TS4.3 | Quantifying the interactions of tectonics, topography and surface processes in orogen-sedimentary basin systems and their links to geodynamic forcings
Quantifying the interactions of tectonics, topography and surface processes in orogen-sedimentary basin systems and their links to geodynamic forcings
Co-organized by GD6/GMPV10
Convener: Yanyan WangECSECS | Co-conveners: Romano ClementucciECSECS, Attila BalázsECSECS, Sebastien Carretier, Zoltán Erdős, Duna Roda-BoludaECSECS, Sebastian G. WolfECSECS
Orals
| Mon, 15 Apr, 10:45–12:30 (CEST)
 
Room D1
Posters on site
| Attendance Mon, 15 Apr, 16:15–18:00 (CEST) | Display Mon, 15 Apr, 14:00–18:00
 
Hall X2
Orals |
Mon, 10:45
Mon, 16:15
The intricate links between crustal deformation, mantle dynamics, and climate-driven surface processes have long been acknowledged as primary drivers shaping the evolution of orogens and sedimentary basins. Tectonics, climate, and surface processes all leave fingerprints on modern topography, making it difficult for researchers to univocally characterize their contribution to shaping landscapes. Unraveling the distinct roles of crustal, deep mantle, and climatic forcings poses a formidable challenge due to the vast range of spatial and temporal scales involved in these processes. The comprehensive study of such dynamic systems necessitates a multidisciplinary approach, integrating observational data from field studies, geophysical and subsurface data analysis, quantification methods of rock or surface uplift rates and erosion rates, as well as both analogue and numerical modeling techniques.

We invite contributions that delve into the exploration of orogenesis and sedimentary basin evolution, emphasizing their intricate connections to surface processes, and the underlying dynamics of crustal and mantle forcings. Furthermore, we encourage studies utilizing a diverse array of methodologies, including analogue and numerical models, along with quantitative techniques like cosmogenic nuclides and thermochronometers, as well as field studies. This collective effort aims to quantify and elucidate the intricate coupling between tectonics and surface processes in these dynamic geological systems and the links to mantle forcings.

Orals: Mon, 15 Apr | Room D1

Chairpersons: Yanyan Wang, Romano Clementucci, Duna Roda-Boluda
10:45–10:50
10:50–11:00
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EGU24-7286
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Virtual presentation
From Dome to Duplex: An Intriguing Case of Convergent Gravitational Collapse in Central Australia
(withdrawn after no-show)
Patrice Rey, Youseph Ibrahim, Donna Whitney, Christian Teyssier, Françoise Roger, Valérie Bosse, and Bénédicte Cenki
11:00–11:10
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EGU24-8980
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On-site presentation
Qihua Cui, Pengpeng Huangfu, and Zhong-Hai Li

The rotational of rigid blocks within continental interiors, distant from plate convergence boundaries, represents a peculiar phenomenon with unclear dynamics. The Tarim block, characterized as a rigid Precambrian entity in Central Asia, is surrounded by the Tibetan–Pamir plateau to the south and the Tian Shan mountains to the north. Geophysical data strongly indicate a significant clockwise rotation of the Tarim block during the Cenozoic era. Simultaneously, distinctive deformation patterns and associated topographic responses are observed between the western–central and eastern Tian Shan regions. The intricate relationship among the India-Asia collision, Tarim's rotation, and Tian Shan's responses remains insufficiently constrained. In this study, we constructed a series of large-scale, high-resolution 3-D numerical models to study the mechanisms and effects of Tarim rotation. Our model results reveal that the collision between the advancing Indian lithosphere and the southwestern rim of the Tarim block triggers a clockwise rotation of the Tarim block. Subsequently, this rotation induces varied deformation responses along the strike of Tian Shan—resulting in heightened compression and significant uplift in central Tian Shan due to convergence, while eastern Tian Shan experiences less compression and moderate uplift attributed to divergence. Thus, the Tarim rotation emerges as an essential linkage, connecting the evolutionary dynamics of the Tibetan plateau with the far-reaching activation of Tian Shan. This research provides valuable insights into the geodynamic processes shaping continental interiors, with implications for broader tectonic frameworks and technological applications.

How to cite: Cui, Q., Huangfu, P., and Li, Z.-H.: Mechanisms and effects of Tarim rotation: 3-D thermo-mechanical modeling, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8980, https://doi.org/10.5194/egusphere-egu24-8980, 2024.

11:10–11:20
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EGU24-5514
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ECS
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On-site presentation
Patrick Makuluni, Juerg Hauser, and Stuart Clark

The geological histories of passive margin basins are dominated by tectonically induced vertical and lateral motions that control sediment transport and the development and distribution of resource systems within the basins. However, the upward (uplift and exhumation), downward (burial and subsidence) and lateral (extension, rifting and potential inversion) motions are rarely analysed together. Exploration models built from basin evolution models that include only the vertical dimension may contain larger uncertainties than those that combine lateral and vertical motions. Based on a case study, our research suggests that the combination of analyses can improve the accuracy of basin evolution models and help optimise exploration models. 

Here, we present a case study for the basin evolution model for the Northern Carnarvon Basin that incorporates data from such a combined vertical and lateral motion analysis. Backstripping and decompaction techniques were used to analyse subsidence in more than 200 wells to build the basin’s subsidence and sediment evolution maps. These maps were then used to analyse lateral motions associated with the intraplate rift development in the region. In parallel, we analysed exhumation using compaction and vitrinite reflectance analysis techniques on porosity, sonic logs and paleotemperature data from 210 wells. Our combined analyses revealed seven critical periods of basin development from the Triassic to the present. The Triassic Period was dominated by thermal subsidence and sedimentation within the south-western parts. High subsidence (~ 90 m/Ma) and sedimentation were dominant in the Early and Mid-Jurassic, coinciding with the intraplate rifting of up to ~8 mm/yr, which produced the major sub-basins in the southern and southeastern parts of the basin. This was followed by Callovian exhumation that removed up to 1500 m of sediments from the western part of the basin. The Cretaceous was dominated by rifting and breakup-related subsidence, truncated by exhumation episodes that removed up to 1000 m of sediment thickness in the southeastern parts of the basin. In the Cenozoic, the basin experienced subduction-related tilting that exhumed the southern part while the northeastern parts subsided. Our study has shown that integrating the vertical and lateral motions presents a more accurate and complete basin evolution model with the potential for improving the optimisation of basin exploration.

