The interplay between weathering, denudation, deposition, and preservation makes fluvial source-to-sink signal propagation research inherently multidisciplinary, particularly across sedimentology and geomorphology. For example, lithological properties and weathering rates determine erodibility and system response times, while basin configuration impacts downstream channel dynamics, sediment delivery, and the character of sedimentary variability. Advancing understanding of these interactions is essential to constrain system sensitivity across timescales, and the preservation potential of different signal types.
We invite contributions from projects that advance knowledge of Earth surface dynamics in response to tectonic, climatic, environmental, and weathering controls, with a particular emphasis on integrative approaches that link geomorphic processes, sedimentary archives, and stratigraphic preservation.
Orals: Fri, 8 May, 16:15–18:00 | Room G1
The Sadler effect is defined as a systematic decrease in estimated rates with increasing measurement interval and is widely observed in stratigraphic and geomorphic systems. In natural systems, statistics themselves do not cause phenomena; rather, physical processes operate across landscapes, generating responses that can be characterized by statistics. However, it is statistical phenomena (a heavy-tailed distribution via random walks or stochastic memory formulations) that are frequently invoked to explain the Sadler effect, which provides no insight into the physical processes that generate a heavy-tailed distribution. Here, we explore how the Sadler effect might arise in a system where thresholds must be exceeded to produce an erosive event. We argue that apparent heavy-tailed hiatus distributions can emerge naturally when considering physically reasonable geomorphic dynamics. Using a simple stream power-based stochastic threshold-incision framework, we show that systems governed by static thresholds and stationary forcing produce exponential hiatus distributions. In such circumstances, a Sadler-like effect is observed, but only over a finite time span set by the characteristic hiatus return time, after which rates remain constant. In contrast, when thresholds evolve through time—either via event-driven perturbations with recovery (system memory) or through temporal changes in the forcing distribution (e.g., climate variability)—the system samples a sequence of exponential hiatus distributions with distinct characteristic timescales. The superposition of these exponential hiatus distributions produces an apparent heavy tail and sustains Sadler-like scaling across multiple orders of magnitude in time. This framework provides a physically interpretable alternative to purely statistical explanations of the Sadler effect and highlights the central role of variable threshold magnitude, recovery timescales, and climate variability in controlling signal preservation in geomorphic systems. Importantly, these concepts likely extend to interpreting the Sadler effect in the stratigraphic record. The results suggest that apparent long-memory behavior in erosion and deposition records may reflect evolving thresholds and forcing regimes, rather than intrinsic heavy-tailed dynamics.
How to cite: Gallen, S., Rugenstein, J., Axness, A., Drobnich, K., Khatiwada, A., Kondracki, P., Perez, A. M., Richardson, O., and Xu, C.: Thresholds, Memory, and a Physical Mechanism for the Sadler Effect in Geomorphic Systems, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4544, https://doi.org/10.5194/egusphere-egu26-4544, 2026.
Climate forcing influences the frequency and magnitudes of debris-laden flows (including hyperconcentrated flows and debris flows), which are controlled by intense local precipitation events. Reconstructing debris flow activity is challenging due to incomplete archives, a lack of historical evidence, and unrepresentative precipitation data of local rainfall intensity. To reconstruct past activity and infer future precipitation thresholds, we need robust archives that include a wide range of temporal and spatial scales. Plansee (Tyrol, Austria) is a relatively pristine and virtually closed source to sink system. Sediment is transferred from 54 transport-limited Hauptdolomit catchments to the lake-adjacent fans. Debris-laden flows regularly enter the lake as underflows, creating turbidites in the basin. Lacustrine sediment cores taken from the fan delta towards the depocenter offer a 4000-year archive with 138 debris-flow-induced turbidites. The photogrammetric reconstruction of historical aerial imagery since 1952 enables the quantification of elevation changes in the active debris flow channel, allowing for the estimation of the sediment budget at each fan. In this contribution, we compare the in-lake deposition rates from the sediment cores with the terrestrial erosion, deposition, and net volumes at each surrounding fan, to conclude that both calculations match.
The frequency of debris-laden flows has increased significantly since 1920, with a most recent peak after the 1980s observed in the terrestrial record. The terrestrial inventory reveals varying activity over the decades on all fans, providing a better understanding of the mechanisms and controlling factors of sediment propagation in pre-alpine catchments. This contribution presents for the first time the integration of lacustrine and terrestrial records to reconstruct historical debris flow activity and outline trends in frequencies and magnitudes.
This research is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation – Project number 558963977) and the Austrian Science Fund (FWF, grant https://doi.org/10.55776/PIN7180424)
How to cite: Kiefer, C., Barbosa, N., and Krautblatter, M. and the ALPHA Lakes Team: Increasing debris-laden flow volumes at Plansee (AT): Comparing the lacustrine sedimentary archive with the terrestrial sediment budget from historical aerial imagery, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14675, https://doi.org/10.5194/egusphere-egu26-14675, 2026.
In the study of rift basins, the source-to-sink system theory offers a fundamental framework for deciphering sedimentary filling processes and sandbody distribution patterns. This system is strongly influenced by the basin’s structural architecture, paleogeomorphic evolution, and base-level cycles. The spatiotemporal dynamic coupling of three key elements—sediment supply, transport pathways, and depositional convergence—directly governs sandbody formation and distribution, providing important theoretical insights for hydrocarbon reservoir prediction. This study focuses on sediment transport processes through sandbody pathways in complex rift basins and evaluates their differential controls on sandbody convergence within braided-river delta and lacustrine depositional systems under varying base-level cycles. Data from the Shenxian Sag in the Bohai Bay Basin, including extensive core samples, well logs, 3D seismic data, and laboratory analyses, support this investigation.Based on these data, the paleogeomorphology of key sequences was systematically reconstructed. Five valley types, three major slope-break zones, and four categories of accommodation zones were identified, with their controls on sedimentary pathways analyzed in detail. Significant differences were observed between the steep-slope and gentle-slope belts in terms of sediment supply, sandbody scale, and distribution patterns. Under the guidance of the source-to-sink theory, a spatiotemporal sand-control mechanism was established, with base-level cycles acting as the primary regulatory factor and paleogeomorphic elements serving as spatial carriers. This mechanism integrates three core components: sediment supply, transport pathways, and depositional convergence.The study further systematically elucidates four coupling modes and their corresponding sedimentary effects across different tectonic stages and structural units. Sediment supply provides the material basis for reservoir sandbody development, with its volume and intensity modulated by base-level fluctuations. The transport system is mainly constrained by paleogeomorphic features such as paleo-valleys, slope breaks, and accommodation zones. Among these, valleys demonstrate high sand-transport efficiency during base-level lowstands, which diminishes considerably during rising phases. Slope breaks in the northern gentle-slope belt are jointly controlled by base-level cycles and tectonic activity, whereas composite slope breaks in the southern steep-slope belt play a redistributive role in sandbody dispersion. The classification and sand-controlling functions of accommodation zones vary with the characteristics and configuration of syndepositional faults. The convergence system is regulated by cyclic changes in accommodation space driven by base-level movements. During base-level rise, lake-level expansion and increased accommodation space promote the development of retrogradational sequences, whereas base-level fall reduces accommodation space and favors progradational sequences. The transport and convergence systems are spatially linked and interact dynamically, with their functional relationships capable of shifting under the influence of base-level cycles.These findings provide effective guidance for predicting favorable sedimentary facies belts and sandbody distributions in the study area, leading to the identification of four prospective exploration targets. Subsequent drilling results have confirmed their potential. The research outcomes offer a new theoretical foundation and practical model for hydrocarbon exploration and sandbody prediction in analogous complex rift basins.
