Palaeoenvironmental Research Research Articles

Holocene landscape evolution, palaeoclimate and human impact in the Fotsch Valley, Stubai Alps, Austria: Interrogating biomarkers, stable isotopes, macrofossils and palynological indicators from a subalpine mire archive

Peatlands are receiving increasing attention in palaeoenvironmental research and represent very useful terrestrial archives for reconstructing vegetation, climate and human history. Previous palaeoenvironmental studies in the Fotsch Valley, Stubai Alps, Austria, focused on geoarchaeological investigations on the Ullafelsen representing a very important prehistorical encampment site used by Mesolithic hunter-gatherers (10.9–9.5 cal. kyr BP). In order to contribute to a better understanding of the landscape evolution of the Fotsch Valley, we here studied the close-by subalpine ‘Potsdamer Hütte Mire’ by applying radiocarbon dating as well as elemental, biomarker, compound-specific stable isotope, palynological and macrofossil analyses on bulk peat samples. The calculated age-depth model using R Bacon indicates the beginning of peat formation during the Early Holocene and shows a strongly reduced peat accumulation rate (PAR) from 170 to 121 cm depth (8.5–2.1 cal. kyr BP) and/or a striking hiatus. Results of leaf wax-derived n-alkane biomarkers as well as macrofossils and palynological indicators reflect the local presence of coniferous trees and the synchronous expansion of deciduous trees during the Early Holocene. The above-mentioned strongly reduced PAR and/or hiatus coincides with the Neolithic, the Bronze and the Iron Age, and goes hand in hand with strong changes in vegetation and an increase of micro-charcoal and black carbon. Despite age uncertainties, these changes can be explained with strongly increasing human and livestock activities in form of deforestation, domestic fires and the beginning of Alpine pastoralism. The latter is confirmed by the finding of pasture and cultural indicator pollen (Cerealia-type, Rumex, Plantago lanceolata, Poaceae) occurring since the Middle to Late Bronze Age. The oxygen isotope composition of sugar biomarkers (δ18Osugars) likely reflects the dry versus humid climatic variability associated with the Holocene climatic optimum during the Mesolithic, the Roman Age, the Late Antique Little Ice Age, the Middle Ages and the Little Ice Age.

The potential for palaeoseismic and palaeoclimatic reconstructions from Lake Tennyson, North Canterbury, New Zealand

ABSTRACT Lake Tennyson’s basin and sedimentary record were assessed for multiple branches of paleoenvironmental research. A geophysical investigation of the lake depositional setting was supported by physical and chemical analysis of multiple sediment cores. The basin reaches 60 m depth and several subaerial landforms identified were likely deposited from seismic activity. Deformed sediments and turbidites in gravity cores are attributed to one or more large (pre)historic earthquakes, and episodic grain size changes in sediment cores are related to either seismic and/or climatic/meteorological processes. A hummocky slump deposit located on the western lake bed margin is linked to widespread sediment deformation that was likely caused by movement of the Awatere Fault. Radiocarbon dating constrains the most recent major deformation event between the late thirteenth century CE and mid-twentieth Century. Folded turbidites in the stratigraphy suggest multiple sedimentary deformation episodes occurred during the last millennium. Micro-XRF elemental signatures suggest proxies of past water column mixing (windiness proxy) can be reconstructed via identification of changing redox conditions. Records from Lake Tennyson show potential for several palaeoenvironmental research applications, and combining them with basin morphostratigraphy and land-based palaeoclimate and palaeoseismic evidence can enhance understanding of environmental change in the northern South Island.

Isotope sample preparation of diatoms for paleoenvironmental research.

Isotopes in diatoms are increasingly used in palaeoenvironmental studies in both lacustrine and marine settings, enabling the reconstruction of a range of variables including temperature, precipitation, salinity, glacial discharge, carbon dynamics and biogeochemical cycling. This protocol details an optimised methodology for extracting diatoms for isotope analysis from sediment samples, using a range of chemical and density separation techniques that minimise sample loss and avoids the need for expensive equipment. Whilst designed for the extraction of diatoms for oxygen, silicon and carbon isotope analysis, additional stages are outlined for the analysis of other isotopes that are of increasing interest to the palaeo community (e.g., boron and zinc). The protocol also includes procedures for assessing sample purity, to ensure that analysed samples produce robust palaeoenvironmental reconstruction. Overall, the method aims to improve the quality of palaeoenvironmental research derived from isotopes in diatoms by maximising sample purity and the efficiency of the extraction process.