How to cite: Makuluni, P., Hauser, J., and Clark, S.: Dynamic Evolution of the Northern Carnarvon Basin: An Integrated Kinematic Approach, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5514, https://doi.org/10.5194/egusphere-egu24-5514, 2024.

11:20–11:30
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EGU24-17907
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Virtual presentation
Alexandra Muntean, Boudewijn Ambrosius, Eduard Ilie Nastase, and Ioan Munteanu

Abstract

      The Earth's surface is continuously transformed, with deep and superficial processes contributing to the present-day morphology. Evaluating the contribution of each process and interaction between tectonics, climate, and human activities is difficult, especially in areas with relatively low crustal deformation.

      With this study, we aim to better understand the tectonic and sub-surface geodynamic processes that result in (small) surface motions in Romania. We are particularly interested in the Eastern Carpathians Bending Zone (Vrancea region), where strong deep earthquakes occur. Furthermore, we are focused on the interaction between the Eurasian, and Aegean tectonic plates. For this purpose, we processed more than 20 years of cGPS data from various networks in Romania (more than 100 stations), using the GipsyX software. To put our results in a broader perspective, we also included similar results published in open-source online literature including countries around Romania. Combining all these solutions we generated a velocitiy horizontal and vertical velocity fields for this extended region. All solutions were converted to the Eurasian tectonic reference plate in the ITRF14 plate rotation model.

      We find that in general, the horizontal velocity vectors in Romania have small values, ranging from 0.0 mm/yr in the north to 1.5 mm/yr in the south, and notably, the majority of stations indicate a subtle yet significant downward motion of 1.0 -2.0 mm/yr. In contrast, to our expectations, we did not find any significant horizontal and vertical motions in the Vrancea region. The horizontal motions exhibit a strong, generally southward, and gradually increasing trend, starting south of the South Carpathians. The trend is in the direction of the tectonic plates in southeast Europe. It means that the intraplate deformation zone extends to south Romania. The observed patterns contribute to our understanding of intraplate deformation and emphasize the need for continued regional research.

Keywords: crustal deformations, GPS, geophysics, tectonics 

 

Acknowledgments

This paper was carried out within Nucleu Program SOL4RISC, supported by MCI, project no PN23360101, and PNRR- DTEClimate Project nr. 760008/31.12.2023, Component Project Reactive, supported by Romania - National Recovery and Resilience Plan

How to cite: Muntean, A., Ambrosius, B., Nastase, E. I., and Munteanu, I.: 3D Velocity field of Romania derived from more than 20 years of continuous GPS observations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17907, https://doi.org/10.5194/egusphere-egu24-17907, 2024.

11:30–11:40
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EGU24-17337
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On-site presentation
Jose Miguel Azañon, Jorge Pedro Galve, Daniel Ballesteros, Jose Vicente Perez-Peña, Patricia Ruano, Fernando Garcia-Garcia, and Guillermo Booth-Rea

Tearing at the edges of subducted slabs permits the migration of narrow orogenic arcs. Dynamic models predict that the active segment of subvertical tears migrates in the sense opposite subduction modifying the topography and tectonic regime along its path. However, the effects of slab tearing on surface deformation and landscape evolution, remains virtually unexplored. Here we show the landscape response to slab tearing, including drainage development and reorganization in the Betics, with analogies to the southern Caribbean arc. After approximately 400 km of slab tearing since 10 Ma the Betics show a transient topography with positive residual values over regions stripped from their subcontinental lithospheric mantle and negative anomalies outboard of the tear. The landscape evolves through crustal shortening and flexural uplift in the foreland of the active tearing segment producing land emergence and drainage development, with fluvial diversion around uplifting structures. Slab pull and orogen transverse extension inboard the active-tearing segment foster basin development followed by emergence and drainage reorganization by fluvial incision and capture. Mantle upwelling, flexural rebound and further extension affects teared regions, driving positive residual topography amplified in the footwall of extensional domes. Mantle flow around the slab drives uplift hundreds of km away from the slab edges.

How to cite: Azañon, J. M., Galve, J. P., Ballesteros, D., Perez-Peña, J. V., Ruano, P., Garcia-Garcia, F., and Booth-Rea, G.: Landscape response at the edge of a tearing slab, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17337, https://doi.org/10.5194/egusphere-egu24-17337, 2024.

11:40–11:50
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EGU24-4640
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Highlight
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Virtual presentation
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Pietro Sternai, Sébastien Castelltort, Pierre Bouilhol, Lucas Vimpere, Léa Ostorero, Mubashir Ali, Luca Castrogiovanni, Bram Vaes, and Eduardo Garzanti

Cenozoic climate trends are classically ascribed to variations of the geological carbon cycle related to Neo-Tethyan geodynamics. It is widely agreed that the collision of India and Arabia with Asia and associated mountain uplift enhanced erosion and global silicate weathering rates, ultimately driving post-50 Ma climate cooling. Cenozoic climate trends, however, involve major events of global warming in the early Paleogene (~60-50 Ma), a period that preceded rapid mountain uplift by about 30 Ma and that was characterized by a climax of arc magmatism profoundly affecting the surface CO2 budget and consequently climate. We present new measurements of mercury and carbon-isotope anomalies documented in the sedimentary archive, together with pre-eruptive CO2 budgets of Neo-Tethyan magmas encompassing the India-Asia and Arabia-Asia collision. We also show new forward modeling of the Neo-Tethyan geodynamics and inverse modeling of the Cenozoic surface CO2 budget which, tied to these new observational constraints, allow us to quantify magmatic CO2 emissions associated with the collision of India and Arabia with Eurasia. We demonstrate through such comprehensive and interdisciplinary approach that CO2 emissions associated with magmatic pulses induced by subduction of Neo-Tethyan lithosphere as well as of Indian and Arabian passive-continental-margin successions exerted a primary control on early Cenozoic climate changes.