Keywords: source-to-sink system, sand-controlling mechanism, base-level cycle, palaeogeomorphology, Shenxian Depression, Shahejie Formation
How to cite: Li, X. S.: Sediment Control Mechanisms Under the Regulation of Base-Level Cycles in Complex Rift Basins: Spatiotemporal Coupling of "Source-to-Sink" Systems —A Case Study of the Middle - Deep Zone in the Shenxian Sag, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8498, https://doi.org/10.5194/egusphere-egu26-8498, 2026.
During the early Miocene, the Ebro Basin evolved as an endorheic depression bounded by the Pyrenees, the Iberian Range, and the Catalan Coastal Ranges. In its central sector, extensive and laterally continuous lacustrine systems developed under variable climatic conditions, including warm-humid phases such as the Miocene Climatic Optimum. The La Muela section is composed of lacustrine sediments from the southern margin of the Ebro Basin’s central lake. The La Muela section documents significant geochemical changes in the lake system, beginning with mudflat environments, followed by evaporitic conditions, and subsequently a return to carbonate-dominated deposition. The well-exposed outcrops and the possibility to correlate this record with other sectors of the basin make it an ideal site for reconstructing environmental variations of the complete system and understanding its geochemical changes. Achieving an accurate correlation between the different sedimentary records requires very fine time correlation lines.
To address this correlation problem, we present a local magnetostratigraphy for the La Muela section based on the analysis of 155 samples distributed over a thickness of 190 meters. A correlation with the Global Geomagnetic Polarity Timescale allows us to propose a new chronology that includes the early to middle Miocene transition. By means of basin-wide magnetostratigraphic correlations, we determine local sedimentation rates across the different sectors. Finally, we discuss the timing and relevance of the major compositional changes in the lacustrine settings, which, constrained by isotopic records, reveal the environmental evolution of the basin.
How to cite: Arriolabengoa, P., Valero, L., Arenas, C., Beamud, E., Maestre, E., and Garcés, M.: Magnetostratigraphy of the middle Miocene La Muela section: a chronostratigraphy across the central Ebro basin lacustrine units, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12650, https://doi.org/10.5194/egusphere-egu26-12650, 2026.
Deciphering how Earth’s surface has responded to the extreme climates of the past is vital for understanding the impacts of global warming on our planet in the present and future, including flood and drought risk worldwide. Rivers are the most significant conduits of water, sediment and nutrients across Earth’s continents, and the patterns of river water and sediment transport through time, or river intermittency, are thought to be highly sensitive to geomorphic bounding conditions such as climate and tectonics. Determining the intermittency of rivers in ancient hothouse climates provides a unique lens through which to investigate this question. However, this requires strong constraints on sediment and water discharges and volumetrics from source to sink, which are rare due to the challenges of estimating bankfull and average water and sediment fluxes at continental scale. We reconstruct the evolving source-to-sink dynamics of the lower Eocene Montllobat (52.0 – 50.5 Ma) and Castissent (50.5 – 49.7 Ma) Formations, in the dynamic tectono-climatic setting of Southern Pyrenees during the Eocene Hothouse. By estimating fluvial morphodynamics and discharges in the Tremp and Ager Basins, in addition to depositional fluxes in the underfilled Ainsa and Jaca Basins, we estimate water and sediment intermittency in these systems for the first time. Sediment intermittency factors (Is) in the Montllobat Formation average 0.009-0.029, implying annual sediment loads could have been completed with as little as 1 week of transport at bankfull capacity. The overlying Castissent Formation, characterized by enhanced braiding and sediment discharge, has higher Is values of 0.012-0.036. Water intermittency factors (Iw), on the other hand, decreased from 0.25 in the Montllobat interval to 0.15 in the Castissent interval, implying perennial rivers almost halved their activity at c. 50.5 Ma. This suggests river discharge rapidly became more extreme and infrequent, whilst sediment became transported more efficiently. Coeval to a pulse of uplift in the Pyrenean hinterland, we reveal the deposits of the Montllobat and Castissent rivers record strong competing climatic and tectonic signals which drove over 20 km of fluvial progradation. Further, in comparison to modern systems, the Eocene rivers of the Pyrenean foreland have higher sediment intermittency factors than anticipated, transporting sediment more efficiently than similar rivers today. This suggests hothouse climates can cause reduced sediment export timescales, with important implications for source-to-sink dynamics in today’s evolving climate.
How to cite: McLeod, J., Whittaker, A., Hampson, G., Bell, R., Prieur, M., Fuller-Field, O., Valero, L., and Yan, X.: Hothouse hydrology: new insights from water and sediment transport patterns in the Eocene Pyrenees , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11505, https://doi.org/10.5194/egusphere-egu26-11505, 2026.
