides a comprehensive review of research on this species with a special focus on long-term climate and environmental reconstructions using isotopes, trace and minor elements and variations in shell growth. This review also highlights challenges involved with the interpretation of proxy data obtained from A. islandica and identifies future research needs. A. islandica does not easily reveal its secrets. It needs a holistic approach to unlock the multi-proxy records stored in their shells. The goal of this paper is to increase the recognition of this high-potential natural archive and encourage future interdisciplinary research. [Copyright &y& Elsevier]

Abstract: This paper presents alternating periods of geo-ecological fragility and stability in a highly sensitive environmental setting: the desert-margin area of southern Peru (14.5° S). There, we have to state that fragility was dominantly triggered by climatic changes, which induced several oscillations of the desert margin. During the mid-Holocene, the study area received the Holocene maximum of precipitation, soil formation occurred and the desert retreated, as loess–paleosoil formation documents. In contrast, the Titicaca region further south-east experienced extreme drought at that time. This regional antagonism between humid and dry conditions was a result of meridional shifts in moisture transport across the Andes and occurred also during pre-Columbian times. Considering a coincidence between environmental and cultural changes, we state that success and decline of civilizations were dominated by hydrological oscillations, triggering fertility as well as a critical loss of natural resources. Fragile periods, i.e. periods of geomorphological activity, occurred contemporaneous with cultural transitions. In response to spatial changing resources cultural foci were shifted. So, the success of pre-Columbian civilizations was closely coupled to areas of geo-ecological favorability, which were directly controlled by distinct regional impacts of large-scale circulation mechanisms, including El Niño–Southern Oscillation (ENSO). This spatial view on non-uniform environmental and cultural changes has not been thoroughly considered before. Therefore, for the first time this paper offers geomorphological evidence for diachronous Andean (agri-)cultural development, which was geographically determined. [Copyright &y& Elsevier]

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]

The sedimentary record in large marine embayments holds important information on Holocene environmental and sea-level changes. This paper investigates the evolution of a large subtropical marine embayment, Maputo Bay, in southern Mozambique. Using a combination of sediment cores, stable isotope data, seismic reflection profiling and 14 C dating, we show complex back-barrier changes during the Holocene and link these to stepped rises in sea level. Our data reveal a sea-level “slowstand” followed by an abrupt rise that we correlate with the 8.2 ka global rise in sea level. Sedimentological, isotope and seismic evidence point to a subsequent slowstand interspersed by two punctuated rises in sea level that formed clear tidal ravinement surfaces. Sedimentary changes in the embayment are primarily forced by sea-level change, whereby tidal ravinement surfaces sandwich normal regressive packages formed via marginal progradation and shallowing of the system during “slow-” or still-stands. Large marine embayment systems hold great potential in unravelling relative sea-level change. Axiomatically, this reduces their utility as archives of climate-change. [ABSTRACT FROM AUTHOR]

ABSTRACT This paper reports new radiocarbon determinations for late Holocene occupation in the Weipa region of Far North Queensland, Australia. Earth mounds along the margins of small wetlands and freshwater creeks developed mainly after 2200 years ago, but are concentrated within the past 500 years. Their establishment appears to be associated with changing environmental conditions and a regional increase in the availability of permanent water sources around 2200 and 500 years ago. These results have implications for earth mound chronology and possibly climate change understanding elsewhere in Northern Australia. [ABSTRACT FROM AUTHOR]

The source to sink process of terrigenous sediment from East Asia continent to the marginal seas is crucial for the understanding of land–ocean interaction and marine sedimentary process in the West Pacific continental margin. This paper presents element geochemical and Sr–Nd isotopic records of core CM97 in the Changjiang (Yangtze River) Estuary and core MD06–3040 on the inner shelf of East China Sea, aiming to reconstruct the Changjiang sediment source–to–sink transport process and its major controlling mechanism during the Holocene. Driven by the asynchronous evolution of the Indian and East Asian summer monsoon, the provenance of sediments accumulated in the Changjiang Estuary gradually changed from the upper catchment during the late glacial period to the mid–lower valley in the early–mid Holocene. With the intensive agricultural cultivation and urbanization development in the catchment during the late Holocene, the major source of Changjiang sediment into the sea shifted back to the upper catchment, again. The high–frequency ENSO activity may superimpose the effect of human disturbances on sediment source–to–sink process in the late Holocene. Therefore, the Holocene provenance evolution of Changjiang sediments in the East China Sea witnessed the changes of governing sediment erosion process within a large catchment from monsoon climate–dominated to anthropogenic driving. Our study also suggests the strong effect of hydrodynamics in coastal and shelf environments on sedimentary geochemical compositions, which deserves more attention in further sediment provenance study. [ABSTRACT FROM AUTHOR]

Holocene sequences of the Russian Arctic shelf seas are controlled by a combination of three main factors: deglaciation of the Late Pleistocene Barents-Kara ice sheet, global sea-level rise, and river runoff from Eurasia. Sedimentation in the Kara Sea is mainly defined by two latter factors. The lithological, grainsize, mineralogical, and micropaleontological compositions of the Holocene sequences of this basin have been widely studied, but only a few works report geochemical data. This paper considers comprehensive geochemical data on two cores from the Yenisei transect obtained during cruise of the R/V Akademik Petrov in 2000. Both the cores were dated by radiocarbon accelerator mass spectrometric method (AMS C) and analyzed using XRF and ICP MS methods. The study revealed and described differences in their chemical composition, which are caused by different facies settings of accumulation, their grain size composition, and influence of river run-off. [ABSTRACT FROM AUTHOR]

While mean grain size of sensitive component in muddy sediments from Chinese coastal seas was widely used as a proxy for reconstruction of the East Asian winter monsoon (EAWM) strength, many intractable problems still remain concerning the discrepancies in different studies. This paper provides a comprehensive overview of recent researches on the reconstruction of Holocene EAWM strength using sensitive grain size (SGS) in muddy sediments from the Chinese coastal seas. In the present study, 15 time-series of SGS in sediments from six mud areas are included. These records are summarized and compared during the last 8000 years, 3000 years and 150 years, respectively. The results show that trends of SGS time-series are inconsistent at millennial, multi-centennial and decadal time scales. The inconsistencies could be partly caused by age uncertainties and chosen SGSs. More important, grain size characteristics in sediments from some mud areas could be influenced by factors other than coastal currents driven by EAWM, such as sedimentary environments, riverine runoff and storms. Thus SGS of muddy sediments should be used with caution when reconstructing winter monsoon strength, especially those in the northern Yellow Sea and near the Yangtze River estuary. [ABSTRACT FROM AUTHOR]