Palaeoenvironmental research at Hawelti–Melazo (Tigray, northern Ethiopia) – insights from sedimentological and geomorphological analyses

Abstract. The sites of Hawelti–Melazo in the Tigray region of the northern Ethiopian Highlands is an archaeological hotspot related to the D'mt kingdom (ca. 800–400 BCE). The existence of several monumental buildings, which have been excavated since the 1950s, underline the importance of this area in the Ethio-Sabaean period. We investigated the geomorphological and geological characteristics of the site and its surroundings and carried out sedimentological analyses, as well as direct (luminescence) and indirect (radiocarbon) sediment dating, to reconstruct the palaeoenvironmental conditions, which we integrated into the wider context of Tigray. Luminescence dating of feldspar grains from the May Agazin catchment indicate enhanced fluvial activity in the late Pleistocene, likely connected to the re-occurring monsoon after the Last Glacial Maximum (LGM). The abundance of trap basalt on the Melazo plateau, which provides the basis for the development of fertile soils, and the presumably higher groundwater level during the Ethio-Sabaean Period, provided favourable settlement conditions. The peninsula-like shape of the Melazo plateau was easily accessible only from the east and northeast, while relatively steep scarps enclose the other edges of the plateau. This adds a possible natural protective function to this site.

Diversity and distribution of lacustrine diatoms along the Trans‐Mexican Volcanic Belt

Abstract The Trans‐Mexican Volcanic Belt is recognised as a highly biodiverse zone and we present a study of diatom diversity and species distributions in its lakes. We aimed to identify diatom taxa with the highest regional occupancy, explore diversity at a regional level, identify the main variables associated with species distributions, and present weighted average optima for variables that could provide a valuable reference for future palaeoenvironmental research. We used the relative abundances of diatoms in surficial lake sediments to estimate different diversity metrics and alpha, beta and gamma diversities. Groups of lakes with similar diatom assemblages were identified by means of cluster analysis whereas canonical correspondence analysis (CCA) was used to evaluate the association between diatom composition and climatic, morphometric, hydrochemical and trophic status related variables. Weighted average optima were estimated for salinity and temperature. From a total of 184 diatom taxa, three were endemic to one or two lakes and eight had the largest regional occupancy, two of which were associated with high salinity environments (Stephanocyclus meneghinianus, Nitzschia frustulum) and the rest with freshwater conditions (Aulacoseira ambigua, A. granulata, A. granulata var. angustissima, Discostella stelligera, Fragilaria crotonensis, Achnanthidium minutissimum). Surprisingly, endemic taxa as well as those with high regional occupancy were mostly planktic or epipelic motile forms, with high dispersal potential. Our results showed 13 clusters of lakes with similar diatom assemblages, in close agreement with beta diversity which predicted the presence of 12 communities. There was high species turnover (βSIM = 0.97) and CCA showed not only that the main environmental variable defining these groups was salinity, but also that temperature, precipitation, depth, and soluble reactive phosphorus were meaningful variables. There was no evidence of an altitude–diversity pattern. This study emphasises the strong influence that climatic variables have on species distribution when relatively broad geographical areas, with large climatic gradients are analysed.

Colonists and Natives. The Beginning of the Eneolithic in the Middle Warta Catchment. 4500–3500 BC

Abstract The article presents the history of research and the latest archaeological discoveries of the Greater Poland Neolithic in the Middle Warta River catchment. I propose focusing on new areas of research that have potential but have not yet been conducted. It focuses on two social groups, the Funnel Beaker culture (FBC) and the Brześć Kujawski culture (BKC). The unsatisfactory level of knowledge about the development of these cultural communities in the region may be supplemented by recently conducted research. The discovery and excavation of the first megalithic tombs in Greater Poland, conducted with the help of LiDAR, was of great importance. Following this, more such cemeteries have been located. The re-analysis of previously excavated materials from the site in Kotowo determined that the early phase of FCB occurred around 3700 BC. A fruitful area for future study is the acquisition of unique BKC settlement evidence obtained from the site in Kąkolewo. Another important area that can supplement current understandings of cultural relations in this area is understanding the environmental background, which is to be served by the proposed palaeoenvironmental research, particularly near the cemetery in Sobota. Considering this new information will allow for a proper estimation of the role of Greater Poland in the transmission of cultural patterns that created the image of the Central European Plain in 4500–3500 BC.

