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

Abstract

Abstract. Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 10 3 to 10 5 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 km 2 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.

Earth Surface Processes and Environmental Changes in East Asia

“…In contrast, equilibrium (graded) rivers in natural fields tend to conserve concave-up profiles (approximated by the exponential function) (Zaprowski et al 2005;Sougnez and Vanacker 2011). Actually, rivers with concave-up longitudinal profiles are generally located in zones with low uplift rates (Sougnez and Vanacker 2011). 16.9).…”

“…16.9). In contrast, equilibrium (graded) rivers in natural fields tend to conserve concave-up profiles (approximated by the exponential function) (Zaprowski et al 2005;Sougnez and Vanacker 2011). 16.6) and they had relatively large water discharges that caused fast downward erosion in comparison with uplift.…”

Adjustment processes of mountainous rivers affected by tilting uplift: Laboratory experiments and a case study of Yakushima Island, Japan

“…There is another method for the estimation of uplift rate, which is based on the stream power model along with the assumption of a uniform uplift rate and a tectonic steady state (e.g. Sougnez & Vanacker, ). The stream power model expresses the incision rate ( E ) as a product of two power functions of the drainage area (upstream contributing area: A ) and the riverbed slope ( S ), where the drainage area is a surrogate of water discharge, thus E = k A m S n , where k is a coefficient, and m and n are power exponents.…”

Structural control of fluvial drainage in the western domain of the Cape Fold Belt, South Africa

“…The former is related to fault line scarps and juxtaposition of rocks of contrasting erosion resistance (Moon, 1988), thus enhancing differential erosion and the proliferation of knick points on the longitudinal profile of the drainage network. Demoulin (1998), Tebbens et al (2000) and Sougnez and Vanacker (2011) discussed the interactions between tectonics and longitudinal river profile development. On the other hand, horizontal crustal displacement leads to stream course off-setting, especially where there are active strike-slip faults (Burrato et al, 2003;Raj, 2007).…”