The diverse lagoons and coastal lakes along the east coast of South Africa occupy incised valleys that were flooded during the rise and subsequent stabilisation of relative sea-level during the Holocene. Sedimentary deposits contained within these waterbodies provide an opportunity to investigate complex hydrological and sedimentological processes, and examine sea-level controls governing system geomorphic evolution. In this paper, we combine diatom and sulfur isotope analyses from two sediment cores extracted from the northern sub-basins of Lake St Lucia, a large shallow estuarine lake that is today largely isolated from direct ocean influence behind a Holocene-Pleistocene barrier complex. Analyses allow the reconstruction of hydrological changes associated with the geomorphic development of the system over the mid-to late Holocene. The sedimentary sequences indicate that St Lucia was a shallow, partially enclosed estuary/embayment dominated by strong tidal flows prior to ∼6200 cal. BP. Infilling was initiated when sea-level rise slowed and stabilised around present day levels, resulting in the accumulation of fine-grained sediment behind an emergent proto-barrier. Diatom assemblages, dominated by marine benthic and epiphytic species, reveal a system structured by marine water influx and characterised by marsh and tidal flat habitats until ∼4550 cal. BP. A shift in the biological community at ∼4550 cal. BP is linked to the development of a back-barrier water body that supported a brackish community. Marine planktonics and enrichments in δ 34 S suggest recurrent, large-scale barrier inundation events during this time, coincident with a mid-Holocene sea-level highstand. Periodic marine incursions associated with episodes of enhanced storminess and overwash remained prevalent until ∼1200 cal. BP, when further barrier construction ultimately isolated the northern basins from the ocean. This study provides the first reconstruction of the palaeohydrological environment at Lake St Lucia and highlights the long-term geomorphic controls that have shaped the recent evolution and natural dynamics of the system. Unlike most coastal lake systems, this system is particularly effective as an archive of geomorphological change. Systems driven by back-barrier modifications, such as Lake St Lucia, highlight how geomorphological changes driven by sediment-supply, climate and sea level can be distributed unevenly over several isolated back-barrier basins. [ABSTRACT FROM AUTHOR]

Beachrocks represent a significant paleo-environmental proxy because they can record both the vertical and the horizontal evolution of the shoreline. They have often been used to assess Holocene shoreline evolution and crustally induced Relative Sea-Level (RSL) changes in the Mediterranean Sea. In this paper, we used submerged beachrocks from Paros and Naxos Islands (Aegean Sea, Greece) to reconstruct the shoreline modification and provide new insights on the RSL evolution in central Cyclades. Paros and Naxos Islands are of great importance in terms of archaeological evidence of coastal occupation. However, the evolution of their coastlines was seldom explored. In this study, we coupled detailed underwater surveys, analysis of aerial photogrammetry, microstratigraphic analysis and luminescence dating to study beachrock outcrops found down to about 6 m below the present sea-level. We, then, spatially and chronologically constrained some major palaeogeographical changes of a number of coastal sectors of the two islands. Furthermore, the multiple analyses of beachrocks, sediment coring and archaeological data suggested that RSL rose by at least 3.8 m in the last 4.0 ka and that RSL variation in the last 2.0 ka did not exceed 2 m with respect to the present mean sea level. [ABSTRACT FROM AUTHOR]

Abandoned river channels may provide rich primary sources of palaeoenvironmental and cultural information elucidating landscape evolution, climate change, vegetation history and human impact, especially since the beginning of the Holocene epoch. However, although potentially an important resource, palaeochannels are not often recorded systematically and only rarely enjoy robust statutory protection (in the UK as Sites of Special Scientific Interest). In consequence, it is challenging to mitigate and manage this important geoarchaeological resource effectively within the UK planning framework. Whilst palaeochannels have long been recognised on aerial photographs and historic maps, the advent of airborne laser scanning (Lidar) and other remote-sensing technologies has provided a hitherto unforeseen opportunity to record such landforms and related features at a catchment scale. This paper provides a case study from the Nottinghamshire reach of the Trent Valley, where a desk-based methodology that is now being extended across the entire catchment has been developed for recording, geospatially locating and defining the attributes of observed palaeochannels. After outlining the methodology, we consider how this approach to resource management can aid archaeological research and future heritage management, especially in the light of predicted climate and environmental change. [ABSTRACT FROM AUTHOR]

Stratified rockshelter deposits form the most important source of information on the prehistoric hunter-gatherers of the Namibian Holocene Later Stone Age (LSA). This paper reports on two new test excavations conducted at rockshelters in the Sesfontein area in northwestern Namibia in 2005. Both archaeological sites are located between two archaeologically well researched regions, to the north Kunene and to the south the Brandberg and Erongo. Although the stratigraphies are rather problematic with regard to taphonomic integrity, their study identifies information that can be reliably used in order to contribute to our knowledge of prehistoric LSA hunter-gatherer societies in Namibia. The cultural material is examined in relation to available environmental, contextual and taphonomic data. [ABSTRACT FROM AUTHOR]

Deglacial sequences typically include backstepping grounding zone wedges and prevailing glaciomarine depositional facies. However, in coastal domains, deglacial sequences are dominated by depositional systems ranging from turbiditic to fluvial facies. Such deglacial sequences are strongly impacted by glacio-isostatic rebound, the rate and amplitude of which commonly outpaces those of post-glacial eustatic sea-level rise. This results in a sustained relative sea-level fall covering the entire depositional time interval. This paper examines a Late Quaternary, forced regressive, deglacial sequence located on the North Shore of the St. Lawrence Estuary (Portneuf Peninsula, Québec, Canada) and aims to decipher the main controls that governed its stratigraphic architecture. The forced regressive deglacial sequence forms a thick (>100 m) and extensive (>100 km2) multiphased deltaic complex emplaced after the retreat of the Laurentide Ice Sheet margin from the study area ca 12 500 years ago. The sedimentary succession is composed of ice-contact, glaciomarine, turbiditic, deltaic, fluvial and coastal depositional units. A four-stage development is recognized: (i) an early ice-contact stage (esker, glaciomarine mud and outwash fan); (ii) an in-valley progradational stage (fjord head or moraine-dammed lacustrine deltas) fed by glacigenics; (iii) an open-coast deltaic progradation, when proglacial depositional systems expanded beyond the valley outlets and merged together; and (iv) a final stage of river entrenchment and shallow marine reworking that affected the previously emplaced deltaic complex. Most of the sedimentary volume (10 to 15 km3) was emplaced during the three-first stages over a ca 2 kyr interval. In spite of sustained high rates of relative sea-level fall (50 to 30 mm·year−1), delta plain accretion occurred up to the end of the proglacial open-coast progradational stage. River entrenchment only occurred later, after a significant decrease in the relative sea-level fall rates (<30 mm·year−1), and was concurrent with the formation and preservation of extensive coastal deposits (raised beaches, spit platform and barrier sands). The turnaround from delta plain accretion to river entrenchment and coastal erosion is interpreted to be a consequence of the retreat of the ice margin from the river drainage basins that led to the drastic drop of sediment supply and the abrupt decrease in progradation rates. The main internal stratigraphic discontinuity within the forced regressive deglacial sequence does not reflect changes in relative sea-level variations. [ABSTRACT FROM AUTHOR]