To understand sediment transport from the Himalayan source regions to the foreland basin over multi-millennial timescales, it is essential to quantify both hillslope erosion rates and sediment storage times within the mountain belt. In this study, we estimate paleo-erosion rates of the Himalaya using paired cosmogenic radionuclide (10Be and 26Al) concentrations from 62 alluvial sediment samples collected from drill cores and riverbeds across four major Himalayan-River basins. By correcting the nuclide concentrations for sediment storage time, we show that neglecting storage-effects can lead to a systematic overestimation of erosion rates.
Paleo-erosion rates of Himalayan hillslopes derived from all four river basins show a consistent, near-linear increase through time from the late-Pliocene to the present. This trend is observed from the western Himalaya (modern riverbed samples from north of the Main Frontal Thrust and the paleo-Sutlej) through the central Himalaya (paleo-Yamuna and Ganges) to the central-eastern Himalaya (Kosi). In the Sutlej basin, erosion rates increase from ~0.07 mm/y at 2.95 Ma to 1.79 mm/y at present. The paleo-Yamuna records a rise from ~0.2 mm/y at 3.3 Ma to 1.9 mm/y at 0.6 Ma. Similarly, the Ganges basin shows an increase from ~0.24 mm/y at 3.7 Ma to 2.04 mm/y at 0.9 Ma, while the Kosi basin exhibits the strongest acceleration, from ~0.12 mm/y at 4.42 Ma to 4.37 mm/y in modern samples.
We attribute the temporally increasing trend of the paleo-erosion rates on glacial erosion. Expansion of glaciers in the high altitudes of the Himalayan region occurred after ~2.7 Ma, due to the growth of the northern hemispheric icesheet. Additionally, the increased seasonality of the south-east Asian monsoon and initiation of the Pleistocene glacial-interglacial cycle possibly have led to higher glaciation, which in turn resulted in higher erosion rate in the Himalaya after ~2 Ma.
How to cite: Bhattacharjee, S., Bookhagen, B., and Sinha, R.: Plio-Pleistocene and modern erosion rates in the Himalaya from paired cosmogenic radionuclides , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5053, https://doi.org/10.5194/egusphere-egu26-5053, 2026.
The formation of dune and paleodune sequences along the Pacific coast of Central Chile (30-35° S) remains poorly understood. The Andean glaciated landscape seems to exert a major influence on sediment supply, although the coupling between glacier fluctuations and dune build up in the Pacific coast remains speculative. Drainage basins, modulated by climatic and tectonic forcings, produce and transfer sediment from source areas to continental and marine sinks. However, transport pathways are complex as sediment may be temporarily stored and mixed along fluvial systems, decoupling source signals from downstream sinks by delaying or partially erasing them. Sediment residence time integrates both transport duration and temporary storage within a basin. Constraining it is essential to evaluate whether climatic signals such as glacier fluctuations can be faithfully transferred to the Pacific coast and recorded in dune deposits, allowing a better understanding on the formation of these systems. Here, we estimate sediment residence times in the Rapel Basin using paired in situ cosmogenic 14C and 10Be measured in modern fluvial and dune sands. As 14C has a much shorter half-life than 10Be, this pair is particularly sensitive to periods of sediment storage and can be used to quantify the time sediments spend in transient reservoirs along their transport pathways. Therefore, we adopt a source-to-sink sampling strategy, collecting sediments from distinct geomorphic domains along the basin, from the Andean headwaters to the coastal dune systems. Our results indicate that all samples experienced some degree of storage during transport, with minimum residence times of ~2.5 kyr in the Andean glacial domain and maximum values of ~14 kyr in dunes at the Pacific coast. At the source zone, residence times ranging from ~2.5 to ~7.5 kyr suggest that sediments record a millennial scale residence signal prior to entering the fluvial network, likely due to storage in glacial environments and on hillslopes. Once sediments enter the channel network, transport through the medium and lower basin appears to be largely efficient, with little additional storage until reaching the Pacific coast. From the river mouth to the dune systems, sediments record up to ~4 kyr of additional residence time relative to the Andean source signal. Such addition indicates a millennial scale lag time in source signal transmission towards the dunes. Our dataset suggests that sediment residence times within the Rapel Basin (Central Chile) are primarily controlled by sediment generation rather than by complex fluvial transport histories itself. Only at the river mouth, significant additional residence times are added to the signal as sediment is transferred towards the dunes, as part of the long-shore littoral drift. These results demonstrate that even with a millennial timescale lag at the coast, the dune systems remain sensitive archives that record the primary Andean signal.
How to cite: Dal Pai, M., García, J. L., Villaseñor, T., Castillo, P., Schildgen, T., and Lifton, N.: From Source to Sink: linking the Andean source signal to coastal eolian sand-dunes using cosmogenic 10Be/14C residence times in Central Chile, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20918, https://doi.org/10.5194/egusphere-egu26-20918, 2026.
The Atacama Desert is considered the driest and oldest non-polar desert on Earth featuring numerous indications for an Early Miocene onset of its hyperaridity. Despite vast evidence for long-term hyperaridity dominating the landscape evolution of the desert’s core, younger Quaternary fluvial modification has been deduced from various archives across the Atacama Desert. Located within the N-S-extending Coastal Cordillera, a significant portion (>10%) of the western Atacama Desert’s surface geology is recognized as Quaternary deposits predominantly related to past alluvial fan activity. However, only few and patchy stratigraphic and geochronological constraints exist on the formation of those depositional landforms. We therefore systematically studied the alluvial fans across the Coastal Cordillera at ~21°S by combining DEM-based morphometric assessment, establishing morphochronological frameworks by in situ terrestrial cosmogenic nuclide dating, and stratigraphic analyses by geophysical surveys and sedimentological-pedological analyses of a soil pit. Significant fan-catchment morphometric relationships indicate intact source-to-sink connectivity and signal propagation. The youngest and last abandoned surface generations of four multi-stage alluvial fans were dated by 10Be exposure dating, complemented by reappraisal of 10Be data from an alluvial fan system published by Baker et al. (2013). Site-specific timing of terminal fan aggradation dates to the late Middle Pleistocene and beginning of the Early–Middle Pleistocene Transition (EMPT) for the youngest and penultimate stages, respectively. Interpreted in the form of a regional geochronological compilation, fluvial-alluvial activity shows additional peaks during the Last Interglacial Complex. Late and Middle Pleistocene palaeoclimatic signals are largely in agreement with other Quaternary sediment records from the central Atacama Desert. While alluvial fan evolution within the Coastal Cordillera is rooted in the tectonic evolution of the basin settings, integrated results strongly indicate a close coupling between Quaternary fluvial activity and palaeoclimatic variability. Our study provides first evidence for a major fluvial modification during the EMPT. Moreover, we can infer a dominant effect of the maximum inland extent of advective fog on preventing long-term landscape stabilisation and conservation.
