Search Results (344)

This study presents a meta-analysis of relatively high-resolution paleohydrological proxies derived from geological archives in Sardinia and in the Italian Peninsula–Sicily over the last 2000 years, with particular emphasis on the Medieval Warm Period (MWP) and the Little Ice Age (LIA). The investigated climate proxies, ranging from annual-decadal to centennial resolution, include terrestrial and marine sediment cores, glaciers, pollen spectra, speleothems, lake-level fluctuations, as well as sedimentary and geomorphological inventories. Such datasets were analyzed through holistic and stratigraphic approaches along West–East and North–South transects across the central Mediterranean. Limited temporal resolution and incomplete stratigraphic continuity of several paleoclimatic records from the investigated regions thwart full reconstructions of paleohydrological trends. Nevertheless, the presented meta-analysis has enabled: (1) the recognition of reliable paleoclimatic correlations between the two regions, which exhibit long-lasting anti-phase hydroclimatic trends (wetter conditions in Sardinia and drier conditions in central Italy during the MWP, with the opposite pattern during the LIA); and (2) the identification of the North Atlantic Oscillation (NAO) as the primary driver of these paleohydrological variations. The significance of this anti-phase pattern is discussed in the context of the North–South and West–East climatic dipoles identified in the Mediterranean region during the middle to late Holocene. Furthermore, we assessed the potential of the investigated paleohydrological network to: (1) compare reconstructed hydrological patterns with mean temperature and precipitation records derived from empirical and model-based climate reconstructions in southern Europe and the Mediterranean; and (2) identify gaps in data coverage that currently limit our understanding of high-resolution spatiotemporal hydrological variability and dynamics.The hydroclimatic pattern in Sardinia and in the Italian Peninsula–Sicily has exhibited marked spatio-temporal divergences, with major hydroclimatic transitions coincident with well-known solar minima over the last millennium, thus suggesting a possible cause-and-effect relationship. The interpretations presented in this study provide a framework for understanding how changes in the paleoclimatic variability of water resources may have influenced different regions of Italy since the Middle Ages, potentially affecting societal transitions as well as historical and socioeconomic dynamics. Comparison of the multidecadal-to-centennial reconstructions of paleohydrological patterns is presented for both areas, pending the development of new, higher-resolution, and more precisely dated proxies from the Italian records. Their importance is emphasized in order to improve reconstructions of past climate variability and to enhance assessments of future climate trajectories. Full article

Research in quantitative paleohydrology shows that a phase of very high river discharge on the northern Eurasian plains in the late Pleniglacial (about 18–14 ka BP) was followed by a much less studied phase of reduced discharge and small-channel formation. To characterize this morphohydrological metamorphosis, we investigated the morphometry of small meandering paleochannels on floodplains at 132 river-valley sites in the Volga basin. On average, the widths and meander wavelengths of these paleochannels are approximately half those of modern channels. The ages of the paleochannels range from 10 to 4 ka BP. The hydrological regime of small mid-Holocene meandering rivers was reconstructed using morphometric relationships, principally the power-law relationship between bankfull channel width and mean maximum flood discharge and the relationship between maximum discharge and contributing basin area. The mean reconstructed daily maximum runoff depth for small catchments in the Volga basin during the snowmelt period in the mid-Holocene was about 5 mm/day, approximately half the modern value. The ratios between mean annual and mean maximum runoff depths in the mid-Holocene were estimated from modern regional analogues of the ancient climate, using climate models for the 6 ka BP time slice. Annual river runoff depths in the Volga basin in the mid-Holocene were then calculated from these analogue ratios and the daily maximum runoff depths. The mean annual runoff depth in small catchments was about 100 mm, almost half the current runoff in the Volga River basin. The annual Volga River runoff volume in the mid-Holocene was approximately 132 km³, compared with the current value of 250 km³. This decline in river runoff in the Volga basin resulted in a low stand of the Caspian Sea in the early–middle Holocene, with a calculated potential sea level of −65 to −79 m abs. Full article