High-resolution record of geochemical, vegetational and molluscan shifts in a Central European spring-fed fen: implications for regional paleoclimate during the early and mid-Holocene

Despite the increasing interest in spring-fed fens’ sediments as a palaeoenvironmental archive, their potential as high-precision climatic records is rarely used to its full extent. Here, we present a detailed early to mid-Holocene record of environmental changes in the Turtul hanging spring-fed fen, northeastern Poland, to test whether the well preserved and accurately subsampled alternating peat and tufa sediments allow us to recognise short-duration local and regional climatic changes. Our reconstructions are based on a loss-on-ignition analysis of the sediment, carbon and oxygen stable isotope values of tufa, and biotic proxies: plant macrofossil and malacological analyses. A detailed environmental reconstruction was possible due to the combination of detailed sampling (1 cm intervals) and high sediment accumulation rates. The two sediment sequences collected from the fen revealed the congruent palaeoenvironmental history; however, the temporal shift associated with the distance of the coring site from the water outflow was also apparent, stressing the need for careful selection of the coring site in palaeoenvironmental research. Peat deposition at Turtul started at 10,300 cal yr BP; however, tufa precipitation did not begin before 9250 cal yr BP. During the most active tufa deposition, from 7850 to 6100 cal yr BP, a high sedimentation rate was observed (0.11–0.25 cm yr−1). We found several abrupt and short-duration declines in carbonate deposition corresponding to climatic fluctuations recorded in geological archives from the southeastern Baltic region. The carbonate drops at 8200–8130, 7900–7850, 7400–7300, 6600–6500, 5980–5870 and 5400 cal yr BP were associated with climate cooling or drying, whereas those at 10,200–9250, 8450–8340 and 6160–6100 cal yr BP can be attributed to drying with no cooling. We conclude that the evident sensitivity of the Turtul fen to climatic shifts that emerge from our high-resolution (one sample every 17 years on average) reconstruction complements the still rare high-resolution palaeoenvironmental records in the area.

Pollen characters and their evolutionary and taxonomic significance: using light and confocal laser scanning microscope to study diverse plant pollen taxa from central India

Increasing the taxonomic resolution of fossil pollen identification and establishing the kinship and similarity among phylogenetically related plant groups are inevitable for advancing the Quaternary palaeoecological, palaeoclimatological and palaeoenvironmental research. We, in the present study, examined and determined the pollen morphological characteristics of nine plant taxa belonging to seven families from central India by a combined light microscopic (LM) and confocal laser scanning microscopic (CLSM) study. The prime object was to observe, document and describe, as well as illustrate the prevalent variation in pollen shape, size, aperture number and diameter, diameter of the polar axis and equatorial distance, as well as exine thickness and pattern (i.e. pollen wall architecture) of the studied plant taxa. Pollen identification key was developed to demonstrate variations in pollen features and delimit taxa for correct identification. Principal component analysis (PCA) suggests exine and aperture number as dominant characters, as well as hierarchical clustering analysis (HCA), applied to the pollen morphological characters of nine plant taxa to understand the variability among the taxa, and to cluster them, respectively, suggest three clusters. The cophenetic correlation coefficient also substantiates the three group of clustering. The present study has significance in taxonomy and systematics, as well as in phylogeny and evolution. In addition, the preservation potential of different pollen grains has been ascertained, based on the pollen wall architecture. The study, moreover, will improve the precise fossil pollen identification, which is critical for advancing Quaternary palaeoecology in India and also in similar tropical and subtropical areas of the globe.

