scholarly journals The topographic signature of Quaternary tectonic uplift in the Ardennes massif (Western Europe)

2011 ◽  
Vol 15 (4) ◽  
pp. 1095-1107 ◽  
Author(s):  
N. Sougnez ◽  
V. Vanacker
Keyword(s):  
Western Europe ◽  
Morphological Characteristics ◽  
Channel Morphology ◽  
Tectonic Uplift ◽  
Transient Signal ◽  
River Channels ◽  
Fluvial System ◽  
Third Order ◽  
Erosion Processes ◽  
Uplift Rates

Abstract. Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 y. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This study aims to analyze the link between tectonic uplift rates and landscape morphology based on slope and channel morphometric indexes. To achieve this objective, we selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif (a Palaeozoic massif of NW Europe, principally located in Belgium) that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm yr−1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our analysis indicates that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronic, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.

scholarly journals Spatial variability in channel and slope morphology within the Ardennes Massif, and its link with tectonics

2010 ◽  
Vol 7 (5) ◽  
pp. 6981-7006 ◽  
Author(s):  
N. Sougnez ◽  
V. Vanacker
Keyword(s):  
Morphological Characteristics ◽  
Channel Morphology ◽  
Transient Signal ◽  
Tectonic Activity ◽  
River Channels ◽  
Fluvial System ◽  
Third Order ◽  
Erosion Processes ◽  
Wide Range ◽  
Uplift Rates

Abstract. Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 years. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This work focuses on a wide range of slope and river channel morphometric indices to study their behavior and strength in regions affected by low to moderate tectonic activity. We selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm year−1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our data indicate that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronous, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.

scholarly journals Recent changes in sediment redistribution in the upper parts of the fluvial system of European Russia: regional aspects

2015 ◽  
Vol 367 ◽  
pp. 333-339 ◽  
Author(s):  
O. P. Yermolaev ◽  
V. N. Golosov ◽  
M. V. Kumani ◽  
L. F. Litvin ◽  
I. I. Rysin ◽  
...  
Keyword(s):  
Arable Land ◽  
Russian Plain ◽  
Cultivated Land ◽  
River Channels ◽  
Fluvial System ◽  
Sediment Redistribution ◽  
Erosion Models ◽  
Gully Head ◽  
Major Reduction ◽  
Quantitative Assessments

Abstract. Quantitative assessments of soil loss from cultivated land and sediment redistribution along pathways from cultivated fields to river channels have been undertaken using a range of different methods and techniques, including erosion models, detailed studies of sediment redistribution in representative catchments, monitoring of gully head retreat and evaluation of sediment deposition in ponds and small reservoirs. Most of the sediment eroded from arable land is deposited between the lower portions of the cultivated slopes and the river channels. Less than 15% of the eroded sediment is delivered to the river channels. Sediment redistribution rates in the upper parts of the fluvial system have declined during the last 25 years in both the western and eastern parts of the Russian Plain, because of a major reduction of surface runoff during snowmelt and a reduction of the area of arable land in some parts of the study area.

scholarly journals Towards assessing the influence of sediment loading on Last Interglacial sea level

2019 ◽  
Vol 220 (1) ◽  
pp. 384-392
Author(s):  
T Pico
Keyword(s):  
Sea Level ◽  
Tectonic Uplift ◽  
Sediment Loading ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
Isostatic Adjustment ◽  
Uplift Rates ◽  
History Of ◽  
The Impact ◽  
The Last Glacial