In this paper, we discriminate the contribution of the different sediment sources into a river situated in the semiarid region of northern Chile, differentiating the ones driven by the paraglacial response from the ones yielded to the tributary-junction alluvial fans or the ones coming from the hillslopes. The sedimentary infilling is accurately described in the main landforms such as alluvial fans, alluvial terraces and landslides in the current valley floor where twenty-six 14 C AMS samples were picked up. The 14 C age data indicate that the aggradation in the uppermost part of the valley immediately postdates the glacial retreat at ∼15,000 14 C years cal. B.P. and spans the whole Holocene starting at 11 ka. B.P. and finishing about 2 ka B.P. The main sources for lateral inputs are debris flows from tributary catchments in the portion where the river is embedded in between 1000 and 2000 m a.s.l as well as catastrophic landslides. Additionally, an extensive detailed geomorphological mapping is provided to discuss the meaning of the ages together with an assessment of where the samples came from. Finally, the dataset and field criteria provided in this work contribute to better perform paleoclimatological interpretations for the semiarid fluvial systems of northern Chile. These interpretations usually consider the increased influence of the westerlies during the Holocene and the span of time that the paraglacial response delivers glacigenic sediments into the system. [ABSTRACT FROM AUTHOR]

This paper presents the first attempt at qualitatively and quantitatively evaluating the sedimentary contribution of the Puna plateau to the loess and soils of the Argentinean Pampas. The origin of the Pampean sediment has been traditionally ascribed to northern Patagonia, but new evidence supports a dual supply: western Central Andes/North Patagonia and Puna/Altiplano Plateau. Three different lines of evidence show here that Puna dust supply is active and produces significant sedimentary deposition up to places like Buenos Aires city. The first evidence is meteorological and we show here one event related to an abnormal rainfall that deposited large quantities of a reddish-brownish silt eroded out from the Puna, calling the attention of the environmental agency of Buenos Aires city. The second evidence is the sampling of active wind transport collecting extremely coarse material carried out in the saltation layer, suggesting the fine grained material escapes the area as fugitive dust. This also demonstrates that observed gravel-bearing bedforms of the Puna are active, and that the transport system seems to be activated by polar fronts only. Results show that the saltation curtain is abnormally thick and coarse, suggesting that the kinetic energy peaks ca. 7–10 times higher than for normal saltation, while the transported grain size coincides with the lagged sediment in this basin composing different bedforms, varying between sandy gravel and gravelly sand. The third evidence is the quantification of the exported material by defining a reference surface as the initial time of evolution, and the present day surface. The initial surface is an alluvial surface of an estimated age of 11–12 ka. BP. Volume balance was achieved by a detailed topographic, stratigraphic and geophysical survey, reconstructing old alluvial and present surfaces. Two gridding methods were used, and more conservative results of the volume balance, indicate a total erosion of ca. 3.386 hm 3 of sediment in 72 Ha, spliced in 0.963 hm 3 of sediment that was left within the place forming gravel dunes, while the remaining volume of ca. 2.423 hm 3 is sediment truly exported from the surveyed area. Results imply a continuous blanket of ca. 4 m thick of sediment exported out of this basin in the Holocene. These findings prove that the Puna contribution to the Chaco-Pampean plain is significant, although not unique. Thus, true proportions of sediment contribution to soils and loess from these multiple sources should be better evaluated in future studies. [ABSTRACT FROM AUTHOR]

In recent decades, the area around Sierra de Atapuerca has been the focus of many archaeological excavations and surveys under research projects and also management or rescue archaeology. From 1999 to 2007, one such project analysed the evolution of prehistoric settlement around Sierra de Atapuerca during the Holocene. The fieldwork was based on ten archaeological surveys, eight of them using a full-coverage intensive systematic method in a 314 km 2 area (10 km radius around Mayor Cave, Sierra de Atapuerca), and two intensive systematic surveys of the sites. This paper presents a thorough, up-to-date cartography of every Holocene archaeological site in this area as at 2014: surveyed sites, excavated sites, caves and megalithic structures. We also discuss GIS mapping techniques and geoespatial databases applied to archaeological surveys, we evaluate the megalithic structures and the settlements excavated at other digs, and we assess the relevance and contributions of each archaeological operation. The results of our research project have proven highly successful, with an overall Holocene spatial distribution of more than 200 archaeological sites from the Neolithic to the Bronze Age: caves, open air sites and megalithic structures. These findings, combined with the GIS results, show that the area around Sierra de Atapuerca may be one of the best potential sources for deeper knowledge of Late Prehistory on the Northern Iberian Plateau. [ABSTRACT FROM AUTHOR]