Reference
Baker, A., Allmendinger, R.W., Owen, L.A., Rech, J.A. (2013). Permanent deformation caused by subduction earthquakes in northern Chile. Nature Geoscience 6, 492–496. https://doi.org/10.1038/ngeo1789
How to cite: Walk, J., Mohren, J., Quezada, A., Blanco Arrué, B., Roas, J., Schwarze, P., Krieger, J., Wild, A., Binnie, A., Binnie, S., Ritter-Prinz, B., Yogeshwar, P., Brill, D., Brückner, H., and Frank, L.: Quaternary alluvial fan evolution in the western Atacama Desert, North Chile, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12041, https://doi.org/10.5194/egusphere-egu26-12041, 2026.
Traditional tools for coastal-fluvial terrace correlation (e.g. height above sea level, terrace morphology, sedimentary facies) are useful but often insufficient to resolve the complex interplay of tectonic, glacio-eustatic sea level and climatic changes that control the formation of terraces. Absolute age constraints are therefore essential to quantify the external signals and landscape changes, and to link with regional- to global-scale palaeoenvironmental changes. Here, we present a multidisciplinary study of shallow-marine, to littoral, to fluvial sediments of the three lowermost terraces (<5 m, 8-12 m, 15-35 m) that are exposed along the coastal plain of the Neogene Polis graben in NW Cyprus. We utilise new quartz luminescence dating of littoral to fluvial fine-grained sands, and existing uranium-series dating of solitary corals, together with sedimentological and geomorphological analysis of the terrace deposits. Our main aim is to establish a chronological framework for the terrace development and to aid regional mapping of the terrace surfaces. Previous terrace correlations (coastal to inland) suggest that the three lower shallow-marine terraces correspond to marine isotopic stages (MIS) 7 (c. 185-219 ka), 5e (c. 116-141 ka) and younger. Our new luminescence dating of inland littoral to fluvial terrace deposits reveals substantially younger ages of c. 45-63 ka, corresponding to overall regression during MIS 4-3. Luminescence dating and profiling results establish a detection limit of c. 1.22 ka (MIS 1), representing the youngest resolvable coastal sediment age. Assuming these dated deposits accumulated near sea level, uplift rates of 1.35-1.65 mm/year are implied. This contrasts with uplift rates (0.2-0.5 mm/year), as calculated from previous uranium-series dating of solitary corals from marine terraces correlated with MIS 5-7, elsewhere in Cyprus. However, there is no reason for greatly increased uplift rates after c. 45-63 ka, particularly within the active Polis graben, in which subsidence is indicated by localised modern marine erosion of older non-marine deposits (e.g. terra rossa palaeosols). Instead, we hypothesise that the luminescence-dated littoral-fluvial sediments accumulated up to c. 1 km inland, either in a contemporaneous setting and/or involving reworking of older shallow-marine terrace deposits, and that this was followed by downslope fluvial reworking of mixed siliciclastic-bioclastic sediments. Shifts from cooler, semi-arid conditions to warmer, wetter conditions during MIS 4-3 regressions repeatedly enhanced continental runoff. Alluvial fans prograded seawards episodically, followed by partial marine erosion. Later stage eustatic sea-level changes (MIS 3-2) culminated in erosional downcutting to near present sea level. Coastal sands near present-day sea level accumulated during MIS 1 transgressions, culminating in the development of the modern storm-influenced rocky shoreface, including beachrock. To conclude, uplifted coastal marine–fluvial terraces were partially eroded and covered by mixed siliciclastic-bioclastic sediments, reworked from upslope, that yielded relatively young depositional ages. Such deposits should not be misinterpreted as shoreface deposits, which would lead to calculation of anomalously high uplift rates.
How to cite: Antoniou, C., Robertson, A., Kinnaird, T., and Srivastava, A.: Upper Pleistocene–Recent Coastal-Fluvial Terrace Deposits of the Polis Graben, NW Cyprus: Implications of New Luminescence Dating, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18123, https://doi.org/10.5194/egusphere-egu26-18123, 2026.
The local geomorphological setting of sink areas strongly influences the distribution, preservation and thickness of loess sequences. For example, high accumulation and preservation occurs in depressions or on the leeward slope of topographic barriers. The sediment availability depends on the distance to source areas, such as large river systems, dry shelves, and glacio-fluvial outwash plains at the margins of ice sheets and glaciers. Vegetation density in these areas also governs the amount of dust that can be deflated, as vegetation increases surface roughness and acts as a dust trap, fixing the sediment. The most well-developed loess sequences were formed where alluvial terraces intersect slopes in stepped terrace systems, as seen in the valleys of the Dnieper, Danube and Rhine rivers in Europe, among others1. Deflation of dust from various source areas, followed by deposition and reworking in different geomorphological settings results in a mixture of the accumulated material, which complicates the reconstruction of the original source areas.
Under favorable preservation conditions, such as in the Dehner Dry-Maar, heavy mineral analysis of lacustrine sediments has enabled the distinction of phases of dust inputs from local, regional and remote source areas2. During phases with denser vegetation and forest cover, local sources are important; however, during the last 40 k years, when vegetation was mostly less dense, distant dust sources such as the dry North Sea shelves and reworked loess deposits played a major role. Loess deposits exhibit different facies due to processes associated with the geomorphological setting which controls reworking by different processes such as periglacial and fluvial processes. The geomorphologic position of loess sequences is one of the key-factors controlling its role as silt sink – in both a temporal and spatial context..
1 Lehmkuhl, F. et al. Loess landscapes of Europe – Mapping, geomorphology, and zonal differentiation. Earth-Science Reviews 215, 103496 (2021).
2 Römer, W., Lehmkuhl, F. & Sirocko, F. Late Pleistocene aeolian dust provenances and wind direction changes reconstructed by heavy mineral analysis of the sediments of the Dehner dry maar (Eifel, Germany). Global and Planetary Change 147, 25–39 (2016).