Advances and Challenges in Palaeoenvironmental Studies Based on Oxygen Isotope Composition of Skeletal Carbonates and Phosphates

Oxygen isotopes are widely used in palaeoenvironmental and palaeoclimatic studies as they record variations in the precipitation temperature of biogenic carbonates and phosphates. Problems associated with the preservation state of fossils, selection of the proper temperature equation, vital effects occurring during biomineralization, habitat effects of organisms as well as salinity, bathymetry and water circulation changes limit, however, the applicability of oxygen isotopes to reconstruction of ancient environmental settings. The progress of oxygen isotope studies, temperature calculations and ambiguities of the isotope record are discussed in this paper. The same applies to the methods of retrieving reliable temperature signals and the record of water chemistry changes based on well-preserved calcareous and phosphatic fossils. Sometimes neglected importance of sedimentological and faunistic data associated with sea-level changes and salinity variations is emphasised as an important tool for refinement of the temperature trends of epeiric sedimentary basins. In addition, published case datasets and new laboratory techniques, including micro-area and clumped isotope analyses, are presented to demonstrate examples and prospective ways of extension of the scope of palaeoenvironmental research. The provided information may be used in discussion and a critical review of published oxygen isotope data and their palaeoenvironmental interpretations.

Cave and rock shelter sediments of southern Africa: a review of the chronostratigraphic and palaeoenvironmental record from Marine Isotope Stage 6 to 1

AbstractCaves and rock shelters contribute important records to local, regional and sub-continental reconstructions of environment and climate change through the southern African Quaternary. Against a backdrop of pronounced climate change, the archaeological record of the Marine Isotope Stage 6 to 1 period in southern Africa documents a remarkable time in the behavioural and technological evolution of anatomically modern humans. Significant evidence of this evolution is represented in diverse components of the sedimentary record in caves and rock shelters in the region. We present a catalogue of published caves and rock shelters in southern Africa that preserve temporally-relevant clastic and chemical palaeoclimatic proxies in order to: (1) facilitate the integration of cave and rock shelter sedimentary data into broader, regional chronostratigraphically-correlated palaeoclimatic sequences; and (2) identify possible areas and proxies that require focused research in the future. To demonstrate the complexity of the Marine Isotope Stage 6 to 1 stratigraphic record and use of palaeoenvironmental proxies, we present three case studies representing interior and coastal contexts: Border Cave, Klasies River Mouth and Pinnacle Point. These examples aptly demonstrate the challenges of these contexts, but also the opportunities for palaeoenvironmental research in southern Africa when conducted through integrated, multidisciplinary approaches. Published records of palaeoenvironmental research from cave and rock shelter sequences in southern Africa are heavily biased to the South African coastal areas and the record is temporally and spatially fragmented. However, there are interesting patterns in the chronostratigraphic record and in the distribution of sites within the context of the geology and vegetation ecology of southern Africa that require further exploration. There are also promising techniques in stable isotope analysis that can be applied to abundant sedimentary components found in the region’s caves and rock shelters, and in its museums.

2400 years of climate and human-induced environmental change recorded in sediments of Lake Młynek in northern Poland

Abstract. In the densely forested Warmia and Masuria region (northern Poland) there are many small endorheic lakes characterized by their low sedimentation rate, which makes them excellent archives of Holocene environmental and palaeoclimatic change. Lake Młynek, located near the village of Janiki Wielkie, was selected for multi-faceted palaeoenvironmental research supported with radiocarbon dates. Sediments from this lake also contain unique information about human impact on the environment, because a stronghold has been operating on its northern shore since the early Iron Age to the early Medieval period, giving the opportunity to correlate palaeoenvironmental data with the phases of human activity over the last 2400 years. During the second and third centuries BCE the lake was surrounded by a dense deciduous forest. From the first century BCE to second century CE the forest around the lake was much reduced, which can be associated with the first pre-Roman (La Tène) and Roman occupation phase evidenced by the construction of the stronghold located close to the lake. From the second up to ninth century CE gradual restoration of the forest and a decline in human activity took place, along with lake deepening and the onset of a colder and humid climatic phase which corresponded to the global cooling episode known as the Bond 1 event (1.5 ka BP). The next intensive phase of forest clearing around the lake occurred between the 9th–13th century CE as result of human activity (Middle Age settlement phase of the stronghold). Whilst this period is marked by a warming, the human impact which has transformed the landscape likely overprints any signals of climate-driven environmental changes.

