Glacial records worldwide increasingly indicate that mountain glaciers and parts of continental ice sheets reached their maximum extents asynchronously throughout the Late Pleistocene, often before the global Last Glacial Maximum (LGM; 26-19 ka) during Marine Isotope Stage 2 (MIS 2). Local glacial maxima throughout MIS 4 and MIS 3 are usually attributed to regional paleoclimate dynamics. The role of topography in controlling pre-LGM ice culminations remains less explored, despite its recognized influence on glacier dynamics. To address this gap, we applied a combined geochronological and numerical modeling approach to two paleoglaciers of the western European Alps: the Dora Baltea (DB) and Ticino-Toce (TT) glaciers. Our dating results show that the DB and TT glaciers reached their maximum extents asynchronously, during MIS 3 and MIS 2, respectively. Because the DB and TT glaciers occupied neighboring catchments, their millennial-scale asynchrony in Late Pleistocene dynamics is unlikely to reflect climatic differences, but more probably derives from topographic controls. Our modeling shows that the higher hypsometry, steeper relief, and shorter valley length of the DB catchment lowered the climate-forcing threshold for extensive ice advance, allowing the DB glacier to build its piedmont lobe under moderate MIS 3 cooling, unlike the TT glacier. Moreover, preexisting prominent moraines likely limited the MIS 2 DB glacier advance. Our results highlight the key role of topography in driving asynchronous ice maxima and call for caution when using ice-marginal moraines and related glacial reconstructions as paleoclimate proxies.

The quality of the numerical age estimates used to establish the eruption chronology of a volcanic field is a critical control on the dependability of temporal hazard assessments. However, researchers involved in hazard assessment and modelling may be unfamiliar with dating methods and their complexities, which are needed to assess the quality of published ages. This paper aims to increase the awareness regarding the quality of geochronological data by providing brief introductions to the principles and applications of the dating methods applicable to Quaternary volcanism. The numerical dating methods included in this review are as follows: 40K / 40Ar and 40Ar / 39Ar dating, radiocarbon dating, uranium-series-related dating, cosmogenic nuclide exposure dating, and luminescence dating, as well as tephrostratigraphy and annual layer counting. First, the physical phenomena utilised by each method to provide age estimates are presented and then concerns related to the application of these methods are discussed, including necessary calibration steps and possible sources of error. This is followed by examples of the application of each of the methods. Die Qualit & auml;t numerischer Altersabsch & auml;tzungen, die f & uuml;r zeitliche Einordnung von Ausbr & uuml;chen eines Vulkanfeldes genutzt werden, spielt eine kritische Rolle f & uuml;r die Zuverl & auml;ssigkeit der zeitlich-aufgel & ouml;sten Gef & auml;hrdungsbeurteilung. Oft fehlt Forschenden, die in die Gef & auml;hrdungsbeurteilung und -modellierung involviert sind, ein eingehendes Verst & auml;ndnis f & uuml;r die genutzten Datierungsmethoden und deren Komplexit & auml;t. Dieses Verst & auml;ndnis ist jedoch Voraussetzung, um die Qualit & auml;t publizierter Alter einsch & auml;tzen zu k & ouml;nnen. Die vorliegende Arbeit soll das Bewusstsein bez & uuml;glich der Qualit & auml;tsfaktoren geochronologischer Daten sch & auml;rfen, indem die Prinzipien und Anwendungen von Methoden zur Datierung quart & auml;ren Vulkanismus zusammenfassend vorgestellt werden. Hierbei handelt es sich um Datierungsmethoden mittels 40K / 40Ar und 40Ar / 39Ar, Radiokohlenstoff, Uranzerfallsreihen, kosmogener Nuklide und Lumineszenz, sowie Tephrastratigraphie und Z & auml;hlung von Jahreslagen. Zuerst werden die physikalischen Hintergr & uuml;nde der einzelnen Methoden vorgestellt. Im Anschluss werden Probleme bei der Anwendung diskutiert, inklusive notwendiger Schritte zur Kalibrierung und potentielle Fehlerquellen diskutiert und Anwendungsbeispiele vorgestellt.

