Tectonic evolution and stress field of the Kymi-Aliveri basin, Evia island, Greece

Κοκκάλας, Σ.

doi:10.12681/bgsg.17019

Cited by 7 publications

(20 citation statements)

References 12 publications

(13 reference statements)

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“…Its PlioPleistocene extensional deformation better resembles that of Region II, where mesoscopic WNW-trending faults were formed under tension in a northeast direction, while the ENEtrending faults were reactivated, displaying oblique normal motion along them (Fig. 4, stress net II E ; Kokkalas, 2001). In contrast, the Miocene evolution of the Kymi basin better resembles that of the molassic basins of the central part of the Hellenic arc (Region IV), and therefore it will also be discussed in the section on that region.…”

Section: Extensional Structuresmentioning

confidence: 98%

“…This orocline contributed to the arcuate geometry of the External Hellenides. At least part of the rotational deformation can be associated with contractional deformation in the middle Miocene (Boronkay and Doutsos, 1994;Kokkalas andDoutsos, 2001, 2004;van Hinsbergen et al, 2005).…”

Section: General Tectonic Frameworkmentioning

confidence: 99%

“…Backthrusting and/or transpression during a middle Miocene late orogenic stage completed this process (Doutsos et al, 1993, for Thessaly;Koukouvelas, 2001, for the Peloponnesus;Xypolias et al, 2003, for Evia;Kokkalas and2004, for Crete).…”

Section: Structural Region Iv: Central Part Of the Hellenic Arcmentioning

confidence: 99%

“…8A, lithostratigraphic section). The western margin of the basin is marked by a NNE-trending arcuate right lateral transpressional fault, the Kymi fault (Kokkalas, 2001), resulting in a vertical structural relief of more than 1300 m (Fig. 8A).…”

Section: Contractional Structuresmentioning

confidence: 99%

“…8A, Kymi basin, stress net IV K ). During this period (the upper Miocene and after the Oxylithos intrusion at 13 Ma), the Kymi basin was strongly modified by an orthogonal system of ENE-and NNWtrending normal faults (Kokkalas, 2001), which was associated with the deposition of 800-m-thick upper Miocene sequence consisting of alluvial fan deltas and alluvial fan deposits (Fig. 8A, stratigraphic section).…”

Section: Extensional Structuresmentioning

confidence: 99%

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Postcollisional contractional and extensional deformation in the Aegean region

Κοκκάλας¹,

Xypolias²,

Koukouvelas³

et al. 2006

Postcollisional Tectonics and Magmatism in the Mediterranean Region and Asia

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In the Aegean area, distinct fault patterns with their associated stress regimes are evidenced along a curved convergent plate boundary. In this article, we analyze and review late collisional and extensional structures in five structural regions along the External Hellenides orogenic belt in order to define, primarily, the evolution of onshore basins and, secondarily, the evolution of off-shore basins and the role of the inherited structures within the present geotectonic framework. We also evaluate how these structures act on seismicity as well as present-day motion and magmatism in the Aegean area.Northwestern Greece, which corresponds to our Region I, represents an area of active continental collision in which a previously overthickened crust collapsed mainly parallel to the structural grain of the orogen. At present, the most active structures in this region are the northwest-trending thrusts and the northeast-trending normal faults. Strong coupling and the transmission of horizontal forces from the collision front appear to explain the deformation within this region.Central Greece (Region II) displays a mixed type of contractional-extensional deformation. Mesozoic inherited transverse structures are reactivated as WNWtrending faults and appear to accommodate most of the active north-south-trending present-day extension. Deformation in this area appears to be controlled both by rollback of the subducting slab and by the lateral extrusion of the Anatolia plate.The areas that spread along the more curved parts of the Hellenic arc (Regions III and V) well emphasize the control exerted by pre-existing northeast-trending structures as well as their long-lived activity during the evolution of the arc. Present deformation within these regions possibly reflects the oblique convergence process, which is occurring in both areas in different degrees.Finally, analysis of deformation patterns in the central part of the Hellenic arc and the Aegean Sea (Region IV) suggests that almost all pre-existing structures have remained active until the present and accommodate extensional deformation and rapid motion through a nonorthogonal fault system that crosscuts a thin and thermally weakened continental crust. Deformation north of our Region IV is accommodated 97 *

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Section: Extensional Structuresmentioning

confidence: 98%

Section: General Tectonic Frameworkmentioning

confidence: 99%

Section: Structural Region Iv: Central Part Of the Hellenic Arcmentioning

confidence: 99%

Section: Contractional Structuresmentioning

confidence: 99%

Section: Extensional Structuresmentioning

confidence: 99%

See 3 more Smart Citations

Postcollisional contractional and extensional deformation in the Aegean region

Κοκκάλας¹,

Xypolias²,

Koukouvelas³

et al. 2006

Postcollisional Tectonics and Magmatism in the Mediterranean Region and Asia

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The 2022–2023 seismic sequence onshore South Evia, central Greece: evidence for activation of a left-lateral strike-slip fault and regional triggering of seismicity

Serpetsidaki,

Ganas

2024

J Seismol

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On 29 November 2022, an earthquake of ML 5.0 (Mw 4.8) occurred onshore South Evia Island (central Greece) preceded by a ML 4.7 (Mw 4.6) event. The pattern of relocated aftershocks indicates the activation of a single, near-vertical fault segment, oriented NW-SE at shallow crustal depths (6–11 km). We suggest that both events ruptured a blind, left-lateral strike-slip fault, about 5 km southeast of village Almyropotamos. We observed that a clear foreshock activity (N=55 events) existed before the two moderate events. The impact of the static stress loading on neighboring fault planes diminishes after a distance of 7 km from the November 2022 epicenters, where the static stress falls below +0.1 bar. We further explore triggering relationships between the 29 November events and the late December 2022 moderate events (ML 4.9) that occurred about 60 km toward NW in the Psachna and Vlahia regions of central Evia. We present evidence of possible delayed dynamic triggering of the late December 2022 central Evia sequence, based on marked changes in seismicity rates and on measured peak ground velocities (PGVs) and peak dynamic strains, both exhibiting local maxima in their map distributions. The causes of the delayed triggering may be related to the well-known geothermal field in central/north Evia and the NW-SE strike of the seismic fault.

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