How to cite: Sternai, P., Castelltort, S., Bouilhol, P., Vimpere, L., Ostorero, L., Ali, M., Castrogiovanni, L., Vaes, B., and Garzanti, E.: New constraints on the Neo-Tethyan carbon cycling and its forcing of early Cenozoic climate, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4640, https://doi.org/10.5194/egusphere-egu24-4640, 2024.

11:50–12:00
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EGU24-1067
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ECS
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On-site presentation
Gerald Raab, John Gosse, and Alan Hidy

Measuring the topographic relief evolution over hundreds of thousands to million-year timescales remains challenging. Current approaches use a mix of basin stratigraphy, numerical modelling of terrestrial cosmogenic nuclide (TCN) exposure ages on strath terraces, and exhumation histories based on thermochronology or drainage basin evolution. Yet, even a combined mix of these methods is incapable of quantifying the rate changes with precisions needed to differentiate climate from tectonic drivers over multiple glacial cycles and longer timescales.

The recently conceived muon-paleotopometry (MPT) approach is tailored to close the methodological gap of determining relief generation. MPT exploits the dependence of cosmic ray muon flux on crustal shielding depth. The spatial concentration pattern of multiple muon-induced TCN measured along a near-horizontal transect under valleys and peaks relates directly to the history of changes (positive or negative) in crustal thickness. MPT allows paleotopometry measurements above the sample datum over an isotope-specific monitoring duration. By sampling at depths of hectametres, long-lived TCN (e.g., 10Be, 26Al) are not sensitive to minor short-term (<105-yr) changes owing to cut and fill terraces or transgressions. For instance, the horizontal samples will have similar muon production histories. At this depth, only fast muon interactions and radiogenic or nucleogenic pathways are likely, and only high-energy cosmic ray particles can penetrate, dodging variations in geomagnetic and solar effects and simplifying the interpretation of concentrations along the transect.

We provide an overview of this new method, starting with the theoretical concept, the encouraging proof-of-concept results by Dalhousie (M. Soukup, Hon. Thesis, 2017), the laboratory needs for measuring low TCN concentrations at great depths (>150 m) and update on the progress for the current large-scale relief investigation of the European Alps.

How to cite: Raab, G., Gosse, J., and Hidy, A.: Conceptual proof, current application, and lab procedures to quantify crustal thickness variations with muon paleotopometry, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1067, https://doi.org/10.5194/egusphere-egu24-1067, 2024.

12:00–12:10
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EGU24-13841
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On-site presentation
Todd A. Ehlers and Sean D. Willett

Quantifying rates and magnitudes of topographic change across timescales requires diverse observational and modeling techniques.  Low-temperature thermochronometer methods are a powerful tool for quantifying denudation rates, paleotopography, and/or the kinematic history of orogens over geologic timescales.  Parallel to thermochronometer technique development, a range of thermal, kinematic, and erosion modeling approaches are available to interpret tectonic and surface processes from thermochronometer data. However, differing thermal modelling approaches exist in the literature and often lead to the question of which approach is most appropriate, and when?

This presentation addresses the diversity of thermo-kinematic and erosion modelling approaches available to quantitatively interpret topographic change or tectonic processes from thermochronometer data. Emphasis is placed on deciphering the different approaches available and which approach is suitable for the scientific questions asked (e.g., topographic change, tectonic/faulting history, etc.) in diverse geologic settings.  Thermo-physical factors explored include the appropriate model spatial dimension (e.g., 1D, 2D, vs. 3D); the influence of model geometry on geotherms; the importance of constant basal temperature vs. flux basal boundary conditions; transient vs. steady-state geotherms, and how tradeoffs in different parameters (exhumation rate, material properties, boundary conditions) can produce similar thermochronometer ages. The presentation focuses on examples from the literature, ranging from William Thompson’s (Lord Kelvin) founding work on continental geotherms to contemporary numerical modeling approaches.

How to cite: Ehlers, T. A. and Willett, S. D.: Appropriate Thermal Modelling Approaches for Interpreting Topographic and Tectonic Change from Thermochronometer Data (Remembering the Geotherm and 200 years of Lord Kelvin’s legacy), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13841, https://doi.org/10.5194/egusphere-egu24-13841, 2024.

12:10–12:20
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EGU24-15024
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On-site presentation
Liran Goren, Elhanan Harel, Tianyue Qu, Onn Crouvi, Naomi Porat, Hanan Ginat, and Eitan Shelef

It is common to assume that when there are erosion rates and slope gradients across a drainage divide, the divide is prone to migrate and change the drainage area distribution of its bounding catchments. However, direct records of divide migration are exceptionally rare. This raises the following questions: Could the assumption be wrong, and can divides sustain topographic and erosion rate asymmetry over geomorphic and geologic (104– 106 yrs) timescales? And when divides eventually migrate, is the migration driven by endogenic feedback within the basin, or by exogenic forcing, such as climate change?

To address these issues, we study a field area along the escarpments of the Dead Sea plate boundary, Israel, where direct records for divide migration are present in the form of terraces that grade opposite to the channel flow direction. These terraces are interpreted as a record of the divide’s paleo-locations, such that terraces are formed when the divide migrates inland from the edge of an escarpment, inducing drainage reversal and gradually extending the reversed channel that drains toward the escarpment.

Absolute dating of these terraces using luminesces techniques and relative dating using soil chronosequence markers reveal that the terraces become older from the present locations of the divide toward the escarpment, consistent with the interpreted process of their formation. Terrace ages show an average divide migration rate of ~1100 m myr-1 over the past ~230 kyr, supporting active divide migration over timescales of 105 yrs or shorter.