This study investigates the role of various communities in the alluvial fan of the Murghab River during the Middle and Late Bronze Age (2400-1500 BCE), focusing on how environmental and hydrological characteristics influenced settlement patterns and agricultural practices. While previous research has examined the ancient Murghab alluvial fan on a broad scale, this study aims to disentangle local-scale forms of agricultural and water management responses to climate variability. As the region became increasingly arid during the 2nd millennium BCE, communities exhibited varied responses across different micro-ecozones. Modern ethnographic comparisons suggest that environmental changes can have different impacts on groups within the same landscape based on their strategies and social characteristics (e.g., small versus larger groups). This dynamic also seems to be mirrored in the human-water relationship and site distribution in the Murghab region during the Bronze Age. With a holistic approach that includes remote sensing reconstruction of the hydrological system, archaeological surveys, geoarchaeological investigation, and OSL analysis of the ancient fluvial system, we explore the responses of local communities during the landscape and social transformations of the 2nd millennium BCE. By focusing on two small-scale areas (Togolok and Ojakly), we discover that urban areas such as Togolok exhibited clustering around selected water channels, which facilitated good water management while increasing crop production and population wealth. In contrast, rural areas adopted decentralized, small-scale cultivation and an increased pastoralism to cope with aridity and hydrological instability. Ultimately, this study provides novel insights into the importance of small-scale investigations of local economic and social organizations. These findings contribute to disentangling broader narratives of economic and social resilience in the Murghab region during the Bronze Age.

Palaeochannel systems are characteristic of alluvial plains across large parts of the Australian continent, but their evolution and modes of formation are still only partly understood. In this study, the fluvial landscapes of the upper central Murray River, and the lower Goulburn River were assessed by mapping palaeochannel remnants and fluvial terraces using high-resolution digital elevation models. This allowed for a classification of terrace and palaeochannel systems based on morphology and relative elevation above the river. Investigated river reaches across both river systems show similar relative terrace levels and related palaeochannel remnants. The produced maps allow for a better assessment of palaeochannel activity phases, however, an extensive investigation of palaeochannel and terrace chronology is needed for a better understanding of the landscape evolution and to make a statement about synchronicity of fluvial activity in these river systems.Highlightsthe fluvial landscapes of the upper central Murray River, and the lower Goulburn River were assessed by mapping palaeochannel remnants and terraceshigh-resolution digital elevation models allowed for a distinct classification of geomorphic featuresboth the Murray and Goulburn river reaches show similar relative terrace levels and related palaeochannel remnantsthe produced maps provide a foundation for further geomorphological, sedimentological, palaeohydrological, and chronological investigations to ultimately understand the drivers of these palaeochannel systems

Throughout the Pleistocene, valley glaciers repeatedly advanced into the forelands of the European Alps. However, the corresponding geological record is highly fragmentary and the regional glaciation history, especially prior to the last glacial maximum, is still poorly documented. We explored the archives of the Lower Aare Valley in the confluence area of the Aare river with Reuss and Limmat, focusing on the overdeepened Gebenstorf-Stilli Trough. In four scientific boreholes, ∼350 m of drill cores were recovered, and complemented with investigations of outcrops and reflection seismics in the nearby glaciofluvial Habsburg-Rinikerfeld Palaeochannel. The integrative interpretation of these data provides new insights into the local landscape evolution: We identified two generations of glacial basin infill in the Gebenstorf-Stilli Trough that are overlain by glaciofluvial gravels, and two distinct glaciofluvial gravel bodies in the neighboring paleochannel. In this specific local setting, gravel petrographic compositions and their statistical analysis prove to be powerful tools to identify inputs from the confluent catchments, to aid in lithostratigraphic classification, and to interpret the depositional and landscape histories. We suggest that it is mainly the penultimate glaciation, characterized by three separate ice advances, that shaped the present-day study area, and whose deposits are preserved in the Middle Pleistocene archives.

