Late Quaternary folding in the Jura Mountains: evidence from syn-erosional deformation of fluvial meanders

Abstract

Terra Nova, 00, 1–8, 2010 Abstract The present tectonic activity of the Jura fold‐and‐thrust belt is a matter of scientific debate. At its north‐western front, differentially uplifted palaeo‐meanders of the Doubs River record Late Quaternary growth of the Citadelle Anticline, associated with a minimum rock uplift of 13 m. Local rock uplift rates estimated from optical stimulated luminescence dating of oxbow lake deposits measure 0.17 ± 0.05 mm per annum. Reconstruction of the deformation history reveals that buckling took place simultaneously with focused Pleistocene river incision. The structural, geomorphic and temporal setting suggests that active deformation could possibly be sustained by incision‐related erosion. These observations shed new light on the modes of recent deformation in the Jura Mountains and on the present‐day dynamics of the Alpine orogenic front.

Deciphering neotectonics from river profile analysis in the karst Jura Mountains (northern Alpine foreland)

“…Folding and thrusting took place between about 14 and 3.3 Ma according to stratigraphic and paleontological evidences (Becker 2000;Schmid 2006, 2007 andreferences therein). However, geomorphological evidence suggest that more recent deformations (i.e., Pleistocene to Holocene) occured along the northernmost frontal thrusts of the Jura (Nivière and Winter 2000;Giamboni et al 2004b;Carretier et al 2006;Nivière et al 2006;Schmid 2006, 2007;Madritsch et al 2010b;Molliex et al 2011). These authors highlight a Plio-Pleistocene N-S horizontal shortening in the external part of the Jura with an average uplift velocity of *0.05 mm/year at the front.…”

“…During the northwestward propagation of the Jura deformation in the Plio-Pleistocene (Madritsch et al 2010b;Molliex et al 2011), the former southwestwardflowing network maintained its initial course, corresponding to the present-day downstream part of the Doubs River (from Montbéliard to its outlet, see Figs. 1,3c).…”

Possible Quaternary growth of a hidden anticline at the front of the Jura fold-and-thrust belt: geomorphological constraints from the Forêt de Chaux area, France

“…No evidence for active deformation has so far been recognized along the Routelle anticline. Further northeast, a late Quaternary activity has recently been demonstrated along the Citadelle anticline at Besançon [Madritsch et al, 2010b]. Like the Forêt de Chaux anticline, the Citadelle anticline also folds middle and upper Jurassic limestones and marls [Dreyfuss & Kuntz, 1967].…”

“…In the Doubs and Loue valleys, they are covered by Holocene alluvial deposits. This study aims at examining the so far poorly investigated Forêt de Chaux area for signs of recent tectonic deformation that have recently been reported from neighboring areas (Nivière & Winter 2000, Giamboni et al, 2004Madritsch et al, 2010b). Unfortunately, bad outcrop conditions hinder a field-based geological analysis of the Forêt de Chaux deposits.…”

“…The growth of the Citadelle anticline continued pro parte after the deposition of Forêt de Chaux-like fluviatile conglomerates now found at about 110 m above their original position inferred by extrapolation from an equilibrium profile between the Sundgau region of the southern Rhine graben and the Forêt de Chaux [Dreyfuss & Glangeaud, 1950;Campy, 1984;Madritsch et al, 2010b]. Uplifted Holocene alluvial deposits lying above the Citadelle anticline axis show that the growth of this anticline is still underway [Madritsch et al, 2010b]. However, given the distance and the lack of continuous exposures between the Forêt de Chaux anticline and the Citadelle anticline, it is hazardous to link the two anticlines.…”