Planktonic foraminiferal assemblages are used as proxies of surface ocean variations, as documented in five marine sediment cores from the Bay of Campeche (BoC), Gulf of Mexico (GoM), spanning the last 34,000 cal yrs BP. This paper seeks to better understand the regional history by studying cores taken in the poorly studied Southern GoM. Multivariate factor analyses calculated five assemblages at millennial to glacial–interglacial scales. During the last glacial period, including the Last Glacial Maximum (LGM), the assemblage contained G. inflata , and T. sacculifer which suggests the presence of colder and less saline waters than younger times; although during the LGM, saltier waters and weaker ocean circulation may have occurred. During the deglaciation, the deep-dweller G. crassaformis suggest a reorganization of deep-thermocline waters and the establishment of transitional conditions, where mild to warm waters entered the Gulf. During the early to mid-Holocene, the tolerant tropical species G. ruber pink suggests salinity variations and warmer conditions than the previous interval. During the late-Holocene, only warm species comprise the assemblage, where the group G. menardii and G. truncatulinoindes suggest warm and stratified conditions, with an oxygen decrease in the thermocline, and rather high salinity levels linked to reduced moisture exported from the Pacific due to the progressively more influential ENSO-like conditions. Prominently, all the assemblages include the species G. ruber white chromotype, suggesting that the environmental conditions are continuously favorable to this abundant species. These scenarios show agreement to previous reconstructions in northern and western GoM, the Caribbean, as well as paleoclimate on land, which are mostly regulated by the position of the ITCZ, changes in the expansion of the Atlantic Warm Pool, the tropical circulation, and teleconnections with nearby regions. [ABSTRACT FROM AUTHOR]

This paper considers regularities governing the formation of automorphic tundra soils on glacial loamy deposits containing relict organic matter mainly represented by very fine plant detritus. Drainage, microtopography, and cryoturbation activity are the major controls of the development of these soils. With an increase in drainage, the following pedogenetic trend is observed on the surface of yedoma (Ice Сomplex) areas: gleyzem-cryozem-cryometamorphic soil. The climate change in the Holocene induced quick transformation of topography and general landscape situation and promoted formation and development of cryogenic soil complexes in the considered territory. Upon the low intensity of pedogenesis, the features and properties of previous soil formation stages are often preserved in the soil profiles; these are: gleyzation, peat accumulation, and cryoturbation. [ABSTRACT FROM AUTHOR]

In this paper, we reconstruct the Holocene paleoenvironmental evolution of the Guadiana Estuary, southwestern Iberian Peninsula. Two previously studied boreholes (CM3 and CM5) were revisited and analyzed in the light of a foraminifera modern analog approach. Cluster analyses define four assemblages with different biocenotic, taphonomic, elevation and distance-to-sea settings, which serve as a baseline for paleoassemblages interpretation. Faunal changes along the sedimentary sequences, together with previous sedimentological and chronological data, redefine the different phases of environmental evolution in the Guadiana Estuary since ca. 13 kyr cal. BP, with special emphasis on the Holocene marine highstand. Estuarine flooding began synchronously in both locations (ca. 9 kyr cal. BP) but manifested differently in each sedimentary sequence. The most seaward borehole records a more evident and longer highstand (ca. 8.8-3.8 kyr cal. BP), characterized by the occurrence of subtidal environments and by the presence of open marine species (Pararotalia cf. spinigera, planktic forms and a significant number of exotic/allochthonous tests), indicating warmer and more marine conditions than today. In the most landward borehole, the highstand is shorter (ca. 8-7.6 kyr cal. BP) and less intense, characterized by the presence of a diverse, mainly autochthonous, open estuary assemblage, dominated by Ammonia aberdoveyensis and Haynesina germanica. At 4.4 kyr cal. BP, during a long deceleration phase of regional sea-level rise, a short but well-defined pulse of marine influence is recorded in CM5, when open estuarine assemblages reappear and replace marsh agglutinated assemblages, suggesting a new submergence phase. This short event is not identified in the previous works carried out in the same area, thus further data are needed to understand whether it is consequent from a global, warming period or whether it resulted only from local and ephemeral forcing effects. [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]

Food security intertwined with the need to maintain biological survival of a demographically viable population is the basic long-term policy for all societies. This paper compares selected cases of successful and failed Paleolithic groups of hunter-gatherers, as recorded archaeologically across Eurasia and Africa, in responding to the impacts of abrupt climatic changes. The complex prehistory of Pleistocene foragers is briefly compared to strategies adopted by Neolithic farmers. The major difference between forager and farmer economies is not their social organization as much as the access options to alternative territories and food resources. Open Pleistocene landscapes across Eurasia and Africa allowed for movements of Paleolithic groups over large distances with or without adopting new exploitation techniques. Successes and failures that we measure in a chronological macro-scale left archaeological evidence (lithic assemblages, faunal remains, occasional flimsy dwellings, etc.) in various regions, recorded by systematic and comprehensive surveys and excavations. However, we miss the chronological micro-scale of most of the Paleolithic period that could inform us about extinctions. We can identify only survival stories explained as successful adaptations. When farming communities were established during the course of the Holocene, variable modes of social and economic interactions and group resilience evolved in order to secure survival in years of bad harvests. Interactions with foragers and herders, competition, raids, village abandonment, migration into others' territories, were among the optional strategies. Due to the difference in chronological scales between 2.6 Ma of the Paleolithic period and the 12 Ka of the Holocene (or Anthropocene), we can more easily recognize the role of abrupt climatic changes among prehistoric societies during the Terminal Pleistocene and the Holocene and evaluate the success and failure of both, hunter-gatherers and farmers. [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]

Abstract: Despite the present hyper-aridity, archaeological investigations in South-east Arabia have demonstrated that the region supported extensive human communities throughout the Neolithic and Bronze Age. These early populations utilised the region’s natural environment in a variety of ways, ranging from the exploitation of coastal resources to practicing pastoral and agrarian lifestyles in the interior. Palaeoclimate data suggests the corresponding period was characterised by considerable climatic variability yet, to date, few studies have attempted to investigate the relationship between climate, the environment and early human populations in the region. This paper combines new high-resolution palaeoclimate data from Awafi palaeolake, United Arab Emirates (UAE), with the region’s archaeological record from the Neolithic through to the onset of the Bronze Age. The evidence presented in this paper suggests that the environment of South-east Arabia offered different constraints and opportunities for early human occupation and subsistence. In particular, abrupt phases of aridity are demonstrated to have had a profound impact. Most notable is the change which occurred following the onset of climatic aridity at 5900 cal yr BP, when the region’s semi-nomadic, herder-gatherer populations abandoned much of the landscape and concentrated in selected environmental refugia, such as along the northern Omani coast. Human repopulation during the Bronze Age coincided with a return to more pluvial conditions under which a network of oasis agricultural settlements appeared along the piedmont zone of the northern Hajar Mountains. [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]