Geochronological constraints from glacial sedimentary deposits and landforms worldwide indicate that ice maxima occurred asynchronously throughout the Late Pleistocene1, often before the global Last Glacial Maximum2 (LGM; Marine Isotope Stage, MIS 2). Within the European Alps, the work of Gribenski et al. (2021)3 recently shed light on such pre-LGM (MIS 4 and late MIS 3) ‘local’ ice maxima in the western Alps, pre-dating the ice culmination in the central northern and southern Alps4, 5. This asynchrony is interpreted to result from changes in the atmospheric circulation pattern over the North Atlantic3. However, more data are needed to further corroborate this hypothesis and increase our understanding of the paleoglacial and paleoclimate dynamics of the western Alps. The Ivrea Morainic Amphitheatre (IMA; western Italian Alps) is a promising site to investigate the potential asynchrony of Late Pleistocene glaciations. This extensive end-moraine complex was built by the cyclic Quaternary expansions of the Dora Baltea glacier in the southern Alpine foreland. However, the available geochronological data6, 7 are too limited to quantitatively attribute each sub-system of moraines to different glacial advances. The present work aims to provide new chronological constraints to the innermost glaciogenic succession of the IMA. To this aim, luminescence dating is applied on proglacial glaciolacustrine and glaciofluvial deposits associated to different stages of ice advance. The obtained chronology (ca. 30 samples) provides new insights into the Late Pleistocene glacial history of one of the largest morainic amphitheatre in the European Alps, contributing to the ongoing discussion on asynchronous paleoglacial dynamics during this period. References [1] Doughty et al., 2021, Quaternary Science Reviews 261. [2] Hughes et al., 2013, Earth-Science Reviews 125. [3] Gribenski et al., 2021, Geology 49. [4] Monegato et al., 2017, Scientific Reports 7. [5] Kamleitner et al., 2023, Geomorphology 423. [6] Gianotti et al., 2008, Quaternary International 190. [7] Gianotti et al., 2015, Alpine and Mediterranean Quaternary 36.

Monsoon-induced floods have played a pivotal role in shaping the fortunes of Asian civilizations and communities over the millennia, and their far-reaching consequences persist to this day. This study delves into the floodplain east of Nan ancient city, a city during Lan Na period in northern Thailand dating back to the 13th century AD. Our primary objective was to unravel the source direction of a catastrophic flood event in 1818 AD, which ultimately led to the city's relocation. Our sedimentological analyses revealed a diverse range of deposition. An innovative provenance study using mid-infrared spectroscopy (MIRS), conducted for the first time in this region, indicated a significant contribution from eastern tributaries not from the Nan River. Only two of the nine sediment cores (WTR and HH2) presented evidence of Nan River sediment. Optically stimulated luminescence (OSL) dating revealed a striking pattern: modern floods dominated the shallow depths (ca. 0-1.10 m) of all cores, while deeper layers exhibited unexpectedly older ages, exceeding 11,000 years. This finding aligns with climate data from multiple proxies, suggesting that Nan ancient city, akin to neighboring e.g. Kingdom of Angkor, endured a dry period. Based on these comprehensive findings, we postulate that the 1818 AD flood catastrophe originated from the east. The deluge may have been triggered by rainfall during an extended dry spell, when the parched and compacted soil's permeability was severely diminished. This sudden surge of water swiftly transported the sediment, ultimately inundating and devastating the city. The insights gained from this study are a reminder of the profound impact of monsoon-related floods on human settlements in Asia. By understanding the conceptions between sedimentology, provenance, and climate, we can better comprehend the historical and ongoing challenges posed by these natural disasters and advance strategies for sustainable development in vulnerable regions.Keywords: flood sediment, monsoon, Southeast Asia, provenance analysis, OSL dating, Lan Na, Nan, Thailand

Reconstructing fluvial dynamics is a fundamental requirement for understating the interaction between past environmental changes and human adaptation. This study focuses on the central part of the floodplain of the Nan River in northern Thailand that likely played a role in the catastrophic flood of 1818 CE, which damaged the ancient of Nan city and forced its relocation. We investigated nine sediment cores from the floodplain and from the eastern tributaries of the Nan River, to identify the potential source of floods in the past. By combining the analyses of sedimentary characteristics and provenance, the study reveals that the eastern tributaries were the dominant sediment source for most areas, with the Nan River only influencing areas close to its channel. According to optically stimulated luminescence dating, the highest sediment accumulation occurred during the eleventh to thirteenth centuries CE, coinciding with agricultural expansion and deforestation, suggesting increased erosion in the catchment of the tributaries. These findings challenge the assumption that the main Nan River has been the primary contributor to flooding catastrophes in the region and highlights the potential crucial role of smaller tributaries in similar settings in other parts of the globe.