9000 years of changes in peat organic matter composition in Store Mosse (Sweden) traced using FTIR‐ATR

Store Mosse (the ‘Great Bog’ in Swedish) is one of the most extensive bog complexes in southern Sweden (~77 km2), where pioneering palaeoenvironmental research has been carried out since the early 20th century. This includes, for example, vegetation changes, carbon and nitrogen dynamics, peat decomposition, atmospheric metal pollution, mineral dust deposition, dendrochronology, and tephrochronology. Even though organic matter (OM) represents the bulk of the peat mass and its compositional change has the potential to provide crucial ecological information on bog responses to environmental factors, peat OM molecular composition has not been addressed in detail. Here, a 568‐cm‐deep peat sequence was studied at high resolution, by attenuated reflectance Fourier‐transform infrared spectroscopy (FTIR‐ATR) in the mid‐infrared region (4000–400 cm–1). Principal components analysis was performed on selected absorbances and change‐point modelling was applied to the records to determine the timing of changes. Four components accounted for peat composition: (i) depletion/accumulation of labile (i.e. carbohydrates) and recalcitrant (i.e. lignin and other aromatics, aliphatics, organic acids and some N compounds) compounds, due to peat decomposition; (ii) variations in N compounds and carbohydrates; (iii) residual variation of lignin and organic acids; and (iv) residual variation of aliphatic structures. Peat decomposition showed two main patterns: a long‐term trend highly correlated to peat age (r = 0.87), and a short‐term trend, which showed five main phases of increased decomposition (at ~8.4–8.1, ~7.0–5.6, ~3.5–3.1, ~2.7–2.1 and ~1.6–1.3 ka) – mostly corresponding to drier climate and its effect on bog hydrology. The high peat accumulation event (~5.6–3.9 ka), described in earlier studies, is characterized by the lowest degree of peat decomposition of the whole record. Given that FTIR‐ATR is a quick, non‐destructive, cost‐effective technique, our results indicate that it can be applied in a systematic way (including multicore studies) to peat research and provide relevant information on the evolution of peatlands.

The Role of Palynology in Archaeoecological Research: Reconstructing Human-Environment Interactions during Neolithic in the Western Mediterranean

This paper provides an overview of the potential of palynology within palaeoenvironmental research to reconstruct past landscapes and assess the relationship between vegetation and the first farming communities. The analysis of pollen and non-pollen palynomorphs in natural records evidenced how the adoption of farming and new sedentary settlement patterns resulted in major landscape transformation on extra-local or regional scales in the Western Mediterranean, affecting sclerophyllous and riparian forests in North Corsica, Mediterranean maquis in South Corsica, and oak forests in NE Iberia. In addition, palynology has been confirmed as a relevant source of data to address the local palaeoenvironmental evolution in lakes, wetlands, and archaeological sites, providing evidence of the presence of flocks (spores of coprophilous fungi), and changes in hydrology (salinity, dryness/wetness, aquatic/palustrine phases) and in geomorphology (soil erosion indicators). Finally, the spatial analysis of pollen and NPP intra-site distribution is presented here as a valuable tool to assess the social use of space in archaeological sites. In that sense, archaeopalynology has provided detailed information about site formation processes, social use of space, and the use of plants and fungi in the site of La Draga (Girona, Spain).

Spatial distribution and environmental significance of phytoliths in the surface soil of the Xilingol Grassland in Inner Mongolia, China