Karst poljes in the Dinaric karst are widely infilled with Quaternary sediments. In the Bribir–Ostrovica karst polje, these sediments were investigated using geomorphological mapping and multiproxy analysis of lake sediment cores, including grain size, mineralogical, total organic and inorganic carbon (TOC, TIC), and ostracod analyses, coupled with radiocarbon dating. A key sediment core (OSP-3) recovered a ~470 cm long sedimentary sequence dating back to 13,200 cal yr BP. The floodplain to wetland environment occurred at the Late Pleistocene to Holocene transition (ca. 12,100 cal yr BP), evident by the first appearances of ostracods and an increase in TOC. More stable lake conditions prevailed between 9600 and 7200 cal yr BP, with dominant carbonate deposition and abundant ostracods. During the Middle and Late Holocene, increased clastic input and reduced ostracod presence indicate a shallow, dynamic water body influenced by erosion and periodic flooding. Lake sedimentation was strongly controlled by local karst topography, with a maximum lake depth of ca. 6 m. The Bribir–Ostrovica paleolake represents a rare terrestrial Holocene paleoenvironmental record from the Dinaric karst of the eastern Adriatic coast and provides valuable context for interpreting the nearby Neolithic archaeological site of Krivače as a lakeside settlement. Full article

Determining the relative impacts of climate variability and human activities on vegetation dynamics remains a central theme in paleoecological research. In climate transition zones like the southeastern Marmara region, isopollen maps are important because they allow for the evaluation of spatially diverse pollen records within an integrated regional framework. The aim of this study is to present a spatially holistic reconstruction of Late Holocene vegetation change in the southern Marmara region using isopollen maps based on fossil pollen records obtained from Manyas, Iznik and Sapanca lakes. Isopollen maps were created for five time periods, approximately 2600, 2000, 1250, 800 and 400 yr BP, representing major climatic and historical phases of the Late Holocene, and the spatial distribution patterns of the major tree and herbaceous taxa were reconstructed. The results demonstrate the presence of a continuous west–east variability in the region’s vegetation structure, reflecting the transition between Mediterranean and Black Sea climate regimes. However, the temporal variation patterns show that vegetation responses cannot always be directly explained by climatic phases. In particular, Artemisia highlights the persistence and local expansion of open-area vegetation, reaching approximately 24% of the study area to the present day. Given the region’s long history of settlement, these findings indicate that vegetation dynamics during the Late Holocene were shaped by the combined effects of climatic changes, local environmental conditions and human activities. Therefore, the study emphasizes the importance of spatially integrated approaches in paleoecological reconstructions. Full article

The Abuduo Fault is a Holocene left-lateral strike-slip fault located on the eastern margin of the Tibetan Plateau, potentially connecting eastward with the Garzê–Yushu Fault. Due to its high-altitude setting, this fault remains poorly studied, and knowledge of its detailed surface geometry and slip rate is still insufficient. Using GF-7 and other multi-source remote sensing data, field surveys, semi-automatic offset extraction software, and radiocarbon (¹⁴C) dating, we determined the fault’s fine surface geometry, offsets, and slip rate. The results show that the fault can be divided into western, central, and eastern segments based on geometric discontinuities. The central segment consists of four right-stepping en echelon faults. The western and central segments are separated by a left-stepping compressional ridge with a step-over width of ~3.1 km, while the central and eastern segments are separated by a right-stepping pull-apart basin with a step-over width of ~9.4 km. Offsets generally increase from west to east. The western and central segments may exhibit stronger Late Quaternary activity, but this understanding remains to be further validated. Based on offset measurement and the dating of a typical offset gully, the Holocene slip rate of the western segment is estimated at 2.5–2.8 mm/yr. Full article

