scholarly journals Late Pleistocene – Holocene surface processes and landscape evolution in the central Swiss Alps

Geomorphology ◽  
2017 ◽  
Vol 295 ◽  
pp. 306-322 ◽  
Author(s):  
Max Boxleitner ◽  
Alessandra Musso ◽  
Jarosław Waroszewski ◽  
Małgorzata Malkiewicz ◽  
Max Maisch ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Landscape Evolution ◽  
Swiss Alps ◽  
Surface Processes

scholarly journals Combined use of relative and absolute dating techniques for detecting signals of Alpine landscape evolution during the late Pleistocene and early Holocene

Geomorphology ◽  
2009 ◽  
Vol 112 (1-2) ◽  
pp. 48-66 ◽  
Author(s):  
Filippo Favilli ◽  
Markus Egli ◽  
Dagmar Brandova ◽  
Susan Ivy-Ochs ◽  
Peter Kubik ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Landscape Evolution ◽  
Early Holocene ◽  
Combined Use ◽  
Absolute Dating ◽  
Alpine Landscape

Inland dune field and deposits at Dviete: evidences of the late Pleistocene aeolian morphogenesis and landscape evolution during transition from glacial to post-glacial conditions in South-eastern Latvia

2020 ◽  
Author(s):  
Juris Soms ◽  
Zane Egle
Keyword(s):  
Late Pleistocene ◽  
Landscape Evolution ◽  
Last Deglaciation ◽  
Dune Field ◽  
Fine Grained ◽  
Aeolian Deposits ◽  
Aeolian Sediments ◽  
Aeolian Activity ◽  
Initial Evolution ◽  
Dammed Lake

<p>In the south-western part of Jersika Plain (SE Latvia), the late Pleistocene aeolian sediments form the inland dune field located at Dviete village. This dune field with surface >112 km<sup>2</sup> represents the evidence of aeolian activity and landscape evolution during the transition from glacial to post-glacial conditions in this region. The dunes have developed on the surface of glaciolacustrine plain, where subaqueous sedimentation in the Nīcgale ice-dammed lake took place during the retreat of glacier, the Pomeranian phase of the last glaciation.</p><p>Here, we focus on reconstructing paleoenvironmental conditions in this region, as inferred from landforms morphology, aeolian sand granulometry and geochemistry, and efficient wind directions derived from DEM. It will contribute to better understanding the processes of landscape evolution conditioned by last deglaciation in SE Latvia.</p><p>Results indicate that single parabolic dunes typically have U-shaped configuration in planar view. Aeolian landforms also link and override each other, presenting clustered groups. GIS analysis reveals that the dominating wind directions during the development of dunes would have been westerly to easterly. Previously published dates on OSL chronology for this dune field indicate the initial phase of aeolian activity at around 15.5 Ka and 14.5 Ka. Hence, when the studied landforms formed in presumably paraglacial landscape, the Scandinavian Ice Sheet (SIS) was still present, and most likely atmospheric circulation in this region was affected by anticyclone over the SIS.</p><p>The mean grain size <em>M<sub>z</sub></em> of the aeolian deposits forming inland dune field ranges between 143 μm and 256 μm. Hence aeolian landforms are composed mainly of fine-grained sands. It indicates the dominance of saltation and a balance between sand particles and comparatively low energy of local wind power during the aeolian processes. The sediments demonstrate well and moderately well sorting with σ values between 0.473 and 0.707 phi. Granulometry elucidates symmetrical distribution of particles of different fraction with small both negative and positive skewness <em>Sk</em> values ranging from -0.048 to 0.112 phi. For the values of kurtosis <em>K<sub>G</sub></em>, results showed that sand is mainly mesokurtic.</p><p>Geochemical analysis points out that elemental composition is rather typical for aeolian sediments, determined by the dominance of quartz and K-silicates. Among REE elements, only Y un Nb were identified in detectable concentrations. Similar geochemical signatures across the dune field suggest the provenance of sediments from one main source, possibly associated with glaciofluvial sediment transportation by extra-glacial waters draining from the already ice-free parts of adjoining uplands to the glacial lake.</p><p>As apparent from the limited number of paleosoils, aeolian deposition seems to nearly instantly follow the drainage of the Nīcgale ice-dammed lake. It is most likely that cold and dry climate in conjunction with low groundwater tables during the late Pleistocene – beginning of Holocene were among the main controlling factors which prevented development of vegetation cover in this region and delayed stabilisation of the dunes. In turn, it facilitates the action of wind over glaciolacustrine plain as the main driving process of aeolian morphogenesis during the initial evolution of metastable post-glacial landscape.</p>

Factors controlling the interaction between tectonics and surface processes in convergent orogens: insight from analogue and numerical models

2020 ◽  
Author(s):  
Riccardo Reitano ◽  
Claudio Faccenna ◽  
Francesca Funiciello ◽  
Fabio Corbi ◽  
Sean Willett
Keyword(s):  
Landscape Evolution ◽  
Numerical Models ◽  
Tectonic Setting ◽  
Laser Scanner ◽  
Sprinkler System ◽  
Surface Processes ◽  
Oblique View ◽  
Surface Uplift ◽  
Geomorphic Features ◽  
Set Up

<p>Convergent orogens are the best places on Earth for studying the interaction between surface processes and tectonics. They display the highest surface uplift rates and in turn are more likely affected by erosion. The balance between tectonics and erosion is responsible for many aspects in the evolution of a mountain belt. Despite the growth of analysis techniques, our understanding is still limited by the impossibility to observe these processes through their entire evolution. In particular, understanding how single parameters affect the system is necessary to unravel the nature of these multiple-interrelated processes.</p><p>Here we propose a new series of analogue models reproducing a simplified and scaled natural convergent orogenic system, to investigate the evolution of landscapes in which both tectonics and erosion/sedimentation are present. The growth of the orogenic wedge is driven by a rigid plate pushing the rear of the model. Deformed brittle granular material is a mixture of silica powder, glass microbeads and PVC powder. This mixture allows for the observation of both deforming structures and geomorphic features. Erosion is simulated by a water sprinkler system, providing a fine mist as precipitation which collects into simulated rivers, shaping the landscape. The model therefore allows observing the interaction between tectonics and surface processes. We analyze the model evolution monitoring oblique-view with cameras and top-view with a laser scanner. The latter is useful for measuring the mass balance between input fluxes (tectonics) and output fluxes (erosion) and in fulfilling a proper parametric study on the cause-effect relationship. The effect of different parameters on landscape evolution (e.g., precipitation rate, convergence velocity) is investigated systematically.</p><p>Our preliminary results analyze the relationship between single parameters and their effect on the models, allowing a proper definition of the role played in the landscape evolution. We also set up a benchmark with numerical models using DACI3ELVIS code in the same tectonic setting.</p>

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