Dating glaciofluvial deposits is fundamental to reconstruct paleoglacial and paleoclimatic dynamics. However, partial bleaching and lack of suitable sediments make the application of luminescence dating to such deposits challenging. Single grain and cobble luminescence dating have been successfully used to tackle these problematics [e.g. 1, 2] and are combined in this study on glaciofluvial deposits from the northern Alpine foreland (Finsterhennen, Switzerland). Previous chronological investigations at the study site [3, 4, 5] suggest that the deposition of the glaciofluvial gravel lying directly underneath the till from the regional Last Glacial Maximum (LGM) occurred ca. 29 kyr ago, in response to the LGM glacial advance. By comparison with the existing age constraints, the present study aims (1) to test the combined application of single grain and cobble luminescence dating to Alpine glaciofluvial deposits and (2) to refine the two methodologies. Samples were collected from well sorted sand lenses and moderately sorted gravel at approximately the same depth within the pre-LGM glaciofluvial gravel. Single grain (SG) feldspar luminescence measurements were conducted on sand lens and gravel sandy matrix samples, while luminescence depth profiles were measured in individual crystalline cobbles. Preliminary results show good agreement between SG ages from the sand lens and previous chronological constraints. SG results from the sandy matrix of the gravel horizon are instead underestimated, potentially because of challenges in dosimetry estimation, due to the heterogeneous lithology and grain size of the gravel layer. Heterogeneous dosimetry appears less problematic for burial age estimation of cobbles, since the variation of dose rate with depth into the cobble is dominated by the dosimetry of the cobble itself. Preliminary cobble luminescence depth profiles show shallow bleaching fronts, with large variability between cores and surfaces of the same cobble. The limited luminescence signal resetting can be explained by the proximity of the glaciofluvial deposits to the advancing LGM ice front and by sediment transportation in turbid water. The intra cobble variability is instead potentially related to the cobbles’ heterogeneous lithology, implying differences in dosimetry and light attenuation within the clasts. References [1] Duller, 2006, Quaternary Geochronology 1. [2] Jenkins et al., 2018, Quaternary Science Review 192. [3] Schlüchter, 2004, Quaternary Sciences 2. [4] Preusser et al., 2007, Boreas 36. [5] Pfander et al., 2022, Swiss Journal of Geosciences 115.

Constraining the age of glaciofluvial deposits is essential for reconstructing paleoglacial dynamics. While luminescence dating is among the most commonly used approaches, incomplete resetting of the signal before sediment deposition makes its application to such deposits challenging. Single grain (SG) and cobble luminescence dating have been used to account for heterogeneous bleaching with different success, and are tested here in combination on glaciofluvial deposits from one site in the northern Alpine foreland. Previous chronological investigations indicate that deposition of the proglacial outwash occurred ca. 29 ka ago. SG feldspar results on sand lens and gravel sandy matrix samples underestimate the previous age estimates due to the occurrence of grains with low equivalent dose (De) values. When low De values are discarded, the estimated ages are in agreement with the independent constraints. Luminescence-depth profiles obtained from four cobbles show (1) no or only shallow bleaching, and (2) high variability between cores and surfaces of the same clast. Both aspects highlight the necessity of measuring numerous clasts and several cores in order to detect well-bleached clasts and profiles. The limited signal resetting can be explained by the proximity of the deposit to the glacial front. The intra-cobble variability is instead potentially related to heterogeneity in the cobbles’ lithology, implying differences in dosimetry, signal stability and light attenuation within the clasts. Electron microprobe analyses of feldspar in the clasts and comparison with the independent age constraints suggest that (1) the luminescence signal of the rock slices derive from both Na- and K-rich feldspars and (2) an average internal potassium content may be a good first order estimate for dose rate calculations. Overall, the present study highlights both the challenges and the potential of applying SG and cobble luminescence dating to partially bleached glaciofluvial deposits.