Reconstruction of grassland ecosystems and their vegetation succession is an important issue in palaeoenvironmental research. Phytoliths and pollen are two common proxies for palaeovegetation reconstruction, and their importance can be evaluated based on investigations of the relationships between modern vegetation and phytolith/pollen assemblages in surface-soil samples. The correlations between phytolith assemblages and environmental variables were analysed based on 34 surface-soil samples from the Xilingol Grassland, Inner Mongolia, North China, and a palynological analysis was carried out on the same samples, enabling a comparison between their sensitivity to vegetation and climate change. The results show that the phytolith assemblages mainly consist of blocky and rondel phytoliths, while other short-cell phytolith types, such as saddle and bilobate types, are scarce. The pollen assemblages were characterised by a high abundance of Artemisia and Amaranthaceae. Canonical correspondence analysis (CCA) indicated that the most important environmental factors affecting the distribution of phytoliths are altitude and latitude, while the mean warmest monthly temperature (MWMT) and altitude were the most significant environmental factors affecting the distribution of the pollen assemblages. CCA of the phytoliths and pollen assemblages separated both samples into two groups: broadleaf forest/scrub and steppe/meadow groups, but it appeared that phytoliths were more sensitive in arid grasslands. This case study could be used as a baseline for interpreting fossil phytolith/pollen assemblages from the grasslands of Inner Mongolia and indicates that multiproxy analysis of the same samples can provide reliable information on palaeovegetation and palaeoclimate reconstruction.

Staining of subfossil chironomid head capsules: a method for improving the extraction process from lake sediments and peat

Subfossil chironomids are regarded as a useful biological proxy for palaeoenvironmental research, but picking chironomid head capsules from aquatic sediments is extremely time-consuming. This is often the case for finding and isolating small head capsules from the deflocculated sediment. In this study, two stains (aniline blue and cotton blue) were used to dye chironomid head capsules in lake and peat sediments to improve the traditional pretreatment method and boost the picking efficiency. The results suggested that: (1) there were sharp contrasts between chironomids and residues after staining, which could shorten picking time for both lake and peat samples; (2) different parts of head capsules showed distinctive colour in stained samples and thus facilitated identification and taxonomy of subfossil chironomids; (3) the dyeing effects of two stains were comparable and no significant effect of staining on chironomid composition has been observed compared with unstained samples. This study demonstrates that aniline blue and cotton blue stain can promote picking efficiency of subfossil chironomids, and can be widely applied to pretreatment of sedimentary chironomids in palaeoenvironmental studies on lakes and peatlands.

Coastal peat-beds and peatlands of the southern North Sea: their past, present and future.

Peat layers are well represented in the Holocene coastal deposits of the southern North Sea and provide evidence as to the extent and nature of the fens and bogs that occupied the region in the mid and late Holocene. While natural processes contributed to their demise, without human interference extensive areas of peatland would remain. We review the characteristics of the vegetation of these peatlands along with the processes that influenced their development. Spatial and temporal trends are explored through the use of palaeogeographic maps from three areas: the East Anglian Fenland, the Romney Marsh area and the Netherlands. The palaeoecological evidence indicates that eutrophic vegetation promoted by rising relative sea level (RSL) dominated in the mid Holocene, with a trend towards the development of oligotrophic and ombrotrophic vegetation in the late Holocene as the rate of RSL rise declined. Nevertheless, areas of eutrophic vegetation appear capable of long-term stability with areas of fen woodland and herbaceous fen persisting at some locations for several thousand years in the mid and late Holocene. Areas of active peat growth in the region are now largely confined to small remnants within agricultural settings. To retain their characteristic biodiversity these remnants have been managed using traditional practices, although their small size and fragmented distribution limits their biodiversity value. Biodiversity concerns and the ecosystem services peatlands provide, notably carbon sequestration and flood attenuation, underlie recent restoration projects. These efforts are likely to receive additional impetus as a consequence of rising water levels, given projected rates of RSL rise. Future large-scale restoration can be informed by a greater understanding of the processes that formed and sustained coastal peatlands in the past. We identify advances in palaeoenvironmental research that could enhance restoration efforts and help maximise the ecosystem services delivered through such projects.

Investigating lake sediments and peat deposits with geophysical methods - A case study from a kettle hole at the Late Palaeolithic site of Tyrsted, Denmark

