Le contact Jura-Bresse dans la region de Lons-le-Saunier

Abstract

New information from borings shows that in the region to the west and north of the Lons-le-Saunier basin, France, the Jura border is thrust over the Tertiary of the Bresse region. The age of the movement is post-Pontian, and the amplitude over five kilometers at certain points. The movement occurred along gypsum and salt zones in the lower Keuper and Muschelkalk (Triassic) without disturbing the underlying Triassic, Permian, and Carboniferous beds.

Structure of the Tectonic Front of the Western Alps: Control of Fluid Pressure and Halite Occurrence on the Decollement Processes

“…Thrust tectonics involved the Savoy Molasse Basin and the inner Jura at least since the Burdigalian and syntectonic Burdigalian to Serravalian sedimentation occurred within the piggy-back basins developed between thrust anticlines of the Molasse Basin (Beck et al, 1998;Deville, Blanc, et al, 1994). It has been shown that the front of the Jura wedge is thrusted over Uppermost Miocene (Messinian) sediments for several kilometers in the Bresse Basin (Chauve et al, 1988;Michel et al, 1953). This timing of deformation is compatible with radiogenic U-Pb dating of syntectonic veins in the decollement zone (Looser et al, 2021).…”

“…The seismic data does not show any evidence for the involvement of the basement in the study area. The frontal part of the Jura Mountains is characterized by mixed compressional structures and passively transported extension structure inherited from the rifting phase during late Eocene-Oligocene-Aquitanian times (Michel et al, 1953;Philippe et al, 1996). In the central Jura (Figure 3a), two wells have demonstrated that, at depth, around the decollement level, the Upper Triassic is duplicated in the Valempoulières area which corresponds to a small gas field (Philippe et al, 1996;Figure 3b), whereas it is missing in the CHA-1 well (Figure 3c).…”

Map view retrodeformation of an arcuate fold‐and‐thrust belt: The Jura case

“…An estimate of displacement associated with the Jura Faisceaux plus the displacement associated with the Jura frontal thrust (Figure 4, green dashed line) in front of the northeastern zone defined above was then added to the displacements determined for the local reference frame. The overthrusting of the Jura Mesozoic cover on the Oligocene to early Pliocene deposits of the Bresse graben can be quantified based on well data which have found Cenozoic sediments beneath the Keuper detachment level [ Chauve et al , 1988b; Michel et al , 1953].…”

“…At that time the frontal Jura was thrust above the eastern border of the Bresse graben. The limits of the Jura frontal thrust on top of the Bresse Neogene fill are determined from well data and the thrust displacement reaches 6 km in places [ Chauve et al , 1988a; Michel et al , 1953].…”

Cenozoic Tectonic Deformation Along the Pontarlier Strike‐Slip Fault Zone (Swiss and French Jura Fold‐and‐Thrust Belt): Insights From Paleostress and Geomorphic Analyses

“…Michel et al. (1953) showed that the thrusting of the outermost Jura onto the Bresse Graben occurred around 5–7 Ma (Pontian age in Michel et al., 1953, now Messinian). More recently, the deformation period in the alpine foreland has been bracketed between 23 Ma (Chattian‐Aquitanian, Beck et al., 1998) for the oldest age and Plio‐Pleistocene to Recent for the the youngest ages (Giamboni et al., 2004; Madritsch, Preusser, et al., 2010; Mosar, 1999).…”