Terrace groups with similar ages indicate ~100 kyr cycles of periods of divide stalling and episodes of rapid divide migration with rates up to fourfold relative to the average rate. We use numerical simulations to explore possible drivers for the inferred divide intermittent dynamics. Simulations show that the dynamics are inconsistent with landscape evolution under uniform environmental conditions due only to internal basin dynamics. Instead, the inferred intermittency is best explained with time-dependent erosional efficiency that is sensitive to global climate change and correlates with regional paleoclimate proxies.

This study provides the first detection of divide migration rate intermittencies at timescales of 104-105 yrs, and the association between divide dynamics and changing climatic conditions. This highlights the potentially significant impact of climate changes on the plan-form evolution of drainage basins.

How to cite: Goren, L., Harel, E., Qu, T., Crouvi, O., Porat, N., Ginat, H., and Shelef, E.: Direct evidence of drainage divide migration reveals intermittent dynamics linked to 100 kyr climate oscillations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15024, https://doi.org/10.5194/egusphere-egu24-15024, 2024.

12:20–12:30
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EGU24-20268
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On-site presentation
Adam Smith, Matthew Fox, Scott Miller, and Leif Anderson

Densification at the base of thickened crust drives lithospheric dripping or delamination. Mountain ranges form due to crustal thickening, and so represent locations where dripping and delamination are likely to occur. Recent studies have implicated dripping continental crust with a variety of different surface expressions, from driving surface uplift to initiating rifting, highlighting the uncertainty associated with our ability to predict the surface consequences of dripping continental crust. The Uinta Mountains in Utah formed during the Laramide orogeny, and despite this period of crustal shortening ending ~50 mya, the elevation of the range, and the form of the river networks draining the range suggest the range has undergone topographic rejuvenation. To investigate the cause of this rejuvenation, we extract map of recent surface uplift from the river networks of the Uintas, and use previously published seismic tomography to investigate the structure of the mantle beneath the range. We identify dripping lithospheric crust beneath the Uintas, and, using a simple isostatic model, are able to reconcile the observed surface uplift with a prediction of surface uplift based on isostatic compensation. The agreement between our observations and our predictions allow us to present a compelling case for delamination driven surface uplift of the Uintas, and show that simple isostatic compensation can explain the surface expressions of delaminated crust. Our observations therefore have important implications for the history of the Uinta Mountains and more generally for our understanding of the long-term evolution of the continents.

 

How to cite: Smith, A., Fox, M., Miller, S., and Anderson, L.: Discovery of lithospheric drip explains topographic rejuvenation of the Uinta Mountains, USA, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20268, https://doi.org/10.5194/egusphere-egu24-20268, 2024.

Posters on site: Mon, 15 Apr, 16:15–18:00 | Hall X2

Display time: Mon, 15 Apr 14:00–Mon, 15 Apr 18:00
Chairpersons: Attila Balázs, Sebastien Carretier, Zoltán Erdős
X2.74
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EGU24-18362
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ECS
Santiago León, Claudio Faccenna, Ethan Conrad, and Víctor A. Valencia

The sediment dispersal patterns at active orogens are highly sensitive to changes in the landscape configuration triggered by the combined effects of deformation, volcanism, and geomorphological processes. Hence, reconstructing source-to-sink systems provides valuable insights into the interplay between deep-seated and surface processes as controls of the coupled development of mountain ranges and intermontane sedimentary basins.

The Oligocene-Miocene evolution of the Colombian Andes has been shaped by subduction tectonics and the collision of an oceanic terrane, which are linked to changes in the kinematics of crustal deformation and the tectono-magmatic history of continental arcs. Nevertheless, the combined effect of such processes on the growth of the Western and Central Cordilleras and the associated intermontane basins remains elusive.

Here, we use a large dataset of detrital zircon U-Pb ages from Oligocene-Pliocene strata of intermontane basins of western Colombia, and available (bio)stratigraphic and structural constraints to reconstruct: i) the regional-scale configuration of source areas and accumulation settings, ii) the sediment routing systems, and iii) the history of basin connectivity. We interpret the sediment dispersal patterns as controlled by the pulsed uplift of the Central and Western Cordilleras linked to a syn- to post-collisional transpressional tectonic regime, and to changes in the drainage network driven by intra-basinal arc-related magmatic activity

How to cite: León, S., Faccenna, C., Conrad, E., and Valencia, V. A.: The role of tectonic, volcanic, and fluvial processes as controls of Neogene intermontane basin evolution in the western Colombian Andes, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18362, https://doi.org/10.5194/egusphere-egu24-18362, 2024.

X2.75
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EGU24-15751
Sascha Brune, Esther L. Heckenbach, Anne C. Glerum, Roi Granot, Yariv Hamiel, Stephan V. Sobolev, and Derek Neuharth

Releasing and restraining bends are complementary features of continental strike-slip faults. The Dead Sea Basin of the strike-slip Dead Sea Fault is a classical example of a releasing bend with an asymmetric, deep basin structure. However, the intrinsic relationship to its northern counterpart, the restraining bend that created the Lebanese mountains, remains unclear.

Here, we present 3D coupled geodynamic and landscape evolution models that include both the releasing and the restraining bend in a single framework. These simulations demonstrate that the structural basin asymmetry is a consequence of strain localization processes, while sediments control the basin depth. Local extension emerges due to strength heterogeneities and a misalignment of faults and the overall stress field in an area where regional tectonics are dominated by strike-slip motion. Furthermore, we reveal a crustal thinning and thickening pattern that intensifies with surface process efficiency. Along-strike deformation is linked through coupled crustal flow driven by gravitational potential energy which is opposed by deposition at the releasing bend and enhanced by erosion around the restraining bend. Due to the generic nature of our models, our results provide templates for the evolution of fault bends worldwide.