The Central Basin Fault Rift (CBFR) is a key area for studying deep-sea sedimentation and paleoclimate, yet its sedimentary process and provenance and their links to geological and climatic changes remain poorly understood. This study therefore conducted systematically sedimentological, mineralogical and geochemical analyses of sediments in core ZK06 from the CBFR to address the above question. The results show that the sediments are dominated by silt and clay, with multiple graded rhythms related to gravity flows. Provenance analysis shows that the sediments are composed primarily of proximal andesitic volcaniclastic detritus, with additional Asian aeolian dust and minor authigenic components. It is recognized that the proportion of Asian aeolian dust increases from the lower to medium part of the sediment sequence but decreases in the upper part, which may correspond to the input history of Asian aeolian dust in the West Philippine Basin during the late Pleistocene to Holocene. This study therefore provides not only new insights into sedimentary processes and the provenance of sediments but also the input history of the Asian aeolian dust in central CBFR. Full article

Fire plays an important role in shaping forested ecosystems around the globe. Unlike many other fire-driven forest types, our understanding of pre-settlement fire behavior in quaking aspen (Populus tremuloides) systems is limited. To better understand the frequency and severity of fires in a putatively stable quaking aspen forest, a small, key watershed was selected for sediment coring to reconstruct fire history, vegetation change, and climatic variability. The study aim was to explore the fire–climate–vegetation linkages in an aspen-dominated catchment. For the past ~4000 years this basin has been dominated by quaking aspen but also subalpine fir (Abies lasiocarpa), and their relative composition has shifted inversely over this period. Large, stand-replacing fires occurred, on average, every ~178 years, with individual fire-free intervals ranging from 132 to 323 years. The occurrence of fire was not related to climatic conditions as characterized by either cool-season or warm-season moisture availability (drought proxies). Rather, fire occurrence was most strongly related to fuel accumulation associated with the predictable successional shift in species dominance from quaking aspen to subalpine fir. Unlike in climate-limited systems where managers have little control over fire occurrence due to climatic conditions (e.g., drought), fuel-limited systems are controlled from the bottom up, where the explicit reduction or redistribution of long-term fuel buildup is an effective approach to reducing the likelihood and/or effects of fire in the short-term. Full article

The occurrence of Vulpes corsac in the Late Pleistocene of Europe is primarily supported by a limited number of uncertain records, many of which require revision. More reliable evidence derives from localities in Bohemia and Ukraine. The species’ history is particularly well documented in Ukraine, which also preserves the only Holocene occurrences of V. corsac in Europe, and where it persists in the eastern regions to the present day. To this record we now add the first locality from Poland, identified in Rogóżka Cave (Sudety, Silesia). It appears that Vulpes corsac was never abundant in Late Pleistocene Europe. Confirming its presence requires careful taxonomic analysis, as its rare remains must be distinguished from those of Vulpes vulpes and Vulpes lagopus, which are far more common in Late Pleistocene and Holocene assemblages. Full article

Understanding the extent to which anthropogenic activity shapes vegetation dynamics is a central challenge in palaeoecology. In the Eastern Mediterranean, pollen-based studies have traditionally identified human impact through qualitative interpretations of anthropogenic indicators, particularly within the framework of the Beyşehir Occupation Phase (BOP). However, proxy-based quantitative comparison of anthropogenic signals across multiple sites remains limited. This study compiles pollen datasets from multiple lacustrine records across Anatolia (Türkiye) to construct a regional multi-site dataset and evaluates anthropogenic influence using a quantitative BOP period anthropogenic taxa integrated with Principal Component Analysis (PCA). The relative representation of pollen indicators enabling the determination of anthropogenic effect was evaluated using a composite pollen index based on Olea, Juglans, Plantago lanceolata-type, Cerealia and Rumex acetosa-type taxa. The results reveal substantial spatial variability in anthropogenic signals, with combined pollen percentages ranging from less than 1% to 16% among lakes. PCA results show clear inter-site differentiation, with the first two components explaining 42.94% and 21.95% of the total variance, respectively. In particular, Olea emerges as the most influential indicator, strongly contributing to the primary ecological gradient. These findings provide a proxy-based quantitative extension of the traditionally qualitative BOP concept and show that selected anthropogenic pollen indicators are spatially heterogeneous across Anatolian lake records. By integrating a composite anthropogenic index with multivariate analysis, this study offers a robust and transferable framework for comparing human–environment interactions across different regions and ecological settings. Full article

