Kinematics and strain partitioning in the southeast Hellenides (Greece)

Abstract

New kinematic and structural data from the tectonic windows of eastern Crete and the Dodecanese Islands combined with strain and quartz fabric analysis have enabled us to determine a detailed structural evolution of the region and to present a plate tectonic scenario for the southeast Hellenides.During the Early Mesozoic, the southeastern part of Apulia was separated from North Africa and the adjacent microplates by WNW-trending rift zones and NE-trending transfer faults. Displacement along the transfer faults has locally reoriented these rift zones into an ENE-WSW direction. Finite strain and quartz fabric asymmetry data indicate that in Late Cenozoic time, NNWdirected nappe movements caused a nearly coaxial deformation along the ENE-WSW trending rift segments and non coaxial top-to-the-southeast shearing along the WNW-trending rift segments, as well as along the pre-existing NE-trending transfer faults. Tectonic style along the margin varies in response to the obliquity of the principal shortening direction with respect to the margin. These variations could be due to the pre-convergence geometry of the southern margin of Eurasia and to local strain partitioning effects.Furthermore, a tectonic model is presented in which syncompressional uplift and vertical buoyancy of the subducted crustal slice caused the rapid exhumation of metamorphic units in the south Hellenides.

Geological and Magnetic Susceptibility Mapping of Mount Giouchta (Central Crete)

“…Additionally, it is noted that our data are also in agreement with kinematics and structural data from the tectonic windows of eastern Crete and Dodecanese Islands (Kokkalas and Doutsos, 2004).…”

Eocene to Early Oligocene turbidite sedimentation in the SE Aegean (Karpathos Island, SE Greece): stratigraphy, facies analysis, nannofossil study, and possible hydrocarbon potential

“…The pre-Neogene geological units of Karpathos are considered as a part of the External Hellenides (Christodoulou 1963;Davidson-Monett 1974;Aubouin et al 1976;Bonneau 1984;Fytrolakis 1989;Kokkalas & Doutsos 2004). The turbidite sediments rest on carbonate slope deposits of Cretaceous to Eocene age ( Figure 1).…”

“…These changes in paleocurrent directions (Figure 12) may also reflect the complexity of turbidite sedimentation in the area and the existence of more than one sediment source. If we take into account that the Dodecanese area received an average 25° counter-clockwise rotation since the Miocene (Kokkalas & Doutsos 2004;van Hinsbergen et al 2007), then the observed paleocurrent directions switch to a NE-SW general trend, which is possible to reflect the orientation of basin axis, in the case of axial currents' sedimentation. The hypothesis that submarine gravity flows of the Karpathos turbidite system were evolving parallel to the basin axis is strengthened by the cooccurrence of olistoliths and finegrained, probably distal deposits: as a turbidite system develops and progrades axially, olistostromes will probably become incorporated into upper-, middle-, and lower-fan components (Shanmugam & Moiola 1988).…”

“…In southeastern Greece, the Dodecanese Islands expose geological units that are of importance in attempting to understand the complex Mesozoic-Cenozoic evolution of this area (Harbury & Hall 1988;Garfunkel 2004;Kokkalas & Doutsos 2004;Franz et al 2005). The present study focuses on Paleogene deep-water clastic sediments deposited by subaqueous gravity flows (turbidites) that outcrop on the Dodecanese island of Karpathos.…”

“…Several authors worked on the geology of Karpathos (Christodoulou 1963;Davidson-Monett 1974;Aubouin et al 1976;Harbury 1986;Fytrolakis 1989;Kokkalas & Doutsos 2004), but the exposed turbidite deposits received little attention even though they cover a significant part of the island. The aim of this work is to provide a more detailed analysis of these deep-water clastic deposits based on sedimentological techniques (facies analysis, mapping, biostratigraphy, organic geochemistry), which may reveal information about depositional processes and subenvironments and also sedimentary basins' evolution in the area of the SE Aegean during the Tertiary.…”