SUMMARY Locally, the elevation of last interglacial (LIG; ∼122 ka) sea level markers is modulated by processes of vertical displacement, such as tectonic uplift or glacial isostatic adjustment, and these processes must be accounted for in deriving estimates of global ice volumes from geological sea level records. The impact of sediment loading on LIG sea level markers is generally not accounted for in these corrections, as it is assumed that the impact is negligible except in extremely high depositional settings, such as the world's largest river deltas. Here we perform a generalized test to assess the extent to which sediment loading may impact global variability in the present-day elevation of LIG sea level markers. We numerically simulate river sediment deposition using a diffusive model that incorporates a migrating shoreline to construct a global history of sedimentation over the last glacial cycle. We then calculate sea level changes due to this sediment loading using a gravitationally self-consistent model of glacial isostatic adjustment, and compare these predictions to a global compilation of LIG sea level data. We perform a statistical analysis, which accounts for spatial autocorrelation, across a global compilation of 1287 LIG sea level markers. Though limited by uncertainties in the LIG sea level database and the precise history of river deposition, this analysis suggests there is not a statistically significant global signal of sediment loading in LIG sea level markers. Nevertheless, at sites where LIG sea level markers have been measured, local sea level predicted using our simulated sediment loading history is perturbed up to 16 m. More generally, these predictions establish the relative sensitivity of different regions to sediment loading. Finally, we consider the implications of our results for estimates of tectonic uplift rates derived from LIG marine terraces; we predict that sediment loading causes 5–10 m of subsidence over the last glacial cycle at specific locations along active margin regions such as California and Barbados, where deriving long-term tectonic uplift rates from LIG shorelines is a common practice.

scholarly journals Distinct phases of eustatism and tectonics control the late Quaternary landscape evolution at the southern coastline of Crete

2016 ◽  
Author(s):  
Vasiliki Mouslopoulou ◽  
John Begg ◽  
Alexander Fülling ◽  
Daniel Moraetis ◽  
Panagiotis Partsinevelos ◽  
...  
Keyword(s):  
Landscape Evolution ◽  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Vertical Movement ◽  
Tectonic Uplift ◽  
Alluvial Fan ◽  
Contributing Factors ◽  
River Incision ◽  
Coastal Landscapes ◽  
Uplift Rates

Abstract. The extent to which climate, eustacy and tectonics interact to shape the late Quaternary landscape is poorly known. Alluvial fans often provide useful indexes that allow decoding the information recorded on complex coastal landscapes, such as those of Eastern Mediterranean. In this paper we analyse and date (using optically stimulated luminescence – OSL) a double alluvial-fan system in Crete, an island straddling the forearc of the Hellenic subduction margin, in order to constrain the timing of, and quantify the contributing factors to, its landscape evolution. The studied alluvial system is unique because each of its two juxtaposed fans records individual phases of alluvial and marine incision, providing, thus, unprecedented resolution in the formation and evolution of its landscape. Specifically, our analysis shows that the fan sequence at Domata developed during the last glaciation (Marine Isotope Stage 3; 57–29 kyr) due to five distinct stages of marine transgressions and regressions and associated river incision, as a response to climatic changes and tectonic uplift at rates of ~ 2.2 mm/yr. Comparison of our results with published tectonic uplift rates from Crete shows, however, that vertical movement on Crete was minimal during 20–50 kyr BP and mot uplift was accrued during the last 20 kyr. This implies that eustacy and tectonism impacted on the landscape at Domata over mainly distinct time-intervals (e.g. sequentially and not synchronously), forming and preserving the coastal landforms, respectively.

scholarly journals Numerical Investigation of Dissolved Oxygen Transportation through a Coupled SWE and Streeter–Phelps Model

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Jiaxin Wu ◽  
Xiaoxiang Yu
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Cross Sections ◽  
Morphological Changes ◽  
Shallow Water Equation ◽  
Morphological Characteristics ◽  
Coupled Model ◽  
River Channels ◽  
Cross Sectional ◽  
Important Indicator