How to cite: Lehmkuhl, F., Römer, W., Zeeden, C., and Sirocko, F.: Sources and sinks for dust in Europe: Examples for climatic and geomorphological induced changes in the European loess and its deposition , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10334, https://doi.org/10.5194/egusphere-egu26-10334, 2026.
The Gulf of Corinth (GoC), central Greece is a relatively young rift (~2 Myr) with high extension rates (10-15 mm/yr) making it an ideal location to study the effects of tectonics and climate on sediment dynamics during early-stage rifting. The GoC’s stratigraphy is divided into two main units separated by a basin-wide unconformity that occurred at ~790 ka. Below the unconformity is a low-amplitude, less-coherent seismic package. Above the unconformity are alternating high-amplitude and low-amplitude seismic packages which correspond respectively to the GoC’s climate-driven connection to and separation from the global ocean.
Using the GoC’s dense network of offshore 2D seismic data tied to IODP Expedition 381 cores, we quantify the sedimentary budget accumulated in the GoC at high resolution (<50 kyr timescale) where seismic resolution allows (present - 330 ka), and lower resolution (<160 kyr) before (330-790 ka). We extract clastic solid volumes from isopachs between 3D seismic surfaces generated from interpretation of multiple 2D surveys. We incorporate uncertainties resulting from the time to depth conversion and the sediment remaining porosity estimated from IODP 381 Site M0079 cores.
Time to depth conversion contributes uncertainty that ranges from 7% at the seafloor to 20% at the basement. Porosity contributes uncertainty that ranges from 8% at the seafloor to 4% at the basement. Estimates of sediment volumes in the high-resolution section range from 4.3 km3 ± 10.3% from 0-15 ka to 7.9 km3 ± 20.1% from 259-294 ka.
We see two stages of increasing sediment accumulation rates over the last 600 ka. Accumulation rates rise from 0.047 ± 20.3% km3/kyr at 592 ka to 0.413 ± 21.0% km3/kyr at 259 ka then from 0.122 ± 15.4% km3/kyr at ~220 ka to 0.302 ± 13.2% km3/kyr at present.
From these preliminary results we will evaluate the relationship between the accumulation volumes and rates in relation to climate, i.e. changes in precipitation due to global glacial-interglacial cycles, and regional tectonics, i.e. the simultaneous uplift of the drainage area and subsidence of the basin.
How to cite: Di Paolo, C. C., Gawthorpe, R. L., Huismans, R. S., Rouby, D., and Nixon, C. W.: High-resolution basin-wide sedimentary budget quantification during periods of high-frequency climate change in the active Corinth Rift system, central Greece, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19973, https://doi.org/10.5194/egusphere-egu26-19973, 2026.
Grain size of clastic sediment is generally regarded as the product of physical processes active during transport and deposition. Here we investigate the influence of the parent rock lithology on the original grain-size of daughter sediments by combining in situ and laboratory analyses of outcrop, detritus and sediments.
As study site we chose a relatively small catchment area (147,7 km2 planar, 185,4 km2 accounting for elevation) located in Valle di Fassa (Dolomites, IT). This is done to consider the analysed samples representative of the sediment produced at the source, disregarding the effect of sediment transport. In this area three main lithologies outcrop, all in similar proportions: (a) dolostones, (b) mafic to intermediate volcanics and (c) limestones and sandy limestones. We: i) quantified the source rock distribution with a GIS-based geospatial analysis, ii) analysed the outcrops of these lithologies with 3D drone photogrammetry and in-situ Schmidt hammer rebound test to estimate fractures, bedding and rock strength, iii) performed image analysis and sieving to obtain grain-size of detritus collected at the base of outcrops, and iv) finally, performed both grain-size and compositional analyses of each grain-size fraction between 16 cm and 0.075 mm on the sediment samples collected from a sandy-gravelly fluvial bar of the Avisio River reaching sediments from the studied outcrops.
The results obtained show a significant relationship between outcrops fracture spacing, grain size of detritus, and grain size and composition of river sediment: dolostones tend to be over-represented in the gravelly sediments, while volcanic grains dominate the sandy grain-size. Still, none of the sediment samples analysed has a similar proportion between the three lithologies, as the one of the GIS-derived catchment area‘s.
These findings suggest that sediment grain size at the origin is strongly controlled by lithology-dependent weathering processes, active on parent rocks. This is expected to have a significant effect on facies development along the routing systems of clastic sediments. In addition, different grain-sizes preserve very different images of the same source area. Therefore the control of parent-rocks lithology on daughter sediment grain-size must be carefully considered when approaching provenance studies aimed at paleo-geological reconstructions as well as for facies tract predictions.
How to cite: Pezzoli, S., Testa, G., Foletti, M. G., Menegoni, N., Di Giulio, A. S., and Toscani, G.: Sediment grain size vs. parent rocks lithology: insights from the Avisio River and its drainage area (Dolomiti, Italy) , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11898, https://doi.org/10.5194/egusphere-egu26-11898, 2026.
Located at the entrance to the sedimentary basin, alluvial fans are key depositional systems in which fluvial responses to external forcing are commonly preserved in the gravel and sand fraction of the stratigraphic record. It has long been observed that upstream catchment area has an impact on fan extent, incoming sediment flux, and subsequent deposition rates (Bull, 1977). Numerical modelling results suggest that catchment size can affect the autogenic dynamics of channel incision and mobility inducing high topographic variation across the fan, transient deposition, and more rapid grain size fining in systems where the downstream drainage area is greater than the upstream source catchments (Wild et al. 2025). However, the extent to which these internal dynamics are expressed in real-world fan grain size records and any geometric thresholds within the landscape remains poorly constrained. In an area with comparable external forcing (e.g. limited tectonic activity, comparable lithology and base-level, and comparable mean annual precipitation) producing fans in a state of sediment bypass near Kowarib, Namibia, we tested additional internal dynamics and geometric (e.g. catchment area and topographic) correlations with grain size fining.