Benthic foraminifera are widely used as indicators of marine environmental conditions due to their sensitivity to ecological changes and their excellent preservation in sediments. In this study, benthic foraminiferal assemblages from a sediment core collected in the central Yellow Sea were investigated to document faunal composition and examine temporal changes since the Late Pleistocene. A total of 54 benthic foraminiferal species belonging to 33 genera, 25 families, seven orders, three classes, and one phylum were identified. Among them, 12 species are newly recorded in Korean waters, reflecting the current incompleteness of regional faunal inventories and the importance of detailed taxonomic studies. The assemblages exhibit distinct stratigraphic variations. The lower interval (>30 ka) is characterized by low-diversity assemblages dominated by taxa commonly associated with marginal marine environments. The middle interval (ca. 20–25 ka) shows the occurrence of taxa typically reported from boreal to subarctic environments, suggesting changes in environmental conditions during the Last Glacial Maximum. In contrast, the upper interval (Holocene) is marked by increased species diversity and the dominance of taxa characteristic of normal marine shelf environments. These assemblage changes are interpreted as reflecting long-term responses of benthic communities to sea-level fluctuations, sedimentary conditions, and regional oceanographic variability in the Yellow Sea. In particular, the development of fine-grained deposits in the Central Yellow Sea Mud (CYSM) and the establishment of stable marine shelf conditions during the Holocene likely played important roles in shaping benthic habitats. This study provides new baseline data on benthic foraminiferal diversity in the Yellow Sea and demonstrates the potential of these assemblages as useful, though indirect, indicators for reconstructing past environmental changes. The results highlight the importance of integrating detailed taxonomic analyses with stratigraphic records to improve our understanding of marine biodiversity and paleoenvironmental variability in marginal seas. Full article

This study presents a high-resolution, multi-proxy palaeoenvironmental reconstruction of the Tövises fen at Pocsaj, Hungary, utilising lithostratigraphical, geochemical, malacological, and palynological analyses supported by radiocarbon dating. The sedimentary sequence documents the transition from a Late Glacial fluvial system (c. 19,000–16,000 cal BP) to a cut-off meander and subsequent oxbow lake, eventually evolving into a peat-forming fen. Malacological and palynological data reveal the co-occurrence of cold-tolerant Late Pleistocene elements and the early appearance of thermomesophilous taxa at the onset of the Holocene. This suggests that the favourable microclimate of the adjacent loess-covered high bank and the humid alluvial plain functioned as a cryptic refugium for temperate broad-leaved trees and associated fauna during the Late Glacial. Anthropogenic impact is traceable from the Mesolithic, characterised by Corylus management, intensifying through Neolithic agriculture to a peak during the Roman Imperial Period. Geochemical markers in the upper peat sequence reflect increased biomass and medieval habitation, while recent malacofaunal shifts indicate progressive desiccation. Despite modern drainage attempts, the Tövises fen remains a biodiversity hotspot of high conservation value, preserving relict wetland communities. Full article

This article analyzes the information provided by the sedimentary sequences of 29 lakes in central Mexico, 10 of which are currently paleolakes. During the Late Quaternary, the lakes of central Mexico experienced environmental changes driven by global and local climatic and geological processes, showing regional trends of wet and dry periods. Paleoenvironmental reconstructions are based on the use of 20 indicators, including diatoms, pollen, geochemistry, mineralogy, granulometry, magnetic susceptibility, and isotopes. Seven major episodes are recognized in the historical evolution of the lakes of central Mexico: i. Late Miocene–Pliocene: A period that includes the formation of large lakes in central Mexico by volcano tectonic activity under a regime of continuous humidity. ii. Pleistocene–Drought and climatic variability of the interglacial period. iii. Drying and successive lacustrine transgression during the Last Glacial Maximum. iv. Spatial climate variability in the Heinrich 1 period. v. Lake regression and expansion of terrestrial vegetation in the Bølling–Allerød period. vi. Transgression of lakes of central Mexico during the Younger Dryas and mid-Holocene periods. vii. Late Holocene: A period that includes lake desiccation influenced by the impact of human activities. The analysis of the data allows us to propose six challenges for the scientific community in future research of central Mexico. Full article