Dissolved oxygen (DO) reflects the self-purification ability of a water body and is also an important indicator for quantifying the water quality. The morphological changes in the cross sections of river channels will affect the hydraulic conditions, and the distribution of pollutants and DO may also be affected, possibly resulting in local oxygen deficits and pollution. To effectively predict the water quality, a coupled model is introduced in this study. The shallow water equation (SWE) is adopted to calculate the hydrodynamic processes, and the modified Streeter–Phelps model is further coupled with the SWE model to evaluate the reaeration. By applying this model, mass transportation and reaeration in rivers are analyzed. The influences of the sudden cross-sectional changes in the river channel on the DO distribution and the reaeration ability are identified. The results reveal that a certain degree of expansion in the river is conducive to reaeration and can also accelerate the consumption of pollutants through the water body’s self-purification. DO transport in two real terrains, including a mountain basin and plain river, is extensively investigated, and the results indicate that the morphological characteristics in the mountain basin will cause the concentration distribution to form inside dead zones, while in the plain, the distribution will form a fan-shaped downstream zone.

Raised coastal terraces along the Ionian Sea coast of northern Calabria, Italy, suggest space and time variability of tectonic uplift rates

2009 ◽  
Vol 206 (1-2) ◽  
pp. 78-101 ◽  
Author(s):  
E. Santoro ◽  
M.E. Mazzella ◽  
L. Ferranti ◽  
A. Randisi ◽  
E. Napolitano ◽  
...  
Keyword(s):  
Tectonic Uplift ◽  
Time Variability ◽  
Ionian Sea ◽  
Space And Time ◽  
Uplift Rates ◽  
Sea Coast

Cladonia rei is a chemotype and synonym of Cladonia subulata

2006 ◽  
Vol 39 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Leo SPIER ◽  
André APTROOT
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Morphological Study ◽  
Western Europe ◽  
Morphological Characteristics ◽  
Long Wave ◽  
Layer Chromatography ◽  
Detailed Chemical ◽  
West European

A detailed chemical and morphological study has been carried out on West European specimens of Cladonia subulata (L.) F. H. Wigg. and C. rei Schaer. Using thin-layer chromatography (TLC), three different chemotypes were found, which did not show any correlation with distribution, substratum, habitat or any of the morphological characteristics mentioned in recent floras. Moreover, the application of UV (long-wave) proved to be unreliable for detecting homosekikaic acid and thus for distinguishing the two species. It appears that only one species, with three chemotypes, exists in Western Europe. Cladonia subulata is therefore another of the more than ten Cladonia species reported so far that can contain either homosekikaic and/or fumarprotocetraric acid.

Frequency and intensity of high-altitude floods over the last 3.5 ka in northwestern French Alps (Lake Anterne)

2012 ◽  
Vol 77 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Charline Giguet-Covex ◽  
Fabien Arnaud ◽  
Dirk Enters ◽  
Jérôme Poulenard ◽  
Laurent Millet ◽  
...  
Keyword(s):  
Iron Age ◽  
Western Europe ◽  
Ice Age ◽  
Flood Hazards ◽  
Mountain Areas ◽  
Erosion Processes ◽  
Highly Sensitive ◽  
Geochemical Analyses ◽  
Mild Temperature ◽  
Precipitation Events

In central Western Europe, several studies have shown that colder Holocene periods, such as the Little Ice Age, also correspond to wet periods. However, in mountain areas which are highly sensitive to erosion processes and where precipitation events can be localized, past evolution of hydrological activity might be more complicated. To assess these past hydrological changes, a paleolimnological approach was applied on a 13.4-m-long sediment core taken in alpine Lake Anterne (2063 m asl) and representing the last 3.5 ka. Lake sedimentation is mainly composed of flood deposits triggered by precipitation events. Sedimentological and geochemical analyses show that floods were more frequent during cold periods while high-intensity flood events occurred preferentially during warmer periods. In mild temperature conditions, both flood patterns are present. This underlines the complex relationship between flood hazards and climatic change in mountain areas. During the warmer and/or dryer times of the end of Iron Age and the Roman Period, both the frequency and intensity of floods increased. This is interpreted as an effect of human-induced clearing for grazing activities and reveals that anthropogenic interferences must be taken into account when reconstructing climatic signals from natural archives.