The site of Kimirek-Kum 1, located between two ancient branches of the lower course of the Zerafshan River, has been investigated by an international research team since 2022. Here we report on the archaeological fieldwork carried out in autumn 2023, which targeted potential habitation areas and major features previously recognized through subsurface detection methods, as well as the site's prominent circular 'enclosure' earthwork. We describe our field methods and the archaeological strata identified, providing the contextual foundation for ongoing material analyses and subsequent socio-cultural interpretations. All dated contexts fall between approximately 1300-1000 BCE, indicating a relatively concentrated period of site use. Although earlier-raised questions about metallurgical production at KK1 and direct cultural connections with steppe communities were not resolved during the autumn 2023 field season, notable results include the identification of occupation surfaces and associated refuse pits rich in burned animal bone, plant remains, ceramics, and construction material. Refuse-dumping was contained in stratigraphically-earlier clay-mining pits, ditch features, and water channels. Excavations also revealed the underlying sand and clay sediment structure of the site, and provided systematically-sampled material for reconstructing the archaeo-ecology and hydrological network around the site. Preliminary, in-field ceramic analyses suggest strong relationships to Early Iron Age cultural groups to the south, with some elements also indicating contemporary northern connections. This multi-directionality of material culture concords with results from pilot studies at Kimirek-Kum 1, placing it at a geographic and chronological crossroads in the late 2nd millennium BCE.

The drainage system of the Swiss Alps shifted from an eastward (Danubian) to a westward (Rhenian) direction during the Late Pliocene. Since then, the High Rhine Valley has acted as the major drainage path during both ice-free and glaciated periods in the past. The M & uuml;hlbach formation comprises the patchy remains of carbonate-free sediments that have been interpreted as an equivalent of Sundgau gravel. The Sundau gravel reflects remains of fluvial deposits related to the Late Pliocene drainage of the northern Swiss Alps through the Burgundian Gate towards the Bresse-Rh & ocirc;ne Graben. However, the limited data available characterising the M & uuml;hlbach formation have led to opposing interpretations regarding its origin and age. Presented here are new data on the distribution and physical appearance of the formation, together with luminescence dating of deposits from the type locality. Sedimentological and petrographic analyses imply that the various deposits assigned to the M & uuml;hlbach formation do not represent a genetically coherent formation. In addition, consistent results of quartz and feldspar luminescence dating place deposition of sediments at the type locality at ca. 55 ka. This dates their deposition to the end of a pronounced cold period during the Late Pleistocene that has been shown to be characterised by slope processes at other sites. Altogether, the data presented imply that the M & uuml;hlbach formation is not uniform but rather comprised of mainly reworked weathered residues from different time periods. Das Entw & auml;sserungssystem der Schweizer Alpen hat sich im sp & auml;ten Plioz & auml;n von einer & ouml;stlichen (Donau) zu einer westlichen (Rhein) Richtung verlagert. Seither hat das Hochrheintal sowohl in eisfreien als auch in vergletscherten Perioden als Hauptabflussweg fungiert. Die M & uuml;hlbach Formation besteht aus l & uuml;ckenhaften Resten karbonatfreier Sedimente, die als & Auml;quivalent zu den Sundgau Schottern interpretiert wurden. Letztere spiegeln & Uuml;berreste fluvialer Ablagerungen wider, die mit der sp & auml;tplioz & auml;nen Entw & auml;sserung der n & ouml;rdlichen Schweizer Alpen durch die Burgundische Pforte in Richtung des Bresse-Rh & ocirc;ne-Grabens zusammenh & auml;ngen. Die zur Charakterisierung der M & uuml;hlbach Formation durchgef & uuml;hrten Untersuchungen haben jedoch zu widerspr & uuml;chlichen Interpretationen hinsichtlich ihres Ursprungs und Alters gef & uuml;hrt. Hier werden neue Erkentnisse zur Verbreitung und zum Erscheinungsbild der Einheit sowie Lumineszenzdatierungen an der Typlokalit & auml;t vorgestellt. Sedimentologische und petrographische Analysen lassen darauf schlie ss en, dass die verschiedenen Ablagerungen, die der M & uuml;hlbach Formation zugeordnet werden, keine genetisch koh & auml;rente Formation darstellen. Dar & uuml;ber hinaus belegen & uuml;bereinstimmende Ergebnisse von Quarz- und Feldspat-Lumineszenzdatierungen, dass die Sedimente an der Typlokalit & auml;t vor ca. 55 ka abgelagert wurden. Dies datiert ihre Ablagerung auf das Ende einer ausgepr & auml;gten Kaltzeit w & auml;hrend des Sp & auml;tpleistoz & auml;ns, die nachweislich an anderen Standorten durch Hangprozesse gekennzeichnet war. Insgesamt deuten die vorgelegten Daten darauf hin, dass die M & uuml;hlbach Formation nicht einheitlich ist, sondern haupts & auml;chlich aus umgelagerten Verwitterungsresten verschiedener Zeitabschnitten besteht.