How to cite: Brune, S., Heckenbach, E. L., Glerum, A. C., Granot, R., Hamiel, Y., Sobolev, S. V., and Neuharth, D.: 3D interaction of tectonics with surface processes explains fault network evolution of the Dead Sea Fault, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15751, https://doi.org/10.5194/egusphere-egu24-15751, 2024.

X2.76
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EGU24-13770
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ECS
Mengyue Duan, Franz Neubauer, Jörg Robl, Xiaohu Zhou, and Moritz Liebl

Distinct Mountain–Basin coupling systems were formed during the expansion of the Tibetan Plateau into the surrounding low elevation regions in the north, northeast and east. In this study, we focus on the topographic features of the Bogda Mountains–Southern Junggar Basin coupling system on the north of the Tibeau Plateau, which influenced by the N-S orthogonal shortening caused by the uplift of the Tibetan Plateau and northward propagation of deformation away from the India-Asia collision zone. We mainly quantify the influence of uplift of the Tibetan Plateau on the formation of the Bogda Mountains–Junggar Basin coupling system by fluvial geomorphologic analysis based on the digital elevation model analysis and the optically stimulated luminescence (OSL) dating on the Dalongkou river terraces on the northern slope of Bogda Mountains. Together, these morphological analyses show that the high normalized steepness index (ksn) and knickpoints mainly distributed in the western Bogda Mountains. The normalized steepness index (ksn) gradually decreased from west to east, which indicated that the tectonic activity of the western Bogda Mountains is higher. The compiled low-temperature thermochronology data of the Bogda Mountains show a younging trend from west to east, which indicates that the western Bogda uplift started earlier than in eastern Bogda. The difference of the χ values on both sides of the Bogda Mountains is similar, which means the drainage divide of the Bogda Mountains is stable. There are five river terraces distributed on both side of the Dalongkou River. The optically stimulated luminescence (OSL) dating results show that the ages of the T2 river terrace, T3 river terrace, T4 river terrace of the Dalongkou river are 6.2±1.3 ka, 13.1±1.7 ka, and 14.2±2.5 ka, respectively. The incision rate of the Dalongkou river increases upstream from ~1.22 mm/yr close to the southern Junggar Basin, to ~2.1 mm/yr, and to ~6.33 mm/yr in front of the higher Bogda Mountains, which means that the uplift rate of the Dalongkou river increases upstream. We propose a model of upbending of central Bogda Mts. by ongoing Holocene folding, with an inflection point close to the southern boundary to the Junggar Basin. By comparing the geomorphological features of the Bogda Mountains with the North Tianshan Mountains, we conclude that the tectonic uplift intensity gradually decreased from the North Tianshan Mountains to the Bogda Mountain, as well as the gradual accelerated uplift rate of the Bogda Mountains, are influenced by the N-S orthogonal shortening caused by the uplift of the Tibetan Plateau, which is gradually decreasing from west to east.

How to cite: Duan, M., Neubauer, F., Robl, J., Zhou, X., and Liebl, M.: The Northward Expansion of the Tibetan Plateau: Topographic Evidence from the Bogda Mountains—Junggar Basin Coupling system, Northwest China, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13770, https://doi.org/10.5194/egusphere-egu24-13770, 2024.

X2.77
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EGU24-8880
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ECS
Simone Racano, Peter van der Beek, Claudio Faccenna, Victor Buleo Tebar, Domenico Cosentino, and Taylor Schildgen

The study of rock-uplift variations in time and space can provide insights into the processes driving the topographic evolution of mountain belts. The Apennine mountain chain of Italy, one of the more recently developed mountain belts in the Mediterranean region, has undergone a strong Quaternary rock-uplift phase, particularly in the north-central sector, which has shaped the present-day topography. It has long been recognized that drainage systems can record temporal and spatial variations in rock-uplift rates. Specifically, in detachment-limited systems with simple settings (e.g., no significant variations in drainage area over time, and catchments mostly draining perpendicular to regional structures), river profiles can be inverted to reconstruct their history of rock uplift. In this study, we present linear inversions of river profiles from 28 catchments along the eastern flank of the northern-central Apennines. These results are calibrated to infer rock-uplift rates by estimating the value of an erodibility parameter (K) from short-term incision rates and catchment-averaged erosion rates obtained from cosmogenic-nuclide data. Different approaches with constant and variable K have been applied to produce the rock-uplift model that best fits independent geochronological constraints about the uplift of the Apennine belt. Our findings suggest a spatially and temporally variable rock-uplift event that started around 2.5 to 3 Ma, following the last compressional orogenic phase and coinciding with the onset of extension. Furthermore, this rock-uplift pulse migrated southward at a rate of approximately 115 km/Myr. The highest rock-uplift rates (higher than 1.2 km/Myr) are observed in the region encompassing the highest Apennine massifs, such as the Laga Massif and the Gran Sasso Range. These results align with previous studies on Apennine paleoelevations, and they are consistent with numerical models and field evidence from other regions exhibiting rapid rock-uplift pulses and the migration of uplift related to slab break-off. Our results support the hypothesis of a break-off of the Adria slab under the central Apennines and its southward propagation over the last few million years.

How to cite: Racano, S., van der Beek, P., Faccenna, C., Buleo Tebar, V., Cosentino, D., and Schildgen, T.: Tectonic driving mechanism of Quaternary rock-uplift and topographic evolution in the northern-central Apennines from linear inversion of the drainage system, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8880, https://doi.org/10.5194/egusphere-egu24-8880, 2024.

X2.78
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EGU24-10486
Maud J.M. Meijers, Tamás Mikes, Bora Rojay, Erkan Aydar, H. Evren Çubukçu, Thomas Wagner, and Andreas Mulch

In recent years, numerous studies focused on reconstructing the surface uplift history of the Central Anatolian Plateau (CAP) and the associated driving mechanisms such as slab breakoff, removal of lithospheric mantle, or crustal thickening (e.g. McPhee et al., 2021). The CAP forms the westward portion of the Turkish−Iranian plateau and has mostly been above sea level since ca. 41 Ma (Okay et al., 2020). Most of its present-day topography, featuring mean elevations of ca. 1.0-1.5 km, however, has been shaped since the Late Miocene (e.g. Meijers et al., 2018; Schildgen et al., 2012a,b). Perhaps the most spectacular discovery is the recognition of 2 km of surface uplift of a portion of the southern plateau margin, the Tauride Mountains, since ca. 0.5 Ma (Öğretmen et al., 2018).