scholarly journals Channel Migration of the Meandering River Fan: A Case Study of the Okavango Delta

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3319
Author(s):  
Xue Yan ◽  
Jinliang Zhang ◽  
Yang Li ◽  
Long Sun
Keyword(s):  
Sedimentary Facies ◽  
Google Earth ◽  
Okavango Delta ◽  
River Channels ◽  
Fluvial System ◽  
Channel Migration ◽  
Sinuosity Index ◽  
Meandering River ◽  
The Difference ◽  
River Migration

Okavango delta is a typical distributive fluvial system, which is composed of a series of sand island-river-swamp networks. River migration in the Okavango delta is analyzed by using satellite images from Google Earth and Alaska Satellite Facility (ASF). Four configuration characterization parameters are selected to depict and measure the meandering river. These four parameters are sinuosity index (S), curvature (C), the difference of along-current deflection angle (Δθ) and expansion coefficient (Km). In the fan, the channel migration is mainly asymmetric. According to geomorphic elements and associated features, Okavango Delta can be subdivided into three zones: axial zone, median zone and distal zone. Under the influence of slope, climate and vegetation, different migration modes are developed in different zones. As the river moves downstream, the sinuosity index of the river on the Okavango Delta decreases downstream. Based on the characteristics of different zones, the sedimentary facies model of a single source distributive fluvial system of a meandering river is proposed. The models of channel migration and sedimentary facies have wide application. This research will not only provide a basis for the prediction of future river channels but will also provide important theoretical guidance for the study of the sedimentary morphology of underground reservoirs.

FLUVIAL ARCHITECTURE AND THE TECTONIC CONTROL ON DEPOSITION OF ONSHORE EUMERALLA FORMATION, OTWAY RANGES, VICTORIA: IMPLICATIONS FOR EXPLORATION IN THE EARLY CRETACEOUS OTWAY BASIN

2003 ◽  
Vol 43 (1) ◽  
pp. 99 ◽  
Author(s):  
C.A. Noll ◽  
M. Hall
Keyword(s):  
Hanging Wall ◽  
Normal Faults ◽  
River Channels ◽  
Fluvial System ◽  
Reservoir Properties ◽  
Local Study ◽  
Architectural Analysis ◽  
Drainage Patterns ◽  
Potential Source Rock ◽  
Fluvial Architecture

Spectacular outcrops of the terrestrial Aptian-Albian Eumeralla Formation are exposed in the Skenes Creek– Wongarra region, located on the eastern margin of the Otway Ranges, Victoria. The succession comprises mudstone-dominated floodplain and lacustrine successions and fluvially-derived sandstones. Lithofacies observed in the study area comprise intraformational and exotically derived conglomerate, massive and planar laminated sandstone, trough and tabular cross-bedded sandstone, ripple laminated sandstone, interbedded sandstone and mudstone, massive to laminated mudstone and thin coal seams. Architectural analysis of the fluvial system reveals these lithofacies are arranged into architectural elements that include channel elements, sandy bedforms, downstream and lateral accretion elements, laminated sand sheets and overbank fines elements.The fluvial system is characterised by low-sinuousity, braided river channels with high width to depth ratios. Palaeocurrent data indicates that the generally westward palaeoflow is interpreted to have been diverted into local axial-through drainage patterns by active northeast trending normal faults. One of these, the Skenes Creek Fault, is also likely to have structurally isolated floodplain and lacustrine successions from the main channel belt, leading to the deposition of an anomalously thick coal measure sequence in the hanging wall of the fault. The local study therefore provides insight into regional lithofacies and potential source rock distributions, and the associated tectonostratigraphic evolution of the Eumeralla Formation in the eastern Otway Basin. While the nature of the Eumeralla Formation sandstone does not lend itself to good reservoir properties, the geometry and internal structure of the sands provide an excellent model for other fluvial sandstone reservoir reconstructions.

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