scholarly journals Palaeomagnetic evidence for non-rotational deformation along the Nea Anchialos Fault System, Central Greece

1997 ◽  
Vol 40 (4) ◽  
Author(s):  
D. Kondopoulou ◽  
R. Caputo
Keyword(s):  
Hanging Wall ◽  
Fault System ◽  
Deformation Pattern ◽  
Structural Investigations ◽  
The North ◽  
Magnetic Carriers ◽  
Rotational Deformation ◽  
North Aegean ◽  
Almost All ◽  
Paleomagnetic Direction

Four sites in 1.4 Ma old basaltic lavas and two sites in upper Pliocene-lower Quaternary sediments, located both in the hanging-wall and in the footwall blocks of the Nea Anchialos Fault System, have been sampled. This fault system is one of the major E-W trending structures affecting the Thessaly region during Quaternary times.It is possibly connected with the North Aegean Trough to the E and displays recent seismic activity (1980, Volos earthquake). Standard techniques have been used for both field sampling and laboratory analyses. The magnetic carriers were characterised by measuring the thermomagnetic curves, the anisotropy of magnetic susceptibility and the isothermal remanent magnetisation of the samples. Almost all the samples exhibit a reverse polarity. The overall mean paleomagnetic direction is defined by D = 174°, I = –54°, confirming the non-rotational deformation pattern of the Nea Anchialos Fault System as independently inferred from structural investigations.

Geodetic analysis of the tectonic crustal deformation pattern in the North Aegean Sea, Greece

2021 ◽  
Author(s):  
Ilias Lazos ◽  
Sotirios Sboras ◽  
Christos Pikridas ◽  
Spyros Pavlides ◽  
Alexandros Chatzipetros
Keyword(s):  
Crustal Deformation ◽  
Aegean Sea ◽  
Deformation Pattern ◽  
The North ◽  
North Aegean ◽  
North Aegean Sea

Recent and active deformation in the North Evia domain, a diffuse plate boundary between Eurasia and Aegean plates in the Western termination of the North Anatolian Fault. 

2021 ◽  
Author(s):  
Fabien Caroir ◽  
Frank Chanier ◽  
Virginie Gaullier ◽  
Julien Bailleul ◽  
Agnès Maillard-Lenoir ◽  
...  
Keyword(s):  
Fault Zone ◽  
Plate Boundary ◽  
Fault Zones ◽  
North Anatolian Fault ◽  
Fault System ◽  
Eurasian Plate ◽  
Slip Rates ◽  
The North ◽  
South West ◽  
North Aegean

<p>The Anatolia-Aegean microplate is currently extruding toward the South and the South-West. This extrusion is classically attributed to the southward retreat of the Aegean subduction zone together with the northward displacement of the Arabian plate. The displacement of Aegean-Anatolian block relative to Eurasia is accommodated by dextral motion along the North Anatolian Fault (NAF), with current slip rates of about 20 mm/yr. The NAF is propagating westward within the North Aegean domain where it gets separated into two main branches, one of them bordering the North Aegean Trough (NAT). This particular context is responsible for dextral and normal stress regimes between the Aegean plate and the Eurasian plate. South-West of the NAT, there is no identified major faults in the continuity of the NAF major branch and the plate boundary deformation is apparently distributed within a wide domain. This area is characterised by slip rates of 20 to 25 mm/yr relative to Eurasian plate but also by clockwise rotation of about 10° since ca 4 Myr. It constitutes a major extensional area involving three large rift basins: the Corinth Gulf, the Almiros Basin and the Sperchios-North Evia Gulf. The latter develops in the axis of the western termination of the NAT, and is therefore a key area to understand the present-day dynamics and the evolution of deformation within this diffuse plate boundary area.</p><p>Our study is mainly based on new structural data from field analysis and from very high resolution seismic reflexion profiles (Sparker 50-300 Joules) acquired during the WATER survey in July-August 2017 onboard the R/V “Téthys II”, but also on existing data on recent to active tectonics (i.e. earthquakes distribution, focal mechanisms, GPS data, etc.). The results from our new marine data emphasize the structural organisation and the evolution of the deformation within the North Evia region, SW of the NAT.</p><p>The combination of our structural analysis (offshore and onshore data) with available data on active/recent deformation led us to define several structural domains within the North Evia region, at the western termination of the North Anatolian Fault. The North Evia Gulf shows four main fault zones, among them the Central Basin Fault Zone (CBFZ) which is obliquely cross-cutting the rift basin and represents the continuity of the onshore Kamena Vourla - Arkitsa Fault System (KVAFS). Other major fault zones, such as the Aedipsos Politika Fault System (APFS) and the Melouna Fault Zone (MFZ) played an important role in the rift initiation but evolved recently with a left-lateral strike-slip motion. Moreover, our seismic dataset allowed to identify several faults in the Skopelos Basin including a large NW-dipping fault which affects the bathymetry and shows an important total vertical offset (>300m). Finally, we propose an update of the deformation pattern in the North Evia region including two lineaments with dextral motion that extend southwestward the North Anatolian Fault system into the Oreoi Channel and the Skopelos Basin. Moreover, the North Evia Gulf domain is dominated by active N-S extension and sinistral reactivation of former large normal faults.</p>

