[1] Clastic dikes may form by simultaneous fracture propagation in rocks and injection of clastic material into the fractures resulting from strong seismic shaking. We studied the mechanisms of clastic-dike formation within the seismically active Dead Sea basin, where hundreds of clastic dikes cross-cut the soft rock of the late Pleistocene lacustrine Lisan Formation. We analyzed the anisotropy of magnetic susceptibility (AMS) of dikes with known formation mechanisms and defined the characteristic AMS signatures, mainly of dikes developed by injection process. Most of the dikes were emplaced due to fluidization of clay-rich sediment and are characterized by triaxial AMS ellipsoids. The dominant triaxial AMS ellipsoids along the dike widths suggest that the fluidization mechanism of clay-rich sediment is different from the known liquefaction process of sand. The AMS analysis supported by field evidence indicates that the injection of clay-rich sediment is characterized by two main regimes: (1) Vertical flow characterized by subvertical V 2 axes and subhorizontal V 1 and V 3 axes. The V 2 axes may indicate the flow directions during fast flow. (2) Horizontal slow flow characterized by subvertical V 3 axes and subhorizontal V 1 and V 2 axes. A streaked AMS pattern mainly composed of V 2 and V 3 axes represents a turbulent flow that generated local eddies simultaneously with the clastic transport. The AMS parameters along the dikes and possible grain imbrications along dike walls support organization of grains under high strain rates. This application of the AMS method provides a petrofabric tool for identifying seismites and inferring their flow kinematics in complex geologic areas.

Sedimentary facies controls structural style up through multiple slump sheets and MTD's Detrital-dominated slump 4 undergoes folding Aragonite-dominated slump 5 undergoes thrusting 03/03/2016 Alsop et al. Styles of deformation in seismogenic slumps 1

Clastic dikes form either by passive deposition of clastic material into preexisting fissures or by fracturing and injection of clastic material during seismic shaking or passive overpressure. Because of their similar final geometry, the origin of clastic dikes is commonly ambiguous. We studied the mechanisms of clastic dike formation within the seismically active Dead Sea basin, where hundreds of clastic dikes crosscut soft rock of the late Pleistocene lacustrine Lisan Formation. We analyzed the anisotropy of magnetic susceptibility (AMS) of clastic dikes of known origin and defined characteristic AMS signatures of depositional or injection filling. We discovered that passively filled dikes, which contain brownish silt resembling local surface sediments, are characterized by an oblate AMS ellipsoid and vertical minimum susceptibility axis V 3 . Dikes that contain green clayey sediment connected to a mineralogically identical detrital layer of the Lisan Formation are characterized by a triaxial AMS ellipsoid, well grouped subhorizontal and parallel to the dike walls' maximum susceptibility axis V 1 , and subvertical intermediate susceptibility axis V 2 . Field evidence and AMS analysis indicate that most of these dikes were emplaced by injection inferred to be due to seismically triggered fluidization. This novel application of the AMS provides a petrofabric tool for distinguishing passively filled dikes from injection dikes and, where appropriate, for identifying the latter as seismites.

Thrust ramps within MTDs initiate within competent horizons in the hangingwall of the underlying detachment.Within MTDs, the spacing of thrust ramps and thickness of the thrust sequence display a ~ 5:1 ratio.Thrust systems within MTDs display greater variations in hangingwall and footwall cut-offs (or stretch) than in lithified rocks.Thrust systems within MTDs broadly 'balance', although heterogeneous lateral compaction increases by ~10% towards the surface.Critical taper angle in MTDs may be an order of magnitude less than in accretionary complexes and lithified rocks.