The evolution of the East Asian summer monsoon (EASM) during the Holocene has long been of significant interest. Knowledge of past EASM variability not only increases our understanding of monsoon dynamics on a long timescale, but it also provides an environmental and climatic background for research into Chinese cultural development. However, the timing of the EASM maximum remains controversial. The popular concept of an 'early Holocene maximum' is mainly based on speleothem δO ( δ O) records from caves in southern China; however, the interpretation of δ O as a reliable proxy for EASM intensity is being increasingly challenged. The present paper is a critical review of the climatic significance of the δ O record from China. Firstly, we suggest that precipitation in northern China is an appropriate index of EASM intensity, the variation of which clearly indicates a mid-Holocene monsoon maximum. Secondly, an interregional comparison demonstrates that the precipitation record in northern China is quite different from that in southern China on a range of timescales, and is inconsistent with the spatial similarity exhibited by speleothem oxygen isotope records. Furthermore, both modeling and observational data show that the δ Oc records from southern China indeed reflect changes in precipitation δ O ( δ O) rather than precipitation amount, and therefore that their use as an EASM proxy is inappropriate. Finally, we address several significant monsoon-related issues-including the driving mechanism of the EASM on an orbital timescale, the climatic significance of speleothem oxygen isotopes, and the relationship between atmospheric circulation and precipitation in monsoonal regions. [ABSTRACT FROM AUTHOR]

This paper studies the changes in the geomorphological dynamics recorded in 18 ephemeral streams located on the east side of Loma Pelada (Tafi Valley), a part of the Sierras Subandinas (Northwest Argentina). The applied methodology is based on photointerpretation, field survey, and descriptions of the Holocene alluvial fillings dated by tephras, archaeological artefacts, and absolute datings. The records show a coupled system of slope-terrace-alluvial fans resulting from the environmental changes of four alternating aggradation/degradation stages. The oldest stage (1) was generated by climatic causes and covers Early to Mid-Holocene ( ca. 13,000–10,000 BP to ca. 4200 BP). After the incision of these accumulations, a new aggradation stage (2) was triggered by anthropogenic activity occurring from right before 2500 BP to the 15th century. During that time human occupations of the Tafí Valley were intense. Two wetter events occurred around 4200 and 2800 BP in the area, related to global cooling phases. Lastly, two more recent phases (3 and 4) are associated with the climatic variability of the LIA and the Present Warm Period. The results highlight the sensitivity of headwater catchments of dry subtropical mountainous areas to climate changes, anthropogenic impact, and their relationship with global climatic data. [ABSTRACT FROM AUTHOR]

In this paper we report new data on peat carbon (C), nitrogen (N) and phosphorus (P) concentrations and accumulation rates for 15 sites in the UK. Concentrations of C, N and P measured in peat from five ombrotrophic blanket mires, spanning 4000–10,000 years to present were combined with existing nutrient data from ten Scottish ombrotrophic peat bogs to provide the first UK perspective on millennial scale macronutrient concentrations in ombrotrophic peats. Long-term average C, N and P concentrations (0–1.25 m) for the UK are 54.8, 1.56 and 0.039 wt%, of similar magnitude to the few published comparable sites worldwide. The uppermost peat (0–0.2 m) is enriched in P and N (51.0, 1.86, and 0.070 wt%) relative to the deeper peat (0.5–1.25 m, 56.3, 1.39, and 0.027 wt%). Long-term average (whole core) accumulation rates of C, N and P are 25.3 ± 2.2 gC m − 2 year − 1 (mean ± SE), 0.70 ± 0.09 gN m − 2 year − 1 and 0.018 ± 0.004 gP m − 2 year − 1 , again similar to values reported elsewhere in the world. The two most significant findings are: 1) that a regression model of N concentration on P concentration and mean annual precipitation, based on global meta data for surface peat samples, can explain 54% of variance in N concentration in these UK peat profiles; and 2) budget calculations for the UK peat cores yield an estimate for long-term average N-fixation of 0.8 g m − 2 year − 1 . Our UK results, and comparison with others sites, corroborate published estimates of N storage in northern boreal peatlands through the Holocene as ranging between 8 and 15 Pg N. However, the observed correlation of N% with both mean annual precipitation and P concentration allows a potential bias in global estimates that do not take this into account. The peat sampling data set has been deposited at the NERC Data Centre ( Toberman et al., 2016 ). [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 paper documents the history of vegetation assemblage in Honghe Wetland (NE China) during the last 6200 years. Vegetation changes were reconstructed based on high-resolution plant macrofossil analysis of sedimentary sequence obtained from Honghe National Nature Reserve located in Sanjiang Plain, in conjunction with Accelerator Mass Spectrometry (AMS) 14 C radiocarbon data. Results indicate that plant macrofossil composition of Honghe wetland ecosystem are dynamic and have undergone several significant changes. Around 2500 cal yr BP, plant composition transited from Equisetum fluviatile community to Carex lasiocarpa - Drepanocladus aduncus community, and then following by Drepanocladus aduncus community at 460 cal yr BP. Another major vegetation changes occurred at 220 cal yr BP, transitioning to Carex sp. community. By comparison between the plant macrofossil assemblages and the climate changes during the last 6200 cal yr BP, we suggest that ASM (Asian summer monsoon) is the main driving force for the vegetation succession before the impacts of human activities. Since some restoration programs have been undertaken at Honghe wetland, thus our results can provide valuable baseline data for assessment of the practicability and suitability of the former restoration plan and the further designing of conservation management and restoration targets. Since the vegetation composition of Honghe wetland is pronouncedly sensitive to water level, it can be inferred that wetland ecosystem can be restored to near-natural condition through the effective management and restoration by controlling the water source of the wetland. [ABSTRACT FROM AUTHOR]

Millennial-scale variations in the Asian monsoon vapor transport are always associated with long-term changes in monsoon rainfall according to the conventional understanding. However, recent advances in monsoon studies suggested that regional monsoon rainfall has different responses to monsoon vapor transport. This paper presents a comparison between monsoonal vapor and precipitation records along the path of the Asian summer monsoon vapor transport. Pedogenic carbonate δ 18 O values in both surface sediment and Holocene eolian and lacustrine sediments from the Shiyang River drainage basin were used to investigate the variations of the Asian monsoon vapor transport. Meanwhile, Holocene lake-level changes of the terminal lake were reconstructed to reflect the monsoon precipitation variability. The results show that millennial-scale monsoon vapor transport is in accordance with low-latitude summer insolation, while the increasing summer monsoon rainfall during the early Holocene lags the monsoon water vapor transport. In addition, the relatively cold oceans left over from glacial periods and slow melting of ice sheets may temper the onset of the rainfall. These findings can provide insights into the interpretation of the asynchronous Holocene records from lakes and caves in East Asia. [ABSTRACT FROM AUTHOR]

