Kinematics of the central Hellenides

Abstract

Structural analysis along 24 cross sections crosscutting several windows in the central Hellenides provides the sense of nappe movements as well as the location of destroyed oceans lying between the Apulian and Eurasian continents from the Mesozoic. Orogeny took place in two phases: The first phase, “the Eo‐Hellenic” phase, was initiated by convergence of the Apulian and Pelagonian plates with west directed subduction and closure of the Pindos Ocean. Late Jurassic obduction of oceanic lithosphere over the western margin of the Pelagonian plate was followed by footwall imbrication, mylonites and sheath folds. During the late Cretaceous, uplift was associated with ductile normal faulting at depth and tectonic unroofing at shallow crustal levels. The second phase, “the Meso‐Hellenic” phase, comprised the closure of the Ambelakia Ocean at the eastern margin of the Pelagonian plate and continental subduction along the eastern margin of the Apulian plate. West directed subduction of the Ambelakia Ocean was associated with eastward directed ductile thrusting, folding and blueschist metamorphism. Blueschist formed within a simple duplex structure at depth and was subsequently overthrusted in the late Eocene onto the Olympos microcontinent, which acted as a major obstacle to the eastward directed nappe movements. Up to 150‐m‐thick cataclasites, kink folds and a spaced cleavage were formed during the late stage of the continental collision. “A subduction” along the eastern margin of the Apulian plate caused kink folding and reimbrication of the western parts of the Pelagonian basement. Since the Oligocene, the overthickened crust collapsed by means of low‐angle normal faults.

The Tectonostratigraphy of Cycladic Blueschist Unit on Sikinos and Sifnos: Implication for the Mesozoic Tectonic Setting

“…A third model suggest that the rift basin that hosted the protolith of CBU was situated between the north margin of Pelagonian and the Olympos-Almyropotamos continental fragment (Fig. 5b: III;Doutsos et al, 1993;Xypolias et al, 2003). Note that the latter fragment was separated from Pelagonian forming a narrow basin with an incipient oceanic crust.…”

“…1; inset) (Mountrakis, 1986;Doutsos et al, 1993). Within the Cycladic Massif, the CBU occupies an intermediate structural position (Fig.…”

Patterns of Ductile Deformation in Attico-Cycladic Massif

“…Contradicting kinematic evidence for ENE-(e.g. Barton 1976;Doutsos et al 1993) or WSW-(e.g. Schermer 1993) directed shearing has also been given for the tectonically equivalent nappe contact in the Mt.…”

“…ACM has an internal position within the Alpine orogenic belt of the Hellenides (Fig. 1 inset) and exposes a complex pile of high-pressure (HP) nappes/units, which are tectonically overlain by the Pelagonian zone, a belt of imbricated pre-Alpine crystalline rocks and Mesozoic marbles also belonging to the Internal Hellenides (Mountrakis, 1986;Doutsos et al, 1993;Anders et al, 2007).…”

The Emplacement of the Vermion Nappe in the Area of Kato Seli (Mt Vermion, Central Macedonia, Greece)

“…The geotectonic evolution of this part of the Hellenic orogen was studied by numerous researchers (Nance, 1981;Mountrakis, 1983;Vergely, 1984;Kilias and Mountrakis, 1989;Doutsos et al, 1993;Kilias et al, 2010;Avgerinas, 2014). The structures and kinematics of the deformational events reported in the above mentioned studies are sometimes controversial but generally two major orogenic phases are recognized.…”