Large‐scale relief development related to Quaternary tectonic uplift of a Proterozoic‐Paleozoic basement: The Armorican Massif, NW France

Abstract

Abstract. The topography of basements located in intraplate domains has often been interpreted in terms of planation theory by examining the remnants of paleosurfaces. In this paper, we address the significance of the present-day drainage networks that erode such topographies by looking at the relief development on the Armorican Massif basement (northwestern France). Using digital elevation model (DEM) analysis, the topography of this massif is characterized by large-scale (-250 km) relief variations that define high elevation domains (I-tEDs). These domains control the pattern of drainage networks by setting the location of the main drainage divides and the polarity of the regional slopes. Large-scale relief is strongly associated with the existence of scarps along inherited fault zones, suggesting that relief development is mainly controlled by tectonics through fault reactivation. A surface evolution study shows that drainage networks developed during the Quaternary, which corresponds to the timing of the tectonic activity which also led to relief development. The study of Quaternary fluvial erosion through a new method for measuring incision shows that the drainage basins of the I-tEDs record greater amounts of base level fall during Quaternary times. This implies that differential uplift is responsible for the large-scale relief development of the Armorican Massif during the Quaternary. Our study suggests that as seen in active settings, the topography of basements corresponds to a dynamic signal between tectonics and erosional processes which can be used, for example, in the study of intraplate deformation.

TOPO-EUROPE: The geoscience of coupled deep Earth-surface processes

“…Geomorphologic studies indicate that this uplift pattern controls the magnitude of fluvial incision, the location of drainage divides and repeated river captures. Moreover, Pleistocene deposits are locally folded and faulted (Bonnet et al, 1998;Bonnet et al, 2000;Brault et al, 2001). As the spatial pattern and timing of uplift inferred from river incision cannot be explained by glacio-eustatic sea level fluctuations, the underlying vertical crustal motions must be attributed to deformation of the lithosphere under the present-day NW-SE directed compressional stress field .…”

Detection and analysis of morphotectonic features utilizing satellite remote sensing and GIS: An example in SW Jordan

“…Analysing such valley cross-sectional shapes is helpful to explore the influence of tectonic forces on valley morphology (Prasicek et al, 2015). The changes in depth of the valley bottom generally imply changing erosion rates along the stream, possibly resulting from tectonic uplift or subsidence (Bonnet et al, 2000).…”

Spectral analysis of the gravity and elevation along the western Africa–Eurasia plate tectonic limit: Continental versus oceanic lithospheric folding signals

“…Cloetingh et al, 1999Cloetingh et al, , 2002Stephenson and Cloetingh, 1991;Lambeck, 1983;McAdoo and Sandwell, 1985;Ziegler et al, 1995;Bonnet et al, 2000;Gerbault, 2000;Krishna et al, 2001) to put forward a process of deformation through buckling of the entire lithosphere (known as lithospheric folding). These have been found within intraplate settings, both in continental lithosphere (Brittany, Iberia, Artic Canada, Central Asia, Alps, and Pannonian Basin) and in oceanic lithosphere (Indian Ocean).…”