The goal of our approach is to quantify internal controls observed within the landscape evolution model, GravelScape (Wild et al. 2025), on the gravel grain size fining record of real-world unconstrained alluvial fans. We implemented a geospatial analysis of high resolution (1 m) DEM, multispectral remote sensing imagery, and analysis of field captured channel bed images and bank measurements. To measure gravel grain sizes, we implemented the machine learning ImageGrains algorithm (Mair et al, 2024) on field sampled imagery from the main channel of three fans in the northern interior of Namibia. We expanded the geospatial analysis to nine Kowarib fans draining the same mountain range as the field sampled fans to provide greater geometric context on the area. Preliminary results indicate a difference in fan profile shape (convex vs concave) draining larger catchments (> 1 km2) with less grain size fining in these systems even after normalization by depositional length. The concave fans draining the smaller catchments (<1 km2) often displayed steeper topography, patches of exposed bedrock in their main channel, patches of thick sedimentation, high rugosity (variation across the fan surfaces-channel incisions), and more rapid grain size fining. The convex fans draining the larger catchments (>1 km2), displayed a more consistent sedimentation layer throughout the main channel, less topographic variation (down and across) the fan and less grain size fining. A landscape evolution model is then used to compare downstream responses in fan development and grain size fining across different catchment–basin geometries, isolating the effects of variations in sediment supply and fan evolution time or internal, autogenic, depositional dynamics within the fan.
Bull (1977). Progress in Physical Geography: 1(2). doi.org/10.1177/030913337700100202
Mair et al. (2024) ESPL :49(3). doi.org/10.1002/esp.5755
Wild et al. (2025) ESurf: 13(5). doi.org/10.5194/esurf-13-889-2025
How to cite: Wild, A., Mair, D., do Prado, A., Jaimes Gutierrez, R., Prieur, M., Rezwan, N., Mapani, B., Nduutepo, A., Walk, J., Krieger, J., Guhe, F., Chatty, A., and Lehmkuhl, F.: Catchment and fan geometry controls on grain size fining in northwestern Namibia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6689, https://doi.org/10.5194/egusphere-egu26-6689, 2026.
Sediment routing systems record grain size changes from source to sink. Sediment grain size decreases downstream due to the selective deposition of sediment, but can also increase when material is added from tributaries. Importantly, quantifying downsystem changes in grain size helps elucidate the dynamics of sediment routing systems in the geological past, and understand the spatial heterogeneity of deposited strata.
The Sherwood Sandstone Group (SSG) and Mercia Mudstone Group (MMG) of the British Isles are regionally significant units deposited during the breakup of Pangea. The SSG is a key unit for groundwater resources, geothermal energy and carbon capture and storage. For our source-to-sink analysis, we use a chronostratigraphically defined interval of the SSG and MMG, which was deposited by a long-distance dryland river system active during the mid-Triassic (c.240 Ma).
We interpret 130 sections through the SSG and MMG using geophysical well logs, outcrops and cored boreholes. Using these data, existing palaeogeographies and isopach maps, we generate upsystem-to-downsystem volumetric grain size profiles (gravel, sand and mud) for this sediment routing system. We convert these profiles into a dimensionless mass balance framework. These results provide a detailed characterisation of this river system and its deposits, supported by existing studies on sediment routing, sandstone petrography and quantitative paleohydrology. Crucially, we are able to explore the spatial dynamics of this sediment routing system, including the locations of sediment inputs and downsystem sediment bypass, demonstrating the generic utility of our approach in reconstructing ancient source to sink systems.
How to cite: Yan, X., Hampson, G. J., and Whittaker, A. C.: Grain size fractionation in a Triassic dryland fluvial system: the Sherwood Sandstone Group, UK, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19646, https://doi.org/10.5194/egusphere-egu26-19646, 2026.
The Paleocene and Early Eocene stratigraphic succession in the central North Sea records a period of substantial tectonic uplift and several climatic perturbations in the adjacent hinterland. Eastern progradation of the UK shelf and a series of turbidite deposits have previously been linked to several phases of inferred regional uplift. The regional uplift phases caused major increases in sedimentation rates in the North Sea basin and an extensive reorganization of the sediment routing systems. The relative importance of allogenic and autogenic forcings on the sediment supply, depositional patterns and basin-wide geomorphology, however, remains debated. Several authors have suggested that the uplift is a response to activity of the Icelandic Plume.
This study incorporates high-resolution 3D seismic and well-log data to conduct a regional reconstruction of the Paleocene – Early Eocene stratigraphic succession in the central North Sea. We investigate key stratigraphic surfaces to link the temporal along-strike variability of erosion and deposition in the Montrose and Moray Groups. Seismic attribute analysis of over 90 000 km2 of 3D seismic data is used to investigate the geomorphology and paleogeography of several interpreted intervals, including clinoform geometry, shelf-edge trajectories, submarine channels, and deep-marine fan systems, providing insights into sediment transport pathways and depositional processes.
Preliminary results indicate pronounced along strike variability throughout the Paleocene and Early Eocene in sediment thickness and geomorphology. In the earliest Paleocene the basin was dominated by deep-marine sedimentation, with several submarine fans being deposited in the Moray Firth, Southern Viking Graben and Central Graben. Throughout the Paleocene, the shelf prograded and the basin was infilled. Thick clinoforms, large submarine fans, and extensive shelf progradation during key stratigraphic intervals indicate increased sediment input, suggesting changes in sediment connectivity between hinterland source areas and offshore sinks driven by variations in erosion and runoff. The presence of erosional fluvial networks incised into older marine sediments indicates subaerial conditions during the latest Paleocene to Early Eocene in the Moray Firth. The subaerial erosional networks are associated with a progradation of the coast by tens of kilometers, suggesting a major base-level change, driven by extensive tectonic uplift. This enables detailed observations of geomorphic responses to tectonic and climatic forcings in the entire fluvial to deep-marine sediment routing system.
How to cite: Mangersnes, K., Gawthorpe, R. L., Sømme, T. O., and Huismans, R. S.: Regional stratigraphic and geomorphic evolution of the Paleocene - Early Eocene in the Central North Sea , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10601, https://doi.org/10.5194/egusphere-egu26-10601, 2026.
Located in the central Sichuan Basin, the Tianfu Gas Field exhibits multi-storied gas-bearing features within the Shaximiao Formation. However, the exploration and development of its tight gas reservoirs remain at a preliminary stage, necessitating enhanced understanding of the formation's depositional systems and sandstone distribution patterns.Therefore, this study focuses on the Sha21 submember in the Jinqian 5H well block of Tianfu Gas Field as the research target. Integrating regional geological background with 3D seismic data, drilling/logging data, and laboratory analyses, using a well-seismic combined approach,we systematically investigated the planar distribution and evolutionary characteristics of the depositional system in the study area. the study provides a reference case for sequence architecture analysis and reservoir prediction in similar fluvial sedimentary regions.