Here, we provide stable isotope paleoaltimetry estimates for the Late Miocene for the southern CAP margin. The method is based on the inverse relationship between the oxygen isotopic composition (δ18O) of meteoric waters and elevation. We therefore contrast the δ18O values of age−equivalent low and (potential) high elevation soil carbonates (the δ−δ method; Mulch, 2016) from central Anatolia with published Anatolian and Aegean soil carbonate δ18O values (Böhme et al., 2017; Meijers et al., 2018; Quade et al., 1994). Our results reveal a low (ca. 0.5 km) orographic barrier between the Aegean and Mediterranean coastlines and central Anatolia at ca. 10 Ma, which increased to an elevation of ca. 1 km by ca. 8−6 Ma. This trend in increasing surface elevations during the Late Miocene is in agreement with stable isotope−derived paleoelevation estimates from Anatolian lacustrine carbonate records (Meijers et al., 2018). Given proposed post−0.5 Ma surface uplift of the southernmost plateau margin (Öğretmen et al., 2018), our results imply a phase of significant local subsidence bracketed between the latest Miocene and ca. 0.5 Ma. From the Pliocene onward, we also observe long-term trends toward higher δ18O values in soil carbonate data sets from the Aegean Sea and CAP region, which indicate increased aridification and possibly seasonality of rainfall in the region since the Pliocene. Additionally, our ‘modern’ soil carbonate records from central Anatolia underestimate the elevation of the modern Tauride orographic barrier (ca. 2.2 ± 0.5 km) at the southern plateau margin by ca. 0.5 to 1.0 km (non−linear vs. linear lapse rate, respectively). We attribute this underestimation to the mixing in of higher δ18O atmospheric moisture derived from the Black Sea compared to atmospheric moisture derived from the Mediterranean Sea during spring and early summer, a signal that is likely incorporated into soil carbonates that form at the onset of the dry summer season. Although atmospheric moisture derived from the Black Sea yields lower δ18O values than Mediterranean atmospheric moisture at sea level (Schemmel et al., 2013), the former undergoes less distillation across the significantly lower northern plateau margin (the Pontide Mountains). The presently observed mixing of Black Sea and Mediterranean Sea moisture sources might have also led to an underestimation of southern orographic barrier elevations in the geologic past.

How to cite: Meijers, M. J. M., Mikes, T., Rojay, B., Aydar, E., Çubukçu, H. E., Wagner, T., and Mulch, A.: Central Anatolian (Turkey) and Aegean (Greece) soil carbonate δ18O values reveal Late Miocene surface uplift of the southern plateau margin and post−Miocene aridification of the northeastern Mediterranean region, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10486, https://doi.org/10.5194/egusphere-egu24-10486, 2024.

X2.79
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EGU24-10633
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ECS
Detrital zircon dataset and it’s tectonic implications from the Qilian-Qaidam-Kunlun collage, northern Tibet
(withdrawn after no-show)
Weidong He, Yunpeng Dong, and Jiaopeng Sun
X2.80
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EGU24-9922
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ECS
Sedimentary and provenance constraints on Carboniferous multiple-stage paleogeographic and tectonic transitions in the East Kunlun-Qaidam
(withdrawn after no-show)
Yukun Qi and Jiaopeng Sun
X2.81
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EGU24-2360
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ECS
Foreland basin development in response to Proto-Tethyan Ocean closure, western North China Block
(withdrawn after no-show)
Jiaopeng Sun and Yunpeng Dong
X2.82
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EGU24-2357
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ECS
Detrital zircon characteristics of Paleoproterozoic-Ordovician in the Olongbuluke Terrane: implication for the affinity of Olongbuluke Terrane and the closure of the Proto-Tethys Ocean
(withdrawn after no-show)
Teng Wang, Yanan Zhou, and Hanning Wu
X2.83
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EGU24-4827
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ECS
Structural Deformation Responses In the Neoproterozoic Stratum to the Multiple Orogenesis Around the Southwestern Margin of the North China Craton
(withdrawn after no-show)
Yinglei Chang, Jinhai Luo, Zhuo Chen, and Guanxu Chen
X2.84
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EGU24-5345
Meso-Cenozoic lithospheric dynamic evolution in the Ordos Basin, China: insight from the study on geothermal and lithospheric thermal structure 
(withdrawn after no-show)
Kai Qi and Zhanli Ren
X2.85
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EGU24-6020
Low temperature thermochronological analysis and geological significance in the North of the Western Margin of the Ordos Basin: A case study of the Mo'er Gou section in the Wuhai region
(withdrawn after no-show)
Guangyuan Xing, Zhanli Ren, and Kai Qi
X2.86
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EGU24-9535
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ECS
Late Carboniferous to Permian paleoclimatic and tectono-sedimentary evolution of the central Ordos Basin, western North China Craton
(withdrawn)
Hua Tao and Junping Cui
X2.87
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EGU24-9089
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Ícaro Dias da Silva, Manuel Francisco Pereira, Emílio González-Clavijo, José Brandão Silva, and Lourenço Steel Hart

Mass transport deposits or olistostromes, carrying large-sized blocks or olistoliths, are related to active and passive margin tectonics. Information on how they are produced is critical to understanding the tectonically driven topographic dynamics in the source areas, and the tectonic evolution of sedimentary basins and their shoulders. The geological record of these mass transport deposits is commonly well preserved onshore, in orogenic regions where continental margins uplift was influenced by the gradual movement of continents.

