Record of latest Barremian-Cenomanian environmental change in tectonically controlled depressions from the Jura-Burgundy threshold (Jura Mountains, eastern France and western Switzerland)
The area of the western Jura Mountains constitutes the former Jura-Burgundy threshold between the Tethys Ocean and the epicontinental Paris Basin Sea. During the Barremian, the area was covered by a shallow-water Urgonian carbonate platform. Tectonic processes influenced the architecture of the Urgonian platform and were notably responsible for the formation of fault-related depressions on top of the Urgonian series, which were subsequently transformed into incised valleys and then to marine depocenters. Their sedimentary infills are mostly represented by the Perte-du-Rhone Formation and record stepwise environmental change on the innermost platform, which was strongly influenced by the nearby landmass. From the latest Barremian onward, sedimentation progressively changed from: i) predominantly oncoidal and detrital charophyte-rich marly limestones; to ii) heterozoan marly limestones and marls; followed by iii) detrital sediments interspersed with numerous phosphatic conglomerates. These changes are linked with the onset of the latest Barremian Taxy Episode and with the following oceanic anoxic episodes (OAE's) la to d in the neighbouring basins. The sedimentary changes are associated with sedimentary sequences which formed during 2nd-order transgressions, and which express the effect of sea level fall followed by drowning events. The presence of a rich ammonite-fauna allowed a precise biostratigraphical dating of these events during the latest Barremian to Cenomanian time interval.
1.Univ Lausanne, Geopolis, Inst Earth Sci, CH-1015 Lausanne, Switzerland 2.Rue Ctr 81, CH-2405 La Chaux Du Milieu, Switzerland 3.1 Rue Pont, F-10450 Breviandes, France 4.Univ Bourgogne, CNRS, UMR 6282, Lab Biogeosci, 6 Blvd Gabriel, F-21000 Dijon, France 5.Univ Lausanne, Geopolis, Inst Earth Surface Dynam, CH-1015 Lausanne, Switzerland 6.Musee Cantonal Geol, Anthropole, CH-1015 Lausanne, Switzerland
Recommended Citation:
Pictet, A.,Mojon, P. -O.,Matrion, B.,et al. Record of latest Barremian-Cenomanian environmental change in tectonically controlled depressions from the Jura-Burgundy threshold (Jura Mountains, eastern France and western Switzerland)[J]. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,2019-01-01,514:627-654