The structure and age of remains of two ancient walls located in the city of Nan, a former part of the Lanna Kingdom in modern northern Thailand, were investigated. The remains differ in appearance with a well-preserved brick wall present at Mahawong Road (MHW), while an earthwork with a brick reinforcement core is found at Phaya Wat Temple (PWT). We employed an electrical resistivity tomography (ERT) survey and optically stimulated luminescence dating (OSL) to determine the buried structure of the earthwork at the PWT site and the production age of bricks from both locations. The ERT results reveal lateral heterogeneous resistivity domains cross-cutting the wall, which presumably relates to the construction of a dam. According to OSL dating, the PWT wall was likely built during the time of the war with Burma that ultimately resulted in a foreign occupation of Nan in the sixteenth century. This structure played a role in both flood mitigation and military defence of the city. The structure at MHW represents a city wall that was built at the end of the nineteenth century after Nan was relocated to its present position and rather reflects representative and social needs.

A complex picture of the Pleistocene glaciation history of northern Switzerland has been identified over the last three decades. To gain further insights into the long-term landscape evolution, numerical dating is required. In the absence of alternative dating techniques, luminescence dating is the key method for establishing chronological constraints of past glaciations. However, this is presented with complex challenges, especially in regard to the resetting of the luminescence signal prior to deposition, the components contributing to the signal as well as the signal intensity and stability. In this study, the luminescence properties of glacially sourced deposits from northern Switzerland are assessed using single aliquot (SA) and single grain (SG) measurements of feldspar (F) and quartz (Q). While no obvious connection between bleaching and distal or proximal deposition in relation to the proposed ice margin is observed, most samples seem to reveal a partially bleached signature in F SG De measurements. This appears to be masked in the respective F SA measurements even though only few grains emit luminescence signals. In addition, comparisons between fading corrected infrared stimulated luminescence (IR) and post-infrared infrared stimulated luminescence (pIR) De values appear to be unreliable indicators of bleaching, even though these signals bleach at different rates. Hence, it is recommended to conduct both IR and pIR investigations in combination with Q measurements on a SG level. The dating potential of the investigated deposits remains rather limited, yet, in the sedimentologic context the presented results reveal that several glacial advances occurred prior to the Last Interglacial in the study area.