The paper deals with new fossil material, about 9400 cheek teeth, from 24 elementary samples received from loose deposits of 2 karst cavities – Chernorechka and Chernorechka-2, and 2 rock shelters – Verbluzhka-1 and Verbluzhka-2 located in the Ural–Sakmara interfluve (at about 51°N). One small lagomorph taxon (Lagomorpha) and 30 rodent taxons (Rodentia) were determined from which 4 taxon doesn't inhabit investigated territory nowadays: Eolagurus luteus , Pygeretmus pumilio and Pygeretmus sp., for Eliomys quercinus marked the most southern-east point in the area history. Nine stages of the community's development were marked out. The domination of Lagurus lagurus , Eolagurus luteus and Microtus gregalis from the most ancient community concerned it to typical Late Pleistocene steppe type of communities described from the adjacent South Trans-Urals territories. The Holocene time interval is marked by the domination of Ellobius talpinus and Microtus ex gr. arvalis as well as yellow steppe lemming in the community core (four stages). Then in the core composition appeared Sicista sp. and Cricetus cricetus (four stages) and small mammal communities obtained the mesophilous look. The increasing of xerophilous elements in the last centuries and dozen years reflected regional peculiarities of modern steppe conditions in the south extremity of the Ural mountains. [ABSTRACT FROM AUTHOR]

This paper examines Holocene tends in subsistence practices through the examination of archaeological faunal remains from the Bugul'deika II habitation site on the west shore of Lake Baikal, Russian Federation. This data indicates that the primary focus of subsistence activities at the site in almost all periods was the hunting of Baikal seals ( Phoca sibirica ). While some deer and other fauna are represented in most cultural layers, they appear to be supplementary resources throughout the Early and Middle Holocene period of site use. By ∼2900 cal. BP, domesticated ungulates appear at the site, and become increasingly more relatively abundant through time. Humans using the site during these periods also continued to use wild fauna, particularly Baikal seals. Yearlings and other juveniles were the most commonly taken seals at the site, and most were killed in the late winter or early spring when the lake was ice covered. The overall pattern of fauna use at the site is very similar to that at other sites located on the open shoreline of Lake Baikal, but contrasts sharply with fauna use at sites located along the Little Sea shoreline of the lake, which focuses of littoral fish. Finally, while Middle Holocene human cemeteries in the study area have abundant remains of deer, and stable isotope data on human remains from them indicate some dietary reliance on such herbivores, remains of deer are not found in abundance in any local habitation site. [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]

We present and appraise a large compilation of peatland palaeoecological research in Great Britain, and discuss the value of these data for secondary analysis. We identify 475 radiocarbon-dated palaeoecological records from British peatlands published since 1970. Peatland palaeoecological research has been widespread but with some clear spatial biases reflecting factors such as accessibility and the location and interests of active researchers. We show that basic details such as stratigraphic descriptions, site coordinates and full details of radiocarbon dates are omitted from publications with surprising frequency and note the large quantity of data that only ever appears in PhD theses. To allow papers to remain concise while presenting essential background information we propose a system of standardised meta-data in online supplementary material. The extensive body of palaeoecological data for British peatlands has been relatively unexploited. The compilation we present will be a valuable aid in making better use of this data resource. [ABSTRACT FROM AUTHOR]

Aim Projections of human impact on the environment and biodiversity patterns are crucial if we are to prevent their destruction. Such projections usually involve the assumption that the same human activities always affect biodiversity in the same way, either in geographically distant areas within the same time-scale or in the same areas in different periods. In this paper, plant and snail fossils from central Europe that cover the last 12,000 years provide evidence against this assumption. Location Central Europe. Methods We examined fossil data on central European plants and snails and extracted time-series of (1) local species richness (alpha diversity) at a scale of approximately 300 m × 300 m and decays of (2) the Jaccard index and (3) Simpson's beta with increasing distance (up to approximately 400 km) through time. Results We show that two vital biodiversity patterns follow neither oxygen-isotope nor borehole temperature proxies, but instead vary between archaeologically known periods, with the most noticeable and irreversible breaks (1) when arable agriculture was introduced into central Europe, (2) when the Roman Empire collapsed, and (3) during the event known as the 12th-century colonization in central Europe. The patterns computed from data across time sometimes contradicted the patterns computed across space. Main conclusions We therefore infer that people can, and sometimes have, contributed to temporal changes in ecological rules that are seemingly general across space. Our findings indicate that the changes in ecological rules are so substantial that efforts to project future biodiversity based on space-for-time substitution might fail, unless we gain knowledge about how these general rules are altered. [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]

Recent research in northern Iceland has highlighted a significant period of rock slope instability during the early Holocene due to the combined effects of postglacial rebound, relative sea-level fall, and glacially oversteepened mountain slopes. Using the Vatn landslide (Skagafjörður, central northern Iceland) as an example, this paper focuses on this period and describes the sequence of events that led to landsliding. Geomorphic mapping, stratigraphical evidence, and both radiocarbon and tephra dating were applied. Collectively, the data acquired indicate that the landslide occurred between 11,400 and 10,790 cal. yr BP. However, while rock slope failure represents a significant disintegration of mountain slopes, this study suggests that large postglacial landslides might also play a role in arresting sediment transport from other hillslope processes rather than contributing large volumes of sediment. [ABSTRACT FROM AUTHOR]

Understanding parasite history and the evolution of host/parasite relationships is one of the most important aspects of paleoparasitology. Within the framework of this research topic, this paper focuses on the human pathogenic amoeba, Entamoeba histolytica . The compilation of all the available archaeological data concerning this parasite leads to a first glimpse of the history of this parasite of current medical importance. Paleoparasitological investigation into this parasite uses immunological techniques and shows that the modern strain of E. histolytica has been present in Western Europe since at least the Neolithic period (3700 years BCE), and could have originated in the Old World. The appearance of the modern amoeba strain in the pre-Columbian Americas and the Middle East around the 12th century CE gives rise to hypotheses as to how human migrations (Atlantic or Pacific routes) contributed to the diffusion of this pathogen, resulting in its current distribution. This compilation proves that parasites are valuable proxies for studying past human and animal migrations, and should be given more consideration in the future. [ABSTRACT FROM AUTHOR]