scholarly journals Propagation of a strike-slip plate boundary within an extensional environment: the westward propagation of the North Anatolian Fault

2016 ◽  
Vol 53 (11) ◽  
pp. 1416-1439 ◽  
Author(s):  
Xavier Le Pichon ◽  
A.M. Celâl Şengör ◽  
Julia Kende ◽  
Caner İmren ◽  
Pierre Henry ◽  
...  
Keyword(s):  
Plate Boundary ◽  
Strike Slip ◽  
Fault System ◽  
Plate Boundaries ◽  
Sea Of Marmara ◽  
The North ◽  
Gulf Of Corinth ◽  
Northern Border ◽  
North Aegean ◽  
Narrow Plate

We document the establishment of the Aegea–Anatolia/Eurasia plate boundary in Pliocene–Pleistocene time. Before 2 Ma, no localized plate boundary existed north of the Aegean portion of the Anatolia plate and the shear produced by the motion of Anatolia–Aegea with respect to Eurasia was distributed over the whole width of the Aegean – West Anatolian western portion. In 4.5 Ma, a shear zone comparable to the Gulf of Corinth was formed in the present Sea of Marmara. The initial extensional basins were cut by the strike-slip Main Marmara Fault system after 2.5 Ma. Shortly after, the plate boundary migrated west of the Sea of Marmara along the northern border of Aegea from the North Aegean Trough, to the Gulf of Corinth area and to the Kefalonia Fault. There, it finally linked with the northern tip of the Aegean subduction zone, completing the system of plate boundaries delimiting the Anatolia–Aegea plate. We have related the change in the distribution of shear from Miocene to Pliocene to the formation of a relatively undeforming Aegea block in Pliocene that forced the shear to be distributed over a narrow plate boundary to the north of it. We attribute the formation of this block to the northeastward progression of the oceanic Ionian slab. We propose that the slab cuts the overlying lithosphere from asthenospheric sources and induces a shortening environment over it.

scholarly journals Effects of transpression on the rocks exposed at the Jhelum Fault Zone in the east of Potwar Basin, Pakistan: implications on the subsurface deformation pattern

2021 ◽  
Author(s):  
Ibrahim Safi ◽  
Gohar Rehman ◽  
Muhammad Yaseen ◽  
Sohail Wahid ◽  
Muhammad Nouman ◽  
...  
Keyword(s):  
Fault Zone ◽  
Stress Component ◽  
Satellite Image ◽  
Fault System ◽  
Deformation Pattern ◽  
The North ◽  
Lateral Extent ◽  
Geological Map ◽  
Potwar Basin ◽  
Well Data

AbstractJhelum Fault is the north–south-oriented major structural lineament originating from the Hazara-Kashmir Syntaxis and extending southwards towards the Mangla Lake. Geographic extent, nature and significance of Jhelum Fault are the subjects which have been approached by different researchers in the past. The previous research provides enough evidence for the presence of Jhelum Fault as well as they discourse its surface extent. None of the previous research addresses the subsurface model of this fault; consequently, its surface extent has been ambiguous and variably reported. The current research takes into account both the surface lineament as well as the subsurface behaviour of the deformed strata to draft the most reasonable depiction of this fault. Field data were coupled with satellite image of 1.5 m ground resolution to produce the geological map of the study area at 1:25,000 scale. The subsurface model was created along four traverse lines by considering the lateral extent of the structures and their shifting trends on the geological map. The stratigraphic package was taken from the nearby hydrocarbon exploratory well data (Missakeswal-01 well of OGDCL) as no rocks older than middle to late Miocene were exposed in the area. The consistent through-going map extents of many faults in the study area prove that faults are playing the major role in the tectonic evolution of the Jhelum Fault Zone. In the subsurface model, the same faults show very little stratigraphic throw, which signify the major stress component to be associated more with wrenching than pure compression. Therefore, most faults in the area are of transpressional nature having dominant lateral component with relatively smaller push towards west on steeply east dipping faults. The model also shows the positive flower structure with dominantly west verging fault system with few east verging back thrusts. The subsurface proposed model shows that the Jhelum Fault is extendible southwards to the Mangla Lake in the subsurface; however, it acts like a continuous shear zone on the surface where there all the shearing is accommodated by tight refolded fold axes. The east–west shortening does not exceed 14.5% which shows smaller compression in the study area. The 3D model further clarifies the model by showing the consistency of the fault system along strike.