Glacially overdeepened basins are a common landform of subglacial erosion. However, the controlling erosional-depositional processes and their age remain poorly understood on a global scale. Terminal overdeepenings near the former glacier margins are critical for the understanding of subglacial processes and their development over time. This study examines the geomorphology and sedimentology of buried terminal overdeepenings eroded below the Rhein Glacier and adjacent lobes in the distal northern foreland of the European Alps. The evolution of erosion and infilling in the overdeepened troughs over time is investigated using high-quality drill cores ( 1463 m of core in total) that were logged for lithofacies, petrophysical, geotechnical and compositional properties. The drill data is integrated with 2D-reflection seismics ( 41 km in total) and supplementary subsurface data. This extensive dataset reveals that the studied overdeepened basins include twelve typical facies associations (partially emplaced in characteristic sequences) and characteristic architectural elements. These categories serve as effective tools to reduce the high facies variability and facilitate easier comparison and correlation of the valley fill. Our analysis shows that the formation of terminal overdeepenings on soft sedimentary bedrock (Molasse) is the result of a combination of erosional processes. Subglacial water erosion and evacuation are the dominant processes and active during periods of glacier-bed decoupling and flushing. Direct subglacial erosion occurs during glacier-bed coupling and is documented by bedrock glacitectonites. The valley fill architecture shows that the studied overdeepenings typically undergo a multiphase evolution, with several phases of overdeepening erosion, deposition and partial re-erosion (or re-activation). The combined dataset (including geochronological data) suggests that the overdeepenings were eroded during many, if not all, extensive glaciations during the Middle-Late Pleistocene that reached the distal foreland. These are findings relevant for the large number of overdeepenings known from the Northern Alpine foreland and overdeepened features worldwide. They corroborate the importance of overdeepenings as archives for the paleoenvironmental change and landscape evolution during the Quaternary.

Prograded barriers are coastal landforms with a worldwide distribution that provide a paleoenvironmental record within a sequence of successive ridges and intervening swales. Most barriers with variable terrestrial morphologies, also known as complex barriers, have been poorly studied. At the main entrance of Western Port, a bay in southeastern Australia, a morphologically complex barrier was formed as a function of its somewhat sheltered position and orientation in relation to sporadic swells and tidal circulation. LiDAR-derived topography shows highly truncated and asymmetrical ridges both across and along the Somers-Sandy Point barrier plain. These uncommon morphologies are associated with an intricate hydrodynamic circulation subject to sporadic storms approaching at a sharp angle to the shoreline that eliminate a significant part of the sedimentary record but also redistribute vast quantities of sand to the downdrift shoreline, and a large and variable sandy bank that undergoes intense sediment movement. Optically stimulated luminescence (OSL) dating within a limited area on the western side revealed an age of similar to 2600 years for the innermost dated ridge, located about halfway across the plain. Significant erosion of the ridges' record occurred on the western side of the barrier between 2600 and 700 years ago and between 600 and 240 years ago, whereas undated ridges on the eastern side were preserved. This creates an opportunity for future research on past erosional events that would be of great value for coastal management and adaptation. Textural and elemental (XRF) sediment characteristics suggest that the type of material provided for barrier accretion remained the same throughout the late Holocene. Given the sustained growth of the barrier and other sandy parts of the bay, a net supply of marine sand from Bass Strait must have occurred. The proposed evolutionary model contributes to the understanding of the sediment budget for the bay as a whole.

Multi-archive studies of climate events and archive-specific response times require synchronous time scales. Aligning common variations in the cosmogenic radionuclide production rate via curve fitting methods provides a tool for the continuous synchronization of natural environmental archives down to decadal precision. Based on this approach, we synchronize 10 Be records from Western Gotland Basin (WGB, Baltic Sea) and Lake Kälksjön (KKJ, central Sweden) sediments to the 14 C production time series from the IntCal20 calibration curve during the Mid-Holocene period ~6400 to 5200 a BP. Before the synchronization, we assess and reduce non-production variability in the 10 Be records by using 10 Be/ 9 Be ratios and removing common variability with the TOC record from KKJ sediments based on regression analysis. The synchronizations to the IntCal20 14 C production time scale suggest decadal to multi-decadal refinements of the WGB and KKJ chronologies. These refinements reduce the previously centennial chronological uncertainties of both archives to about ± 20 (WGB) and ±40 (KKJ) years. Combining proxy time series from the synchronized archives enables us to interpret a period of ventilation in the deep central Baltic Sea basins from ~6250 to 6000 a BP as possibly caused by inter-annual cooling reducing vertical water temperature gradients allowing deep water formation during exceptionally cold winters.

