34 research outputs found

    Plio-Pleistocene transpressional reactivation of Paleozoic and Paleogene structures in the Rhine-Bresse transform zone (northern Switzerland and eastern France)

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    Pliocene to recent uplift and shortening in the southern Rhinegraben is documented by deformation of Pliocene fluvial gravels, deposited on a nearly planar surface, as well as by progressive deflection and capture of rivers. This deformation is suggested to result from thick-skinned tectonic movements as evidenced by observations on seismic records, which demonstrate a spatial coincidence between en-échelon anticlines at the surface and faults located in the crystalline basement. These findings contradict the often invoked thin-skinned tectonism in the recent tectonic history of the Rhinegraben. In particular the transfer zone between the Rhinegraben and the Bressegraben is very suitable for reactivation under the present day stress field. Thick-skinned reactivation of faults in the basement is also expressed by focal plane mechanisms of recent earthquakes showing strike-slip- rather than reverse faulting characteristics. This is of importance for the densely populated and industrialised southern Rhinegraben, previously affected by large earthquakes in historical times (e.g. Basel 1356

    A War of Area Attrition and Aimed Attack Properties of Optimal Strategies

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    Linking the northern Alps with their foreland: The latest exhumation history resolved by low-temperature thermochronology

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    The evolution of the Central Alpine deformation front (Subalpine Molasse) and its undeformed foreland is recently debated because of their role for deciphering the late orogenic evolution of the Alps. Its latest exhumation history is poorly understood due to the lack of late Miocene to Pliocene sediments. We constrain the late Miocene to Pliocene history of this transitional zone with apatite fission track and (U-Th)/He data. We used laser ablation inductively coupled mass spectrometry for apatite fission track dating and compare this method with previously published and unpublished external detector method fission track data. Two investigated sections across tectonic slices show that the Subalpine Molasse was tectonically active after the onset of folding of the Jura Mountains. This is much younger than hitherto assumed. Thrusting occurred at 10, 8, 6–5 Ma and potentially thereafter. This is contemporaneous with reported exhumation of the External Crystalline Massifs in the central Alps. The Jura Mountains and the Subalpine Molasse used the same detachments as the External Crystalline Massifs and are therefore kinematically coupled. Estimates on the amount of shortening and thrust displacement corroborate this idea. We argue that the tectonic signal is related to active shortening during the late stage of orogenesis

    Phenotip - a web-based instrument to help diagnosing fetal syndromes antenatally.

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    Prenatal ultrasound can often reliably distinguish fetal anatomic anomalies, particularly in the hands of an experienced ultrasonographer. Given the large number of existing syndromes and the significant overlap in prenatal findings, antenatal differentiation for syndrome diagnosis is difficult. We constructed a hierarchic tree of 1140 sonographic markers and submarkers, organized per organ system. Subsequently, a database of prenatally diagnosable syndromes was built. An internet-based search engine was then designed to search the syndrome database based on a single or multiple sonographic markers. Future developments will include a database with magnetic resonance imaging findings as well as further refinements in the search engine to allow prioritization based on incidence of syndromes and markers

    Do river profiles record along-stream variations of low uplift rate?

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    International audienceSpatial variations of gradients in landscapes may be used to identify and quantify recent deformation. The problem with doing this is to determine whether tectonic or climatic forcing is responsible for these variations, especially for low uplift rate environments (\ll1 mm yr-1) where climate changes may have erased tectonic features. We evaluate the respective contribution of low uplift rate (~0.1 mm yr-1) and Pleistocene climate oscillations on gradient variations of two comparable river profiles crossing different uplift zones in the southern Upper Rhine Graben. We compare the observed points of discontinuity in river profile (knickpoints) and convex portions (knickzones) with those predicted by a detachment-limited model that includes stochastic short-term and cyclic long-term variations in climate, a bedrock detachment threshold and rock uplift. The detachment-limited model is chosen as it predicts the development of persistent knickpoints. Differing values of the shear stress exponent, erosion threshold, climate variability and uplift pattern have been checked. Our modeling suggests that climate changes had no significant effects on profiles and that anomalies are more likely due to anticline growth. This surprising result arises from the combination of a very low regional uplift rate and the detachment-limited assumption. The detachment-limited model implies an upstream propagation of knickpoints and knickzones generated by uplift at the outlet during dry climate periods of low erosion. The greater the uplift rate, the larger the variations in river bed elevation. Thus, for high uplift rate, knickpoints and knickzones generated by climate oscillations are more likely to hide tectonic features. This result seems counterintuitive because it suggests that tectonic knickzones will be better preserved in low uplift rate environments, provided that the lithology is homogeneous

    Do river profiles record along-stream variations of low uplift rate?