scholarly journals DEFORMATION PATTERN IN THE WESTERN NORTH AEGEAN TROUGH: PRELIMINARY RESULTS

2017 ◽  
Vol 50 (1) ◽  
pp. 124 ◽  
Author(s):  
D. Sakellariou ◽  
G. Rousakis ◽  
G. Vougioukalakis ◽  
Ch. Ioakim ◽  
I. Panagiotopoulos ◽  
...  
Keyword(s):  
Stress Axis ◽  
Deformation Pattern ◽  
High Angle ◽  
Seismic Profiles ◽  
Swath Bathymetry ◽  
The North ◽  
Fault Kinematics ◽  
North Aegean ◽  
Network Fault ◽  
Fault Network

Preliminary interpretation of swath bathymetry data and seismic profiles acquired during four cruises of "YPOTHER/Aegean Explorations" project aboard R/V Aegaeo provides insights into the fault network, fault kinematics and deformation pattern of the western part of the North Aegean Trough (NAT). The N40°E trending western part of the dextral North Anatolian Fault (NAF) runs along the southern margin of the NAT. Numerous high-angle fault splays initiate from and at low angle to NAF. They run firstly in NE-SW direction and then gradually turn to SE-NW forming an imbricate fault pattern, a nicely developed horsetail structure at the western termination of the NAF. The horsetail pattern deforms the NAT's sedimentary infill forming elongate, curved, uplifting or subsiding tectonic blocks arranged along the fault splays. Instead of the expected transtension, the Western NAT's infill displays dextral shearing and transpression associated with a major stress axis in NW-SE direction. The possible explanation for the transpressional deformation of the Western NAT infill may be related with the change of the trend of NAF from N40°E in the western trough to N70°E east of Lemnos Island.

scholarly journals Miocene fan delta conglomerates in the north-western part of the Danube Basin: provenance, paleoenvironment, paleotransport and depositional mechanisms

2018 ◽  
Vol 69 (5) ◽  
pp. 467-482 ◽  
Author(s):  
Tamás Csibri ◽  
Samuel Rybár ◽  
Katarína Šarinová ◽  
Michal Jamrich ◽  
Ľubomír Sliva ◽  
...  
Keyword(s):  
Pannonian Basin ◽  
Sedimentary Cover ◽  
Hanging Wall ◽  
Fault System ◽  
Danube Basin ◽  
Oblique Collision ◽  
Accommodation Space ◽  
The North ◽  
Fan Delta ◽  
Central Western Carpathians

Abstract The Blatné Depression located in the NW part of the Danube Basin represents the northernmost sub-basins of the Pannonian Basin System. Its subsidence is associated with oblique collision of the Central Western Carpathians with the European platform, followed by the back-arc basin rifting stage in the Pannonian domain. The conglomerates recognized in the Cífer-2 well document the latest Burdigalian–early Langhian deposition in fan delta lobes situated above the footwall and hanging wall of a WSW–ENE trending fault system, the activity of which preceded the opening of the late Langhian–Serravallian accommodation space with a NE–SW direction. The provenance area of the “Cífer conglomerate” was linked to the Tatric Super-unit complexes. Similar rocks crop out in the southern part of the Malé Karpaty Mts. and are also present in the pre-Cenozoic basement of the Danube Basin. Documented extensive erosion of the crystalline basement and its sedimentary cover lasted until the early/middle Miocene boundary. The “Cífer conglomerate” has distinct clast composition. The basal part consists of poorly sorted conglomerate with sub-angular clasts of metamorphic rocks. Toward the overlying strata, the clasts consist of poorly sorted conglomerates with sub-rounded to well-rounded carbonates and granitoids. The uppermost part consists of poorly sorted conglomerates with sub-rounded to rounded clasts of carbonate, granitoid and metamorphic rock. Within the studied samples a transition from clast to matrix supported conglomerates was observed.

