Major palaeohydrographic changes in Alpine foreland during the Pliocene ‐ Pleistocene

Abstract

Bonvalot, J. 1996 (June): Major palaeohydrographic changes in Alpine foreland during the Pliocene-Pleistocene. Boreas, VoI. 25, pp. 131 -143. Oslo. ISSN 0300-9483.The changing palaeogeographical pattern of Alpine deposits across the European forelands can be traced by identifying mineral assemblages and establishing the chronology of Pliocene-Pleistocene deposits in Alpine foreland. In the late Miocene, the upper courses of the Rhine and the Aar flowed east from the Swiss molasse plain towards the Danube. In the early Pliocene (Brunssumian, 5-3.2 Ma), these same rivers headed northwards towards the Rhine Graben of Alsace. In the early Reuverian, these streams were captured south of the Rhine Graben by the Doubs. They ceased their northward flow and headed west to feed the Bresse Graben. This phase is dated to the Lower and Middle Reuverian (3.2-2.6 Ma). From the Upper Reuverian (2.6 Ma) to the present day, the Rhine has adapted approximately its present course towards the North Sea, south to north along the Rhine Graben and across the Rhine Schist Massif to feed the Dutch Grabens. This changing pattern of capture and alteration of the hydrographic system of the upper reaches of the Rhine and the Aar can be explained by local tectonic movements.

High magnitude and rapid incision from river capture: Rhine River, Switzerland

“…Around~4.2 Ma, drainage reorganization diverted the Aare-Danube toward the paleo-Doubs River (and eventually into the Mediterranean Sea) forming the Aare-Doubs system ( Figure 2b) [Petit et al, 1996]. At~2.9 Ma, the Aare-Doubs was captured by the Rhine River resulting in an early Aare-Rhine system draining through the Upper Rhine Graben and eventually into the North Sea (Figures 1 and 2c) [Petit et al, 1996;Hagedorn and Boenigk, 2008]. Additionally, a portion of the Alpine Rhine remained isolated from the Aare-Doubs system and continued flowing to the Danube until the late to middle Quaternary (~1.7-0.8 Ma; Figures 1 and 2d) [Villinger, 1998;Ziegler and Fraefel, 2009;Muttoni et al, 2003].…”

“…We use their reconstructions to focus on major reorganization events within the Aare-Rhine system since the early Pliocene (Figure 1). Sedimentological evidence suggests that the paleo-Aare flowed toward the Danube (and eventually into the Black Sea) forming the AareDanube system prior to~4.2 Ma (Figure 2a) [Manz, 1934;Liniger, 1966;Villinger, 1986;Hofmann, 1996;Petit et al, 1996]. Around~4.2 Ma, drainage reorganization diverted the Aare-Danube toward the paleo-Doubs River (and eventually into the Mediterranean Sea) forming the Aare-Doubs system ( Figure 2b) [Petit et al, 1996].…”

“…Sedimentological evidence suggests that the paleo-Aare flowed toward the Danube (and eventually into the Black Sea) forming the AareDanube system prior to~4.2 Ma (Figure 2a) [Manz, 1934;Liniger, 1966;Villinger, 1986;Hofmann, 1996;Petit et al, 1996]. Around~4.2 Ma, drainage reorganization diverted the Aare-Danube toward the paleo-Doubs River (and eventually into the Mediterranean Sea) forming the Aare-Doubs system ( Figure 2b) [Petit et al, 1996]. At~2.9 Ma, the Aare-Doubs was captured by the Rhine River resulting in an early Aare-Rhine system draining through the Upper Rhine Graben and eventually into the North Sea (Figures 1 and 2c) [Petit et al, 1996;Hagedorn and Boenigk, 2008].…”

“…[4] Here we use a simple river incision model to quantify the possible and plausible river responses to the magnitude of drainage area changes consistent with the reorganization of the Rhine River in central Europe, perhaps the best documented case of drainage reorganization in the recent geologic past (Figure 1a) [Petit et al, 1996;Berger et al, 2005;Ziegler and Fraefel, 2009;Schlunegger and Mosar, 2011]. Fluvial gravels along the uppermost Danube indicate that prior to~4.2 Ma, a paleo-river flowed to the northeast from Waldshut to Blumberg (Figure 1b).…”

“…[3] Large drainage basin reorganization events are proposed to have occurred in a number of river basins around the world including the Colorado [Lucchitta, 1979], Rhine [Petit et al, 1996;Ziegler and Fraefel, 2009], Snake [Beranek et al, 2006], Yellow [Craddock et al, 2010], Yangtze [Clark et al, 2004], Indus [Clift and Blusztajn, 2005], Ohio [Gray, 1991], and Zambezi [Thomas and Shaw, 1988] Rivers. Understanding the impact of drainage reorganization on erosion rates and processes is fundamental to understanding the controls on catchment denudation and landscape evolution in these regions.…”