    No full text
    International audienceSpatial variations of gradients in landscapes may be used to identify and quantify recent deformation. The problem with doing this is to determine whether tectonic or climatic forcing is responsible for these variations, especially for low uplift rate environments (\ll1 mm yr-1) where climate changes may have erased tectonic features. We evaluate the respective contribution of low uplift rate (~0.1 mm yr-1) and Pleistocene climate oscillations on gradient variations of two comparable river profiles crossing different uplift zones in the southern Upper Rhine Graben. We compare the observed points of discontinuity in river profile (knickpoints) and convex portions (knickzones) with those predicted by a detachment-limited model that includes stochastic short-term and cyclic long-term variations in climate, a bedrock detachment threshold and rock uplift. The detachment-limited model is chosen as it predicts the development of persistent knickpoints. Differing values of the shear stress exponent, erosion threshold, climate variability and uplift pattern have been checked. Our modeling suggests that climate changes had no significant effects on profiles and that anomalies are more likely due to anticline growth. This surprising result arises from the combination of a very low regional uplift rate and the detachment-limited assumption. The detachment-limited model implies an upstream propagation of knickpoints and knickzones generated by uplift at the outlet during dry climate periods of low erosion. The greater the uplift rate, the larger the variations in river bed elevation. Thus, for high uplift rate, knickpoints and knickzones generated by climate oscillations are more likely to hide tectonic features. This result seems counterintuitive because it suggests that tectonic knickzones will be better preserved in low uplift rate environments, provided that the lithology is homogeneous

    Do river profiles record along-stream variations of low uplift rate?

    No full text
    International audienceSpatial variations of gradients in landscapes may be used to identify and quantify recent deformation. The problem with doing this is to determine whether tectonic or climatic forcing is responsible for these variations, especially for low uplift rate environments (\ll1 mm yr-1) where climate changes may have erased tectonic features. We evaluate the respective contribution of low uplift rate (~0.1 mm yr-1) and Pleistocene climate oscillations on gradient variations of two comparable river profiles crossing different uplift zones in the southern Upper Rhine Graben. We compare the observed points of discontinuity in river profile (knickpoints) and convex portions (knickzones) with those predicted by a detachment-limited model that includes stochastic short-term and cyclic long-term variations in climate, a bedrock detachment threshold and rock uplift. The detachment-limited model is chosen as it predicts the development of persistent knickpoints. Differing values of the shear stress exponent, erosion threshold, climate variability and uplift pattern have been checked. Our modeling suggests that climate changes had no significant effects on profiles and that anomalies are more likely due to anticline growth. This surprising result arises from the combination of a very low regional uplift rate and the detachment-limited assumption. The detachment-limited model implies an upstream propagation of knickpoints and knickzones generated by uplift at the outlet during dry climate periods of low erosion. The greater the uplift rate, the larger the variations in river bed elevation. Thus, for high uplift rate, knickpoints and knickzones generated by climate oscillations are more likely to hide tectonic features. This result seems counterintuitive because it suggests that tectonic knickzones will be better preserved in low uplift rate environments, provided that the lithology is homogeneous

    THE ESA KYOTO-INV PROJECT

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    Switzerland participates to the Kyoto-Inv project, initiated in November 2002 in the framework of the Data User Programme of the ESA. The aim is to learn more about the potential of remote sensing techniques for greenhouse gas reporting under the Kyoto Protocol (KP) on land use, land-use change and forestry (LULUCF) activities. Three regions were chosen for which data were made available to serve as ground truth. The Prototype phase of the project has yielded promising results that may help for reporting under the KP on LULUCF activities. The reasons of the limitations of the project have been identified along with the necessary steps for improvements. We consider that, in the future, Switzerland may greatly benefit from operational services in this field. Our next request to the project is a full coverage of Switzerland using remote sensing
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