Kettle holes are common ice decay features in formerly glacial landscapes like those in Southern Scandinavia and Northern Germany. Here the kettle holes are represented either as dry depressions, wetland areas or lakes. However, the majority of these features are silted and part of the present farmland. We investigated a small kettle hole at Tyrsted, near the township of Tyrsted, south of Horsens (Denmark) with the aim to determine the extension and depth of this feature using geophysical methods. A former excavation at Tyrsted carried out from the Horsens Museum in 2017 at a neighboring site revealed Late Palaeolithic flint of the Bromme type and worked reindeer antlers. This connection in a Late Glacial horizon is unique not only in a Danish context and it can help to improve and clarify the dating of the Bromme culture. We used ground penetrating radar (GPR), electromagnetic induction (EMI) and electrical resistivity tomography (ERT) to estimate the extension of the kettle hole (~16 m × 25 m). Shear wave reflection and refraction seismics (SH Seismics) were able to detect the bottom sediment of the former lake at about ~5 m depth. Furthermore, a seismic event at about 1.30 m depth is visible which can be associated to the transition between the Allerød and Younger Dryas sediment making the detection of the Bromme horizon possible. After the non-invasive investigation, a location for an open excavation has been chosen in a way to groundtruth the geophysical results allowing the direct comparison with the stratigraphy. These results allow the archaeologists to identify key excavation areas focused on the investigation of the Allerød and Younger Dryas layers in a way to improve the dating information about the Bromme horizon collected so far. Furthermore, geophysical investigations together with excavations will enable the archaeological and palaeoenvironmental research groups to search large scale palaeolandscapes for these very rare, but highly important finds.

Rethinking the Disappearance of Microblade Technology in the Terminal Pleistocene of Hokkaido, Northern Japan: Looking at Archaeological and Palaeoenvironmental Evidence

Archaeological research, for several decades, has shown that various microblade technologies using obsidian and hard shale appeared and developed from the Last Glacial Maximum to the terminal Pleistocene (Bølling–Allerød–Younger Dryas) in Hokkaido, Northern Japan. It is well accepted that microblade technology was closely related to the high mobility of foragers to adapt to harsh environments. Recent archaeological and palaeoenvironmental evidence from Hokkaido demonstrates that the disappearance of microblade technology occurred during the terminal Pleistocene, influenced by a wide range of factors, including changes in landscape, climate, subsistence and human populations. The goal of this paper is to provide an overview of the current state of research on the process and background of the disappearance of microblade technology and to discuss prospects for future research. This paper will (1) review palaeoenvironmental research in Hokkaido on changes in climate and biological composition from the terminal Pleistocene to the initial Holocene; (2) survey changes in the technological adaptations and resource use of humans based on the archaeological evidence; and (3) discuss how the abrupt fluctuations of climate that occurred in the terminal Pleistocene affected human behaviour and demographics in Hokkaido.

Deeper Than Expected: The Finding of a Remarkable Ancient Harbour at Gadir/Gades and an Exceptional Sedimentary Archive (Cádiz, Southern Spain)

Geoarchaeological cores were retrieved in the centre of the old “Bahia-Caleta” palaeochannel located between the Erytheia and Cotinusa islands in the former Cadiz archipelago, in present-day southern Spain. The unprecedented coring depth (~ 35–50 m) allowed us to identify the bottom of a Phoenician–Punic and Roman harbour. Located at 20–40 m b.s.l. in the sedimentary sequence, silty sand deposits reveal a deep semi-protected shelter with abundant ceramic and archaeobotanical findings. Based on these new results, the palaeotopography of the islands of Cadiz is reinterpreted, demonstrating the presence of a harbour accessible from the west and possibly from the east until (at least) the Roman period. This major discovery opens meaningful perspectives for archaeological, geomorphological and palaeoenvironmental research.

Tracing the Networks of Past Societies in Palaeoenvironmental Research

AbstractHistorical societies reshaped their environment in various ways; by clearing forest, cultivating crops, mining, and modifying waterways. Evidence of these activities persists in palaeoenvironmental archives, which represent comprehensive histories of human activity in a landscape. Analysis of settlement networks across landscapes is another common approach to investigating how past societies operated, but these analyses rarely incorporate palaeoenvironmental data. Here, we combine these two data sources to examine past socio‐political relationships in a society that experienced disruption and transformation. Applying network analysis, and using settlement histories built from palaeoenvironmental proxies for occupation and land use, this paper reconstructs population dynamics at several key nodes (cities) within the Khmer kingdom of Southeast Asia, before and after the climate stress and political upheaval of the 14th–15th centuries ce. Our results reveal how the Khmer city network transformed across space and the nature of the relationships that existed within the network prior to its disruption.