This paper aims to achieve an improved understanding of the long-term change trends of precipitation δD and δ 18 O values (δD p and δ 18 O p ) in the Asian monsoonal region and their relationship with the corresponding humidity trends during the Holocene. To do this we first review the observed modern spatial pattern of summer precipitation distribution in the East Asian summer monsoon (EASM) region under different EASM intensities, and the relationship between modern observed δ 18 O p values and corresponding precipitation amounts on monthly and inter-annual timescales in the EASM and Indian summer monsoon (ISM) regions. Second, we compare Holocene lacustrine and marine compound-specific hydrogen isotopic records of n -alkanes/ n -alkanoic acid (δD n ), lacustrine authigenic carbonate and cave stalagmite oxygen isotopic records (δ 18 O c and δ 18 O s ) from the Asian monsoonal region, all of which are closely related to δD p and δ 18 O p variations. The results demonstrate that in both the ISM and EASM regions, all of these isotopic records exhibit roughly similar long-term characteristics, i.e. they were all more negative during the early-Holocene and early mid-Holocene (ca. 11–6 ka B.P.; B.P. means before present, present = 1950 AD), and then became more positive towards the late-Holocene. Third, we compare representative paleo-humidity records from the Asian monsoonal region; the results confirm that, in the ISM region, a humid interval occurred in the early-Holocene and early mid-Holocene (ca. 11–6 ka B.P.) and subsequently the climate became more arid towards the late-Holocene. This indicates an enhanced ISM during the early-Holocene and early mid-Holocene (ca. 11–6 ka B.P.), and an ISM of decreasing intensity towards the late-Holocene. On a Holocene orbital scale, both δ 18 O p and δD p appear to be controlled by an “amount effect” in the ISM region, consistent with the region's inter-annual modern δ 18 O p data. This evidence indicates that both δ 18 O p and δD p paleo-records are significantly related to paleo-humidity in the ISM region. In contrast, Holocene humidity variations in the EASM region exhibit clear spatial differences: a humid mid-Holocene interval (ca. 8–3 ka B.P.) occurred in southern and northern China, but an arid interval from ca. 7–3 ka B.P. occurred in central China, in the middle reaches of the Yangtze River. Based on precipitation distribution patterns under different EASM intensities in the EASM region over the past few decades, we conclude that EASM intensity was enhanced during the mid-Holocene (ca. 8–3 ka B.P.). Relative to the ISM intensity, the response of EASM intensity to summer insolation was relatively slow. In the EASM region the relationship between climate and δ 18 O p and δD p is more complex, consistent with analyses of regional inter-annual modern δ 18 O p data. This evidence demonstrates that both δ 18 O p and δD p paleo-records cannot be used directly as paleo-humidity (i.e. precipitation amount or EASM intensity) indicators in the EASM region. Further comparison and analyses demonstrate that the coupled variations in west–east Equatorial Pacific temperature gradients and the West Pacific subtropical high (WPSH) played an important role in determining EASM intensity during the Holocene. [ABSTRACT FROM AUTHOR]

Shell mounds, or middens, are artificial accumulations of food remains such as shells, sediments, artefacts and remains from daily life and funerary rituals, which were deposited in our study area by groups of Sambaquian fisher-hunter-gatherers. These mounds contain remains, which are representative of the fauna and flora at the time they were formed, enabling the recovery of palaeoenvironmental data related to biodiversity of taxa and biogeography, 14C dating and analysis of changes in the patterns of marine biodiversity and ocean circulation. This paper uses the Casa de Pedra shell mound rock shelter, located in São Francisco do Sul, state of Santa Catarina, southeastern Brazil, to study aspects of the palaeoenvironment through analyses of the archaeological material of the site, which contains well-preserved phytoliths and sponge spicules. Among the phytoliths, those from grasses predominate and some trees and palms were present, with no variation in vegetation type during the period of site occupation, between 5,470 and 4,460 years bp. Despite the general stability of the vegetation, a small increase in the density of the tree cover was identified from the base to the top, which may be related to an increase in precipitation, and is in agreement with other palaeoenvironmental studies carried out in southern Brazil. [ABSTRACT FROM AUTHOR]

Abstract: The speculative method and data suggested by Lario et al. [J. Lario, C.J. Dabrio, C. Zazo, J.L. Goy, F. Borja, A. Cabero, T. Bardají, P.G. Silva, 2010, Comment on “Formation of chenier plain of the Doñana marshland (SW Spain): Observations and geomorphic model” by A. Rodríguez-Ramírez and C.M. Yáñez-Camacho [Marine Geology 254 (2008) 187–196], Marine Geology, this Issue] and other researchers in their papers and comments about the marine radiocarbon reservoir effect in the Gulf of Cádiz are unreliable. The previous regional investigations (Soares''s comment [A.M.M. Soares, 2010, Comment on “Formation of chenier plain of the Doñana marshland (SW Spain): Observations and geomorphic model” by A. Rodríguez-Ramírez and C.M. Yáñez-Camacho [Marine Geology 254 (2008) 187–196], Marine Geology, this Issue] and others papers) about the calibration of radiocarbon marine samples cannot be ignored or undervalued. At present, accurate and reliable ΔR values exist and must be used when building up chronological frameworks for the interpretation of Holocene marine environments. During the interval 2000–200 BP or circa 4500BP ΔR values from the Andalusian coast of the Gulf of Cádiz are invariably lower than those from the Algarvian coast. Its calculated weighted mean is −135±20 14Cyr. Between 4000BP and 2000BP ΔR data are still lacking but a conservative ΔR value of 100±100 14Cyr can be adopted. [Copyright &y& Elsevier]

Abstract: Rodríguez-Ramírez and Yáñez-Camacho (2008), Rodríguez-Vidal et al. (2009) and Rodríguez-Ramírez et al. (2009) have kept an ongoing discussion about the validity of radiocarbon ages in reconstructing Holocene palaeogeographical models in the Gulf of Cadiz. The discussion considered the validity and correctness of the ΔR value to be used in the area to calibrate radiocarbon ages of marine samples. These papers suggest that the ΔR value proposed by Lario (1996) and Dabrio et al. (1999, 2000) is erroneous, and consequently, that all the evolutionary models based on radiocarbon ages from marine samples that have been proposed in this area since 1996 must be revised. However, the papers commented here use erroneously the R, regional R and ΔR values. After reviewing the published data, it is apparent that the most reliable values of ΔR in the Gulf of Cadiz for middle-late Holocene samples range between ΔR =35±85yr and ΔR =95±15yr. This means that the values used in Lario (1996) and Dabrio et al. (1999, 2000) fall in this range, and also that the calibrated ages used by several authors adopting these values are fully reliable. Calibrations using ΔR values inside this range do not yield significant differences in terms of geological age owing to the magnitude of errors resulting from the methods employed. [ABSTRACT FROM AUTHOR]