Coastal regions played a key role in the emergence of Early Neolithic cultures. Fluctuating sea levels shaped prehistoric human migration, settlement patterns, and adaptation strategies. The lower reaches of the Min River in Fujian were a major centre of activity. During the Middle to Late Neolithic, marine communities such as the Keqiutou (6500–5500 cal. a BP) and Tanshishan (5500–4300 cal. a BP) cultures flourished. However, the scarcity of earlier remains has limited understanding of Early Neolithic life before 8000 cal. a BP. We dated stratigraphic layers at the newly excavated Niutoushan site using radiocarbon dating and optically stimulated luminescence (OSL). OSL results indicate the site’s Neolithic culture layer between 9.3 ± 0.7 ka and 8.1 ± 0.5 ka, with radiocarbon dates clustering around 8300–7000 cal. a BP. Based on the younger bounds of the dating results and kernel density estimation, the Neolithic remains at the site are dated to approximately 8000–7000 cal. a BP, identifying Niutoushan as one of the earliest Neolithic sites in the region. Combined with sea-level reconstructions, the findings suggest that the rapid Early Holocene sea-level rise drove human migration along China’s eastern coast before 8000 cal. a BP. The Niutoushan culture was influenced by Neolithic cultures from northern coastal regions and potentially by those located to its south across the exposed Taiwan Strait from the Last Glacial Maximum to the Early Holocene. This points to complex interactions among Early Neolithic cultures in both northern and southern coastal China, warranting further investigation for validation. Full article

Glacial ice cores are evidence of past environmental conditions through gases and particulate matter trapped within the drilled material. The Central Andes in the South American region are highly sensitive to climate changes; a long record of temperature and precipitation variability can be found in relation to massive ice caps. Available oxygen isotope data from three glacial ice cores from Nevados Sajama, Huascaran and Illimani (Peru and Bolivia) drilled over the last decades in the Central Andes are revisited to investigate climate variability over the past seven millennia, a period characterized globally by remarkable climatic stability. The analysis revealed statistically significant millennial- and centennial-scale periodicities in the isotope records ranging from centennial to millennial timescales. These cycles have periods of 1.3, 0.87, 0.67, 0.46, and 0.25 kiloyears (ka). A series of regional temperature minima and maxima are also identified. This variability in the Andean climate during the mid and late Holocene is interpreted as being strongly controlled by changes in solar activity, in particular, the forcing of “grand solar minima” is recognized. Likewise, less frequent climate changes could be correlated with Bond cycles and increased or decreased activity of the Atlantic Meridional Overturning Circulation (also known as AMOC or the thermohaline), among other climate forcings such as volcanic activity. Full article

The Daliangshan Fault Zone (DLSFZ) constitutes a key segment of the Xianshuihe–Xiaojiang Fault System (XXFS) and exerts fundamental control on the eastward extrusion of the Sichuan–Yunnan Block (SYB). In this work, we present new slip rate determinations at three key sites (Tekoujiagu, Yeer, Damulo) along its middle-southern segments using UAV-based high-resolution topography and OSL dating. Results yield late Quaternary slip rates of 4.5 ± 1.4, 3.7 ± 1.1, and 5.5 ± 1.0 mm/a, respectively. Combined with previous data, the slip rate is 1.5–3.1 mm/a in the northern segment, 1.36–4.3 mm/a in the middle and 2.5–4.5 mm/a in the southern segment, which exhibits a spatial pattern of “higher in the south, lower in the north, with transition in the middle”. Temporal evolution suggests increased slip rates from the Late Pleistocene to Holocene. These characteristics indicate that the DLSFZ is a heterogeneous deformation system, where strain focusing on the southern segment reflects the block’s eastward escape constrained by the rigid Sichuan Basin (SB). Thus, the DLSFZ, especially its southern segment, serves as a key structure regulating crustal extrusion at the southeastern margin of the Tibetan Plateau (TP). Full article