Abstract Microstructural, petrofabric, strain and vorticity data from quartz-rich tectonites were used to investigate the kinematics of rock flow in the Evia and Ochi ductile thrust zones, formed during exhumation of the high-pressure nappes of the Attico-Cycladic Massif. The Evia thrust zone defines the base of the Styra nappe while the Ochi thrust zone defines the contact between the Styra and the overlying Ochi nappe. A dominant top-to-the-ENE sense of shearing along both thrust zones is indicated by several shear sense criteria. Deformation in the structurally deeper Evia thrust zone occurred under approximately plane strain conditions and was characterized by a R XZ strain ratio varying from 3 to 6. The vorticity profile above the thrust plane shows a slight down-section increase in the kinematic vorticity number (W m ) from 0.8 to 0.9, as well as the presence of local thin domains with a higher pure shear component of deformation. In the overlying Ochi thrust zone, a downward increase in W m values from 0.6 to 0.9 is detected both above and below the thrust plane. Here, rocks have been deformed in the general constrictional field with R XZ values ranging between 5 and 8. A transport-parallel elongation of 30–90% and 50–160% has been estimated for the Evia and Ochi thrust zones, respectively, implying that ENE-directed extrusive flow controlled the formation, stacking and exhumation of the Styra and Ochi nappes.

Abstract Petrofabric, finite strain and kinematic vorticity data were used to investigate the heterogeneous nature of ductile deformation along a 1.5–2 km thick extruding shear zone in the south Peloponnese, that formed under blueschist-facies conditions. Asymmetric quartz c-axis fabrics confirm westward thrust movements on an east-dipping shear zone and provide evidence for localized top-down-to-the-east shear sense at the front of the zone. Strain ratio (R xz ) is nearly constant ( c. 3.0–4.0) along the upper structural levels of the zone but increases systematically from the middle to the bottom, approaching a value of c. 9.5 in the frontal parts, close to the basal thrust, and a value of c. 7.0 in the inner parts. The distribution of kinematic vorticity number depicts a simple-shear-dominated domain in the lower half of the shear zone and shows that the pure shear component always increases upwards in the zone, becoming dominant at the top of the inner parts of the zone. Integration of strain and vorticity data yields a shear-parallel elongation of c. 60–90% at the top and c. 40–60% at the bottom of the zone, revealing that both upper and lower surfaces of the extruding slices were ‘stretching faults’. Minimum total displacements of 25 and 41 km and slip rates of 6.5 and 10 mm/year were estimated for the basal and roof faults, respectively.

Abstract In the context of the External Hellenides, ‘pro’-lithosphere, corresponding to the Apulian microcontinent, converges on ‘retro’-lithosphere, corresponding to the Pelagonian microcontinent. Structural and stratigraphic data in the External Hellenides suggest that the convergence at this margin is fairly well described by the conceptual doubly vergent accretionary wedge model. This new orogenic model for the External Hellenides differs from the classical west-verging assumption and emphasizes that the retro-mass flux is critical for the pro-mass flux. Our model is primarily 2D, and is described in terms of three system components: an accretionary wedge (or pro-wedge), an uplifted plug and a retro-wedge. Three ‘isopic’ zones (Pindos, Gavrovo-Tripolitsa and Ionian) are included in the pro-wedge. The uplifted plug in the north (Epirus area) includes the Pindos ocean ophiolitic rocks and the Pindos zone, the Parnassos zone in central Greece, and the HP belt of the External Hellenides in the Peloponnese. The retro-wedge includes the Mesohellenic Trough in the north and the Argos plain in the south.