Research has shown that paleosoil geochemical analysis and mineral characteristics indicate that the Sha21 submember was in an arid to semi-arid climate environment. Field profiles and on-site core observations show that this period was a typical fluvial sedimentary structure,the entire sequence formed in a regressive depositional setting, accompanied by periodic fluctuations of the base level. Stratigraphically, the submember can be divided into four 4th-order sequences (medium-term cycles: MSC1-MSC4), corresponding to four sandstone units (F1 through F4) respectively. During the deposition of the F1 sand unit,the base level began to drop, and the source supply was relatively stable, mainly consisting of meandering rivers or low-sinuosity channels . During this stage, the accommodation space was relatively high, the channel incision was deep but lateral migration was limited, and the sand bodies showed relatively narrow (mostly <1km), consistent continuity and clear striped distribution characteristics. The F2 sandstone unit deposition period witnessed rapid base-level drop with markedly increased sediment supply and reduced accommodation space. During this phase, channels exhibited intense lateral migration and aggradation, resulting in significantly widened fluvial sandbodies (reaching 2-3 km in width) with extensive distribution and excellent continuity. During the F3 sandstone unit depositional period, the base-level drop slowed down and even experienced short-term rises while sediment supply decreased, leading to weakened fluvial energy. Local tectonic activity caused the migration of the channel system westward, forming relatively narrow (mostly <1km) yet still continuous channel sandbodies. During the deposition of the F4 sandstone unit, the base level had dropped to its lowest position with sharply reduced accommodation space, while fluvial energy significantly weakened and sediment supply further decreased. These conditions restricted sediment transport to distal areas, forcing lateral expansion and vertical stacking, resulting in proximal concentration of sandbodies with shortened lateral extension.
The sedimentary evolution in the study area was primarily controlled by three interrelated factors: (1) phased base-level changes within a regressive background, (2) fluctuations in sediment supply, and (3) the consequent dynamic feedback mechanisms affecting fluvial energy and channel morphology.The variations in channel width and morphology, along with their planar migration patterns, comprehensively document the fluvial system's response to changes in the accommodation-to-sediment supply ratio (A/S).
Keywords: Jinqian 5H well block; Sha21 Submember; sedimentary characteristics; sandstone distribution patterns
How to cite: Zhang, Z., Wang, Z., and Jurado, M. J.: Research on Fluvial Depositional Evolution and Sandbody Distribution Patterns of the Sha21 Submember in Jinqian 5H Well Block, Tianfu Gas Field, Sichuan Basin, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6524, https://doi.org/10.5194/egusphere-egu26-6524, 2026.
The East Antarctic Ice Sheet is the largest ice-sheet on the planet, developed since the Late Eocene upon a puzzle made of cratonic plateaus, mountain belts and intracontinental basins. The flow pattern of the waxing Ice Sheet is controlled by the preexisting landscape, mainly where high-relief topography was already developed. On the eastern limit of the East Antarctic Ice Sheet facing the Ross Sea, the Transantarctic Mountains acted as a barrier limiting the early growth of the ice sheet. Outlet glaciers drained ice flows across the high elevation rift flank enlarging fjord-like valleys by selective erosion, whose efficiency changed also as a consequence of the variable Oligocene-Miocene climate.
Uncertainty exists whether or not high-relief topography predates major ice growth in the Transantarctic Mountains. Here, landscape is expected to play a critical role, modulating flow directions over a preexisting drainage network. In addition, pre-Cenozoic tectonic inheritances controlled the location of highs and lows in the topography contributing to focus the glacial flow. The southern Victoria Land is the sector of the Transantarctic Mountains which offer the most complete bedrock exposition in deglaciated areas, and offshore drill cores reaching depths of up to 850 m below sea floor just off the margin. The detrital record from 36 to 18 Ma corresponds to the Eocene-Oligocene Transition and the onset of the Ice Sheet growth.
In this study, we applied a multi-analytical approach to constrain sediment provenance using new datasets of detrital apatite fission-track thermochronology and detrital zircon U-Pb geochronology from CIROS-1 drill core. New data are coupled with petrographic description of gravel and sand fractions, facies analysis and revised age model. The source-to-sink analysis of CIROS-1 sediments is compared with Cape Roberts Project core record to reconstruct the environmental conditions and geomorphic setting of the two main valleys draining ice through Dry Valleys. The comparison between detrital signals and bedrock information suggests a change in the erosive style and the elevation of the sediment source through the Eocene-Oligocene. The Eocene catchment area located along the coast was reorganized by the overriding outlet glaciers sourced from the inner Transantarctic Mountains. The topographic divide retreated in Dry Valleys where glacial erosion was more efficient as recorded in provenance data. Results highlight how the preexisting mountainous landscape conditioned ice flow during early EAIS expansion and provide new constraints on the timing and magnitude of landscape modification along the TAM rift flank.
How to cite: Fioraso, M., Zurli, L., Olivetti, V., Perotti, M., Sandroni, S., McKay, R., Naish, T., Cornamusini, G., and Zattin, M.: Detrital record unveils the role of topography in the Antarctic Ice Sheet growth , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19505, https://doi.org/10.5194/egusphere-egu26-19505, 2026.
Understanding how fluvial systems respond to geological controls is challenging due to their sensitivity to a wide range of environmental conditions. These factors determine the characteristics of preserved stratigraphic successions, which may not be accounted for by traditional continental sequence-stratigraphic models. Such models tend to be overly simplistic in the way they consider morphodynamic behaviours, especially for setting where distinct river systems, fed by distinct sediment sources and exhibiting different geomorphic dynamics, interact with each other. Moreover, the extent to which different geomorphological river types are preserved in the stratigraphic record has not been fully documented.
This study aims to elucidate the dynamic interactions and contrasting evolution of adjoining axial and transverse river systems through the study of Quaternary successions and geomorphic elements across a transect of the central Po Valley (Northern Italy). The Po Basin is an asymmetric alluvial foredeep basin and represents an excellent laboratory for this purpose, because it records the geological history of rivers draining the Alps and the Apennines, and converging in the axial Po River channel belt.