The Iberian Massif is one of the World’s key areas for studying ancient orogenies, like the Late Paleozoic Variscan belt, to understanding the formation of olistostromes, and developing provenance studies on such complex tectonic fold and thrust belts. Structural relations between the basement and overlying Mississippian synorogenic marine basins were recently examined in the lower plate (Gondwana side) of the Variscan collisional orogeny in Iberia. The stratigraphy of these Variscan synorogenic basins is quite complex and includes: a) sedimentary melánges (e.g., related to submarine mudflows and turbidites) that carried or were formed by different-sized blocks of different age metamorphic, volcanic, siliciclastic and carbonated rocks derived from the nearby pre-Mississippian basement; b) partially or completely dismantled Devonian and/or Mississippian carbonate platforms; and c) syn-sedimentary bimodal calc-alkaline volcanism. Geochronology data show that Mississippian sedimentation and volcanism occurred simultaneously with regional high temperature-low pressure metamorphism, associated with the formation of gneiss domes, bounded by extensional shear zones and faults, during crustal thinning and plutons emplacement. Mapping of shear zones and faults on the Iberian Variscan basement provided crucial information for better comprehending Mississippian synorogenic basin architecture. Our study demonstrates that there is a spatial and temporal relationship between the generation of olistostromes (including large olistoliths) and the development of first-order extensional structures in the pre-Mississippian basement.

Given that the collision between Laurussia and Gondwana had already occurred, it seems that these Mississippian synorogenic basins were not formed in a foreland, backarc, or forearc setting related to the subduction of the Rheic oceanic lithosphere, and thus, other geodynamic hypotheses need to be set. Two tectonic models have been discussed to explain the occurrence of a significant thermal anomaly beneath the lower plate (Gondwana side) and the formation of the Mississippian synorogenic basins in Iberia: Model A) considers that the roll-back of the lower plate was responsible for the formation of an orogenic plateau, the lateral flow of partially molten orogenic roots, and peel-back tectonics, after the subduction of the Rheic Oceanic lithosphere under the upper plate (Laurussia side) and the subsequent continental collision. In this case, the Mississippian synorogenic basins would be of peel-back type; Model B) invokes the subduction of the Paleotethys oceanic lithosphere beneath the Variscan collisional orogen, and the Mississippian synorogenic basins would be of backarc type but developed later than the Rheic Ocean closure.

This work was supported by FCT I.P./MCTES (Portugal) through national funds (PIDDAC) – UIDB/50019/2020 (https://doi.org/10.54499/UIDB/50019/2020), UIDP/50019/2020 (https://doi.org/10.54499/UIDP/50019/2020), LA/P/0068/2020 (https://doi.org/10.54499/LA/P/0068/2020), DL57/2016/CP1479/CT0030 (https://doi.org/10.54499/DL57/2016/CP1479/CT0030), FCT/UIDB/ 04683/2020-ICT and by the Spanish Agency of Science and Technology MCIN/AEI/10.13039/501100011033 and TED2021- 130440B-I00

How to cite: Dias da Silva, Í., Pereira, M. F., González-Clavijo, E., Silva, J. B., and Steel Hart, L.: Variscan olistostromes and the geological history they tell… unraveling the tectonic evolution of the Pangea supercontinent , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9089, https://doi.org/10.5194/egusphere-egu24-9089, 2024.

X2.88
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EGU24-1362
Andrea Hampel, Andreas Wölfler, Reinhard Wolff, and Ralf Hetzel

In contrast to the mountainous topography and high relief of the eastern Tauern window, the adjacent Nock Mountains (Gurktal Alps, Austria) are characterized by hilly topography, lower relief and rounded summits with elevations of ca. 2000 m. Although the unusual landforms in the Nock Mountains have long been recognized (Hejl, 1997; Frisch et al., 2000, and references therein), little is known about rates of landscape evolution in this area, which was deglaciated ~15 ka ago (Wölfler et al., 2022). Here we present a new set of 16 catchment-wide erosion rates from the Nock Mountains derived from cosmogenic 10Be concentrations in stream-sediment samples. Samples from 10 major streams that drain the Nock Mountains toward the Mur-Mürz valley, the Katschberg-Lieser valley and the Drau valley range between ~130 and ~300 mm/ka. Smaller subcatchments with low relief located in the upper part of the larger catchments erode at lower rates between ~80 and ~160 mm/ka. A comparison between 10Be-derived erosion rates and exhumation rates obtained from low-temperature thermochronology and thermokinematic modelling reveals that short-term and long-term erosion rates are remarkably similar. In the central Nock Mountains, 10Be-derived erosion rates of 110-160 mm/ka are similar to the long-term exhumation rate of ~160 m/Ma since ~34 Ma (Wölfler et al., 2023). The southern Nock Mountains (Millstatt Complex) show higher short-term erosion rates of 170-300 mm/ka and also a higher long-term exhumation rate of ~270 m/Ma since 18 Ma (Wölfler et al., 2023). The similarity between short-term and long-term erosion rates suggests that the pace of erosion in the Nock Mountains did not change significantly during the late Cenozoic. A comparison of our data with 10Be erosion rates from the eastern Tauern Window (>500 m/Ma) and the Lavanttal Alps (<125 m/Ma) (Dixon et al., 2016; Delunel et al., 2021), which are located west and east of the Nock Mountains, respectively, reveals that erosion rates in the Eastern Alps decrease from west to east.

  • References
  • Delunel R, Schlunegger F, Valla PG, Dixon J, Glotzbach C et al. (2020) Earth-Sci. Rev. 211:103407.
  • Dixon JL, von Blanckenburg F, Stüwe K, Christl M (2016) Earth Surf. Dyn. 4:895909.
  • Frisch W, Székely B, Kuhlemann J, Dunkl I (2000) Zeitschr. f. Geomorph. 44:103–138.
  • Hejl E (1997) Tectonophysics 272:159–173.
  • Wölfler A, Hampel A, Dielforder A, Hetzel R, Glotzbach C (2022) J. Quat. Sci. 37:677-687.
  • Wölfler A, Wolff R, Hampel A, Hetzel R, Dunkl I (2023) Tectonics 42:e2022TC007698.

