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New, detailed geological/structural mapping and field-based structural analysis were carried out to investigate the deformation pattern of well-preserved high-pressure rocks of the Blueschist Unit exposed in SE Syros (Cyclades, Greece). Geological mapping revealed the occurrence of extensive alternations between different rock groups, as well as interfingering patterns in map-scale that are possibly the result of folding. The earlier ductile deformation phase recognized in the mapped area is associated with the development of a penetrative foliation, which was formed at eclogite/blueschist-facies conditions under peak metamorphism. The subsequent main deformation phase occurred under blueschist facies conditions synchronous with the early stages of exhumation of the high-pressure rocks. This phase is mainly associated with the formation of WNW-trending folds and a pervasive axial planar foliation linked with ESE-directed shearing. The main deformation ceased under blueschist-facies conditions, and exhumation of the rocks to greenschist-facies conditions took place under very weak and localized deformation. Greenschist retrogression observed in the southwestern part of the mapped area seems to be controlled by fluids, rather than by intense deformation and formation of major syn-greenschist shear zones. [ABSTRACT FROM AUTHOR]

We present the 1:8000 scale geological map of the northeastern sector of Mykonos Island, where an igneous, metamorphic and siliciclastic sequence is cut by the North Cycladic Detachment System (NCDS), and brittly-ductily deformed during the emplacement of the Mykonos Granite. We describe the architecture of the (ductile) Livada and (brittle) Mykonos Detachments pertaining to the NCDS. Geological mapping was functional to (i) the description of along and across strike geometrical variations of the detachments and (ii) the analysis of the deformation and strain partitioning within the deformed rocks. We show that deformation localisation differs along dip and strike for the Mykonos Detachment, which accommodated deformation both through thick and localised fault zones. Also, the ductile fabric of the Livada Detachment is characterised by a strong strain localisation, which generally decreases from eastwards. Moreover, the geological map shows that the detachments orientation allowed the local elision of the original tectono-stratigraphy. [ABSTRACT FROM AUTHOR]

We present a new geological map and new structural, petrographical and geochronological data from the Uppermost Unit of the Cretan nappe pile exposed south of the Dikti Mountains in eastern Crete (Greece). Based on these data, the Uppermost Unit in the study area can be subdivided (from bottom to top) into the Arvi Unit, Theodorii Greenschist and Asterousia Crystalline Complex (ACC)-type rocks. The ACC-type rocks have been affected by polyphase deformation (D1–D3) and metamorphism. Relics of the D1 phase are preserved as internal foliation in garnet porphyroblasts. D2 top-to-the SE shearing under upper amphibolite facies conditions led to the dominant foliation. After post-D2 exhumation, parts of the ACC-type rocks were affected by contact metamorphism of a non-exposed pluton, which intruded at a depth below 10 km during Campanian time (74±2Ma; laser ablation inductively coupled plasma mass spectrometry on zircon). This age, obtained from zircon of chiastolite hornfels, is in line with intrusion ages of ACC-type (meta)granitoids exposed on Crete and on Anafi. The S2-foliation of the ACC-type rocks was reactivated during the late phase of contact metamorphism by D3 top-to-the SE shearing. Latest Cretaceous cross-mica with low silicon content post-dates this shearing event. During middle Paleocene time, the ACC was thrust on top of the Theodorii Greenschist. This thrusting event as well as subsequent brittle thrusting of the greenschists and the ACC-type rocks on top of the prehnite-pumpellyite facies metamorphic Arvi Unit was still accommodated by top-to-the SE kinematics, which is the dominant kinematics of the Uppermost Unit on Crete and on Anafi. [ABSTRACT FROM AUTHOR]

The Movri Mountain earthquake (Mw 6.4), western Greece, was likely caused by dextral-slip along a blind high-angle fault, and generated a complex pattern of co-seismic surface ruptures southwest of the Gulf of Corinth. The mapped Nisi, Michoi, and Vithoulkas rupture segments have similar lengths (5-6 km) and vertical offset on the order of 25, 10, and 5 cm, respectively. They are commonly expressed as straight or jagged linear traces with secondary cracks radiating from the main segments. Horizontal slip vector analysis indicates extensional faulting processes for all rupture segments. Although these faults exert some control on the fluvial drainage pattern and at least one of them was ruptured during past events, their escarpments are poorly preserved. The indistinct topographic expression of the studied faults and their complex rupture patterns can be attributed to the distribution of the deformation over a blind fault. [ABSTRACT FROM AUTHOR]