• Title of article

    Progressive evolution of a fault-related fold pair from growth strata geometries, Sant Llorenç de Morunys, SE Pyrenees

  • Author/Authors

    Ford، نويسنده , , Mary and Williams، نويسنده , , Edward A. and Artoni، نويسنده , , Andrea and Vergés، نويسنده , , Jaume and Hardy، نويسنده , , Stuart، نويسنده ,

  • Issue Information
    ماهنامه با شماره پیاپی سال 1997
  • Pages
    29
  • From page
    413
  • To page
    441
  • Abstract
    New structural-stratigraphical mapping constrains the three-dimensional kinematics and mechanisms of Eocene-Oligocene growth folding at Sant Llorenç de Morunys (NE Ebro basin, Spain). A 1 km wide sub-vertical panel of syntectonic alluvial gravels passes southwards via a highly asymmetrical growth fold-pair to shallowlydipping strata. The axial surface of the anticline comprises either continuous or en échelon segments while that of the syncline is concave and usually continuous. While converging upwards, the axial surfaces do not define growth triangles. Principal and subsidiary growth unconformities and thickness changes occur across both axial surfaces and the common limb. Dips within the common limb decrease up-stratigraphy and up-dip. Mesostructures indicate that internal deformation was ongoing during folding at all stratigraphical levels, and concentration of cleavage in the syncline indicates that this hinge was essentially fixed. Sequential restoration of three profiles shows that folds amplified principally by limb rotation but incorporated minor passive hinge migration. Particle movement vectors, generated by section restoration, are arcuate about a hinterland pinpoint. A new trishear model of fault propagation folding involving non-rigid limb rotation reproduces the rounded hinge forms, thickening geometries and limb dip variations observed. Simple kink band migration models (fixed axis and constant thickness theories) do not replicate these features.
  • Journal title
    Journal of Structural Geology
  • Serial Year
    1997
  • Journal title
    Journal of Structural Geology
  • Record number

    2223364