Tracksites representing early human occupation are rare in South America. However, they have been reported in association with mammal and bird tracks from two coastal sites in Buenos Aires Province, Argentina. Both sites are reported in separate papers in this volume. In this paper a brief summary of the better known site is given on the basis of published information and the author's observations. [ABSTRACT FROM AUTHOR]

Abstract: A paleolimnological study can be particularly accurate in situations where the species found in the sediments have persisted in the same lake and can provide a direct modern analogue for interpretation. Lake Tigalmamine, thus, represents an exceptionally favourable context, compared to most paleolakes in North Africa, as this site allows comparing the fossil remains of the Characeae to those produced by the living plants. Tigalmamine is a hydrosystem composed of three karstic lakes located at 1626m above sea level in the Middle Atlas of Morocco. The site had been the subject of a 16m long core taken in the center of the central lake under 16m of water (core C 86 in Lamb and Kaars, 1995 [The Holocene 5 (1995) 400–408]). The section represents the total of the Holocene from 10,200 BP to Present (El Hamouti et al., 1991 [Comptes Rendus de l’Académie des Sciences de Paris 2 (1991) 259–265]; Lamb et al., 1995 [Nature 373 (1995) 134–137]). The latter published a synthesis of the pluridisciplinary studies conducted on this core. Also, the numerous gyrogonites isolated from that core had been determined as Chara hispida (Soulié-Märsche in Benkaddour, 1993 [Changements hydrologiques et climatiques dans le Moyen-Atlas marocain : chronologie, minéralogie, géochimie isotopique et élémentaire des sédiments lacustres de Tigalmamine. PhD thesis, Université Paris-Sud, Orsay (inédit)]). Further fieldwork at Tigalmamine by the authors of the present paper in year 2000 showed that Chara hispida is still present in the lake where it forms a belt of submerged vegetation restricted to the range of 2 to 9m water depth. This paper describes the morphological and ecological characteristics of the extant Chara hispida as a reference for the interpretation of the fossil remains. Based on these data, the frequency changes of the gyrogonites in the core sediments become significant in terms of bathymetry. The detailed analysis of the charophytes from the core, as a complement to the previous studies, confirms the existence of four Holocene phases with lake level low stand at Tigalmamine. The aim of the present study is to enhance the value of the charophytes as a useful complementary tool for paleolimnological reconstruction. [Copyright &y& Elsevier]

In this paper, a lithological study taking into account trace metals of the profundal sediments from Slupiañska Bay in Wigry Lake is presented. A profile 5.26 m long has sandy muds at the bottom and moving upwards layers of calcareous gyttja, lacustrine chalk, and again calcareous gyttja are present. The profile is continuous, typical for the sediments of NE Poland formed from Aller&3x00F8;de to recent time. The results of the lithological analysis were correlated with results of high-resolution seismic survey. The results together with radiocarbon dating are part of interdisciplinary complex re- search comprising paleobiological study of pollen, Cladocera, diatom successions and human activity, which will be published in successive papers. [ABSTRACT FROM AUTHOR]

Abstract: This paper establishes an eight thousand year history of anthropogenic metal pollution at one of the oldest, most important and longest sustained sites of the extraction and smelting of copper ores in the Old World: the Faynan Orefield in Jordan, which is located between the hyper-arid southern desert and the front of the wetter Mountains of Edom. The modern land surface is shown, in significant part, to be a complex palimpsest of archaeological sites, metal pollution of various ages and ore processing deposits. Quantitative and qualitative observations of the storage and cycling of heavy metals through the local natural and domestic systems have produced a body of information on processes with which the past has been interpreted. Heavy metal concentrations in semi-continuous sedimentary bodies indicate that over the last 1500years, metals were removed by natural processes at a comparatively slow rate given the scale of the original anthropogenic metal burden: the proportions of lead with respect to copper have increased as the overall metal burden has been lowered. Distinctive anthropogenic metal-pollution signatures have been detected in ash- and charcoal-rich deposits that were discarded onto the banks of a perennial stream in the late Neolithic. At present, the nature of the human activities that might have produced these pollution signatures is unknown. Substantial metal pollution from industrial-scale smelting activity was present from the Early Bronze Age. The intensity of heavy metal pollution produced in Classical Times locally exceeded that recorded at major European copper smelting centres in the nineteenth century A.D. The pollution evidence indicates that intensive copper smelting at the immediate area took place until approximately the end of the Byzantine period; with the exception of one further minor episode of smelting radiocarbon dated to cal. BP 530–330. An observed partial, but perhaps significant, parallelism is also noted between this local record and the records of the metal burdens of the northern hemisphere determined at mire or ice-sheet sites at high-altitudes or high-latitudes. The paper discusses the extent to which this parallelism might be a geochemical indicator of the actual existence of “economic systems” of a geographical scope and scale to have both exercised substantial “pull” upon the resources of such isolated and difficult locations at the Wadi Faynan, and to have generated sufficient overall metal pollution to have materially altered the chemistry of the global atmosphere. The comparative absence of quantitative information upon the nature, spatial scale and impacts of human, industrial and natural processes affecting metal-pollution in other metal-rich arid lands provides a significant impediment to such approaches that seek to research “locally and think globally”. [Copyright &y& Elsevier]

Dallund Sø, a lake on the island of Funen, Denmark, is positioned in a landscape that has been heavily impacted by human activities and land-use change over thousands of years. In 1998 a project was initiated to utilize a variety of palaeoecological analyses to investigate lake response to changing land use through the period of agricultural impact on the Danish landscape, i.e., the last 6000 years. This paper describes the overall aims of the study, the natural and cultural setting, sediment core collection, sampling and physical properties, the chronology and erosion history. The long-term changes in the terrestrial and aquatic ecosystem are assessed in the following papers in this Research set using (i) pollen, (ii) diatoms, macrofossils and Pediastrum and (iii) zooplankton. These papers are followed by a synthesis paper focusing on the linkage between land-use change and lake development. [ABSTRACT FROM AUTHOR]