High-resolution sedimentological and geochronological investigations of paleochannel systems in the Ried Central d'Alsace (northeastern France) allow for the reconstruction of the late glacial and Holocene fluvial evolution of this section of the Upper Rhine alluvial plain. During the Oldest Dryas, the landscape featured a dominant braided Rhine system and, to a lesser extent, a braided Fecht system. The shift to the B & oslash;lling-Aller & oslash;d saw a narrowing of the Rhine's active channel belt, the development of a complex channel pattern, and the genesis of the Ill River. The river channel patterns remained unchanged during the Younger Dryas. In the Early Holocene, the Rhine's active belt narrowed further, and the Rhine and Ill Rivers developed braided-anastomosing and anastomosing channel patterns, respectively. Throughout the Holocene, both rivers maintained their channel patterns while migrating east and west across the alluvial plain, respectively. In the late glacial, fluvial dynamics in this section of the Upper Rhine plain were primarily influenced by climate-related environmental and hydrogeomorphological changes. Conversely, during the Holocene, the evolution of the fluvial hydrosystems was driven by a complex interaction of climatic and non-climatic factors, including human activity at the catchment scale, alluvial plain architecture, and local neotectonics.

The eastern Rhine Graben Boundary Fault (eastern RGBF) forms the eastern margin of the Upper Rhine Graben (URG), the most seismically active area in the plate interiors of Europe. Despite seismic activity posing a significant threat to the densely populated URG and critical facilities therein, only a few studies have documented the paleoearthquake history and associated seismic hazard, focusing mainly on the western margin. We present the results of the first paleoseismological trenching ever conducted on the eastern RGBF. Following highresolution near-surface geophysical studies, we excavated six trenches near EttlingenOberweier (south of Karlsruhe, Germany) on one of its secondary fault strands. The nearlyvertical fault is transtensional left-lateral and splits into several NNW-SSE en échelon branches, forming a negative flower structure. Stratigraphic and structural relationships along with radiocarbon and Optically Stimulated Luminescence dating reveal a minimum of three surfacerupturing paleoearthquakes with a moment magnitude of potentially 6.5 ± 0.5, occurring from old to young, >56 ka (EX), between 55 ka and 21 ka (EY), and between 17 ka and 1 ka (EZ). The events are poorly constrained in age due to unconformities, which may hide other paleoearthquakes. Based on the cumulative vertical separation (1.2 ± 0.3 m), we calculate a vertical slip rate of 0.02 ± 0.005 mm/yr. From a horizontally offset alluvial channel depicted in electric resistivity tomography (ERT) profiles and scarp-parallel trenches, we infer a cumulative left-lateral slip of 5.9 ± 0.7 m and derive a horizontal slip rate of 0.1 ± 0.01 mm/yr. The average net slip rate value is 0.1 ± 0.02 mm/yr for the past 59.5 ± 2.7 ka. Our findings highlight the seismic potential of the eastern RGBF, providing new evidence of the Late Pleistocene and Holocene tectonic activity of its central section.

Well-known for their geological and natural singularity, the Dead Sea brines evolved from a marine ingression of the Mediterranean during the Pliocene. Dead Sea brines are currently almost ten times more concentrated than seawater and have a unique chemical composition with high boron isotope values (δ11Bbrine = ∼57‰). However, little is known on how these values were attained and their underlaying driving processes. Here we use boron isotopes (δ11B) combined with B/Ca and B/Li of lacustrine authigenic aragonites from the deep basin drill-core ICDP 5017-1, and Ein Gedi and Masada profiles to reconstruct past brine conditions. Comparing reconstructed δ11Bbrine from two key periods of contrasting hydro-climatic regimes we find that the brines of the late Holocene Dead Sea were enriched in 11B (δ11Bbrine = ∼60‰) relative to its glacial precursor Lake Lisan (∼57‰). With the aid of boron cycle modelling, we quantify the main boron fluxes in the basin. We show that the post-glacial δ11Bbrine enrichment is best explained by overall reduction of freshwater inflow to the lake and coeval increase in 10B sink through boron co-precipitation in evaporitic deposits and boron loss in atmospheric water vapour, consistent with the onset of warmer and drier climate in the Eastern Mediterranean during the Holocene. On geological time scales, adsorption of 10B on clastic sediments has acted as an important 10B sink and can explain the evolution of the high δ11Bbrine values.