A comprehensive geological dataset is constructed by integrating field-based mapping of geomorphological, sedimentological and pedological features with shallow-subsurface borehole observations and remote-sensing data. Petrographic and micromorphological data are being collected with which to undertake analyses of sediment provenance and pedogenetic processes. A chronostratigraphic framework is being erected based on radiometric and luminescence dating, palaeomagnetic data and archaeological evidence.
The results shed light on the contrasting geomorphological and stratigraphic features in the postglacial fluvial evolution of the central Po Plain. The northern alpine tributaries are characterized by incision-dominated dynamics, driven by a marked decrease in sediment supply following the transition from proglacial outwash systems to the postglacial configuration, in which the development of pre-Alpine lakes has been of considerable importance, effectively trapping detritus from upstream catchments.
By contrast, southern rivers draining Apennine catchments have built a postglacial unit dominated by widespread aggradation, characterized by the coalescence of small fluvial fans traversed by alluvial ridges linked with a topographic control on sediment distribution via repeated avulsions.
This asynchronous evolution of aggradational and degradational phases reflects contrasting sedimentary and geomorphic trends driven by differences in sediment supply rates and delivery mechanisms. Indeed, these findings provide a valuable framework for interpreting the stratigraphic architecture of Quaternary successions of the Po Basin, and for comparing the observed post-15 ka evolution with traditional sequence stratigraphic models (LST–TST–HST transition).
This research enables a critical evaluation of the applicability of sequence stratigraphic models in continental settings, emphasizing the necessity for more sophisticated models that account for spatial and temporal variability in fluvial responses to external forcings. Current work seeks to expand this study to successions and landforms recording the earlier Pleistocene evolution of these river systems. By highlighting these processes, this study focuses on the key role of source-to-sink approaches for understanding fluvial system dynamics in continental settings.
How to cite: Simoncelli, L., Colombera, L., and Basilici, G.: Contrasting the postglacial morphodynamic evolution of Alpine and Apennine river systems in the central Po Valley, Italy, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4452, https://doi.org/10.5194/egusphere-egu26-4452, 2026.
Natural arsenic concentrations in groundwater locally exceed drinking water standards, raising public health concerns. Preventing its release requires identifying its 3D distribution in rocks and water–rock interactions. We address this through a source-to-sink approach applied to predicting arsenic distribution in Miocene sedimentary deposits of the southwestern Paris Basin, where geogenic arsenic is present and monitored in aquifers (e.g., lacustrine deposits of Beauce Fm. – Aquitanian) underlying sedimentary cover (fluvial deposits of Sables et Argiles de Sologne Fm. – Burdigalian to Pliocene).
Our approach combines source-to-sink tools, chiefly geomorphology and sedimentology, with arsenic geochemistry in order to trace arsenic transfer from source areas to sedimentary reservoirs. It involves: (1) identifying sources coupling the reconstruction of paleoreliefs from planation surfaces and paleodrainage areas and characterizing arsenic concentrations in the drainage areas using pXRF ; (2) characterizing depositional environments, including sedimentary facies and their actual and past physicochemical conditions, and the associated arsenic content in terms of abundance, speciation, carrier phases within each facies (pXRF, sequential extractions, μXRF and ICP-MS), and mechanisms of arsenic retention (sorption, complexation and mineral precipitation).
Two source-to-sink systems have been identified in our study: (i) an Aquitanian endorheic lake system and (ii) a mid-Miocene terrigenous system. The Aquitanian system is fed by the surrounding reliefs, leading to the remobilization of arsenic contained in older sedimentary series. Arsenic is sequestered in deep-lake facies, where it is mainly trapped by framboidal pyrite and organic matter under reducing conditions. The mid-Miocene system reflects a reorganization of the drainage basins, resulting in the recycling of older formations and material derived from the northern Massif Central (MCF). Arsenic is predominantly carried by pyrite in reduced floodplain facies. Tectono-hydrogeological destabilizations since the Tortonian have promoted the oxidation of these reduced sedimentary reservoirs, the release of arsenic in groundwater and partial precipitation of secondary arsenic carrier phases.
This study highlights the role of geomorphology and sedimentology in controlling arsenic drainage and trapping, and establishes a link between initial trapping and current groundwater quality. (ANR-22-PEXO-0010 – PEPR One Water Eau bien commun research program).
How to cite: Alus, L., Guillocheau, F., Lasseur, É., Briais, J., Robin, C., Lions, J., and Lerouge, C.: Source-to-sink of natural arsenic in Neogene sedimentary systems of the south western Paris Basin, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10082, https://doi.org/10.5194/egusphere-egu26-10082, 2026.
The Congo Basin is the second-largest river basin in the world. It is characterized by extensive tropical forests, wetlands, and floodplains that together form one of the largest terrestrial carbon reservoirs on Earth, including the world’s largest tropical peat complex beneath the swamp forests of the Cuvette Centrale. The low-relief morphology and extensive floodplain systems of the basin strongly influence the storage, transformation, and transfer of water, sediment, and organic matter. Consequently, export dynamics from different parts of the Congo Basin remain incompletely understood, including the sourcing and export of clastic sediment and associated particulate organic carbon. Here, we use radiogenic isotope ratios of strontium, neodymium, and lead together with bulk organic carbon (stable and radiocarbon isotopes) and nitrogen isotope data, to constrain the export of clastic and organic particulates from contrasting geomorphic and ecological settings through the Congo River's fluvial network. We analyzed a transect of tributaries spanning peat-dominated swamp forests, evergreen forests, and mixed forest-savanna catchments. Underlying source lithologies range from Archean cratonic rocks to Cretaceous units and Quaternary sediments within the swamp regions of the Cuvette Centrale. We then compare the modern river data with a downcore marine record from Congo Fan deposits to assess how Holocene climate change affected sediment routing dynamics and the preservation of provenance signals from the Congo Basin in the stratigraphic archive. This study provides new insights into the sediment and organic carbon routing systems within the Congo Basin and its connection to the marine sedimentary record.
How to cite: Menges, J., Schefuß, E., Meixner, A., Garcin, Y., Bouka, G. U. D., Abaye, C., Guardiola, M., Bouillon, S., Stroobandt, Y., Mollenhauer, G., Grotheer, H., and Kasemann, S. A.: Tracing sediment sources and export dynamics in the Congo River Basin using radiogenic isotopes, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19029, https://doi.org/10.5194/egusphere-egu26-19029, 2026.