How to cite: Hampel, A., Wölfler, A., Wolff, R., and Hetzel, R.: 10Be-derived catchment-wide erosion rates from the Nock Mountains (Gurktal Alps, Austria): comparison with thermochronological data and implications for landscape evolution, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1362, https://doi.org/10.5194/egusphere-egu24-1362, 2024.

X2.89
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EGU24-11203
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ECS
Bastien Mathieux, Jérôme van der Woerd, François Chabaux, Philippe Steer, Julien Carcaillet, and Thierry Perrone

The Vosges massif is a mid-altitude mountain range located northeast of France. It extends latitudinally for 250 km north of the Alps and is characterized by topographic, geological and geomorphological north-south and east-west gradients. In the south, the exhumed Paleozoic basement culminates at about 1400 m asl while in the north, river valleys incise Mesozoic sandstones with summits ranging between 400 and 700 m asl. The relief is intricately linked to the Eocene-Oligocene formation of the Rhine graben and the Mio-Pliocene deformation of the Alpine foreland. The present-day slow deformation rates in the Rhine graben, coupled with the region’s moderate seismicity characterized predominantly by strike-slip mechanisms, raise questions about the current driving forces behind the Vosges’ topographic evolution.

The evolution of drainage divides provides a window into the complex interrelations among tectonic forces, surface erosion processes and climatic influences that contribute to shaping a mountain range. In this study, we combine morphometric and cosmogenic nuclides (10Be and 26Al) analyses to assess the migration of the Vosges’ main drainage divide. Gilbert’s metrics (elevation, relief and gradient) alongside χ-index reveal a strong eastward gradient across the divide suggesting a migration away from the Rhine graben margin. To provide a quantification of this migration, a dataset of in-situ cosmogenic nuclides whose concentrations are erosion-dependent has been measured in samples collected across various segments of the divide. Cosmogenic nuclide analysis reveals a robust set of 10Be/26Al ratios falling within the steady-state denudation curve and denudation rates, ranging from 30 to 90 mm/kyr in the south and 40 to 70 mm/kyr in the north. Notably, both regions display an eastward trend in denudation, corroborating the gradient observed in the morphometric analysis.  A geometric approach was used to translate cross-differences in denudation rates and topographic gradients into migration rates of the main drainage divide, showing a westward shift of 20-70 mm/kyr in the south and 3-30 mm/kyr in the north.

Expanding our analysis, we examined the correlation between the calculated denudation rates and the hilltop curvatures derived from high-resolution DEMs (1m). A relation appears in the south, whereas no relationship has been found in the north, suggesting additional complexities in controlling morphogenetic processes. This finding allows us to use hilltop curvature as a proxy for denudation rates, particularly within mono-lithologic soil-mantled basins along the southern Vosges drainage divide. These insights offer a valuable conceptual framework for constraining numerical simulations at the mountain range scale aimed at unravelling the external forces that shape the highest Vosges relief.

How to cite: Mathieux, B., van der Woerd, J., Chabaux, F., Steer, P., Carcaillet, J., and Perrone, T.: What controls the migration rate of divides? Insights from morphometry and 10Be and 26Al cosmogenic nuclides analysis applied to the Vosges massif, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11203, https://doi.org/10.5194/egusphere-egu24-11203, 2024.

X2.90
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EGU24-12254
Jérôme van der Woerd, Daniel S. Moreno Martin, Raphaël di Chiara Roupert, Bastien Mathieux, Thierry Perrone, Gilles Rixhon, Silke Merchel, Anne-Sophie Mériaux, and François Chabaux

Assessing the Quaternary topographic stability of western Europe middle mountains characterized by low tectonic activity remains challenging. We suggest to tackle this question in the Vosges – Upper Rhine Graben system where elevation reach up to 1400 m asl. This study is focused on the Strengbach catchment, that flows from the Vosges massif towards the Rhine graben, upstream of Ribeauvillé in the central Vosges. The catchment reaches 29 sq.km between 500 to 1200 m elevation. Morphometric analysis of the main trunk and tributaries is performed to constrain the areas of topographic disequilibrium along the valleys (knickpoints). 10Be cosmogenic isotope analysis in river sediments from various sites in the catchment is used to constrain the migration rates of these topographic instabilities at the millennial scale.

The morphometric analysis performed in the Strengbach catchment (catchment topography - χ-elevation profiles) provide evidence of relic topographic surfaces upstream of a 2 km-long convex knick-zone located at about 700 m. Below this zone, the catchment is deeply incised and ramified with knick-points in the tributaries at about 500 m. Above the knick-zone, fluvial incision is reduced with a high-standing knickpoint at about 950 m marking the upper section of the Strengbach stream. 10Be denudation rates points to relatively small variations along the main trunk upstream (36 ± 2 - 44 ± 3 mm/ka), while denudation rates derived from the tributaries range from 38 ± 2 mm/ka to 75 ± 5 mm/ka. We show that these variations are primarily controlled by topographic and lithologic factors, namely the presence of sandstones in the sub-catchments, characterized by higher erodibility than crystalline rocks. The 10Be cosmogenic isotope concentrations in sediments from both upstream and downstream of the knickpoints, and in the tributaries, constrain at first order the migration rate of the knickpoints along the river profile and the retreat rate of sandstone cliffs upstream some tributaries. Migration rates on the order of 100-200 m/Ma suggest that at the millennial scale, the topography is relatively stable. These data will be used to discuss the source of topographic disequilibrium present in the catchments.

How to cite: van der Woerd, J., Moreno Martin, D. S., di Chiara Roupert, R., Mathieux, B., Perrone, T., Rixhon, G., Merchel, S., Mériaux, A.-S., and Chabaux, F.: Relief stability of western Europe middle mountains from morphometry and 10Be denudation rates: the Strengbach catchment case in the central Vosges massif, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12254, https://doi.org/10.5194/egusphere-egu24-12254, 2024.