Submarine fan deposystems and tectonics of a Late Cretaceous forearc basin along an accretionary convergent plate boundary, MacColl Ridge Formation, Wrangell Mountains, Alaska

1999 ◽  
Vol 36 (3) ◽  
pp. 433-458 ◽  
Author(s):  
Jeffrey M Trop ◽  
Kenneth D Ridgway ◽  
Arthur R Sweet ◽  
Paul W Layer
Keyword(s):  
Late Cretaceous ◽  
Compositional Data ◽  
Hanging Wall ◽  
Plate Boundary ◽  
Coarse Grained ◽  
Fault System ◽  
Forearc Basin ◽  
Submarine Fan ◽  
The North ◽  
South Central

Analysis of Upper Cretaceous sedimentary and volcanic strata in the Wrangell Mountains of south-central Alaska provides an opportunity to study the tectonics, depositional systems, and provenance of a forearc basin that developed along an accretionary convergent plate boundary. New data from the 1150 m thick MacColl Ridge Formation indicate that deposition occurred during the Campanian on a coarse-grained submarine fan that was derived from an uplifted allochthonous terrane exposed in the hanging wall of a fault system that separated the forearc basin from the subduction complex. New age controls include palynoflora indicative of a late middle to late Campanian age, and compatible radiometric age determinations of volcanic vitric-crystal tuffs near the top of the formation which have 40Ar/39Ar isochron ages of 79.4 ± 0.7 and 77.9 ± 2.1 Ma. Sedimentological and paleontological data show that sedimentation occurred on the inner portions of a sand- and gravel-rich submarine fan system. Evidence for this interpretation includes dominance of channelized sediment gravity flow deposits, particularly turbidites and debris flows; microflora indicative of open-marine conditions; unidirectional paleocurrent indicators; and syndepositional slump features. The pyroclastic eruptions that formed the vitric-crystal tuffs of the MacColl Ridge Formation are interpreted as products of the Late Cretaceous Kluane magmatic arc that bordered the forearc basin to the north. Sandstone and conglomerate compositional data combined with northward-directed paleocurrent indicators suggest that detritus was derived mainly from igneous rocks of the allochthonous Wrangellia terrane located in the hanging wall of the Border Ranges fault system along the southern margin of the basin. From a regional perspective, deposition of the MacColl Ridge Formation was coeval with the early part of Campanian-Maastrichtian synorogenic sedimentation and contractile deformation documented throughout the northwestern Cordillera.

Examining the Vulnerability Procedure: Group-based Determinations at the EU Border

2021 ◽  
Author(s):  
Karin Åberg
Keyword(s):  
Human Rights ◽  
Asylum Seekers ◽  
Aegean Sea ◽  
Detailed Account ◽  
The North ◽  
North Aegean ◽  
North Aegean Sea ◽  
The 1960S ◽  
Almost All ◽  
The Eu

Abstract Between 2016 and 2019, almost all asylum seekers who managed to reach the Greek islands in the North Aegean Sea had to undergo an assessment of their vulnerability within the EU hotspot system. Those who were found vulnerable were exempted from return under the EU-Turkey Agreement and were free to leave for the Greek mainland. This article provides a detailed account of the vulnerability procedure, which classifies migrants through pre-established categories on account of externally distinguishable features rather than individual experiences. As is shown, this type of group-based management of refugees preceded the Refugee Convention, but has since the 1960s primarily been applied in the Global South. The use of this procedure in Europe reflects an exception from the European individualist human rights approach. In the context of EU hotspots, the vulnerability procedure provides a pathway to exemption from externalisation, for those who can live up to its requirements of documentable hardship.

scholarly journals Local radon flux maxima in the quaternary sediments of Schleswig–Holstein (Germany)

2021 ◽  
Author(s):  
Johannes Albert ◽  
Maximilian Schärf ◽  
Frieder Enzmann ◽  
Martin Waltl ◽  
Frank Sirocko
Keyword(s):  
Water Content ◽  
Pore Space ◽  
Mineralogical Composition ◽  
Fault System ◽  
Near Surface ◽  
Salt Diapirism ◽  
The North ◽  
Radon Flux ◽  
Published Evidence ◽  
Tectonically Active

AbstractThis paper presents radon flux profiles from four regions in Schleswig–Holstein (Northern Germany). Three of these regions are located over deep-rooted tectonic faults or salt diapirs and one is in an area without any tectonic or halokinetic activity, but with steep topography. Contrary to recently published studies on spatial patterns of soil radon gas concentration we measured flux of radon from soil into the atmosphere. All radon devices of each profile were deployed simultaneously to avoid inconsistencies due to strong diurnal variations of radon exhalation. To compare data from different seasons, values had to be normalized. Observed radon flux patterns are apparently related to the mineralogical composition of the Quaternary strata (particularly to the abundance of reddish granite and porphyry), and its grain size (with a flux maximum in well-sorted sand/silt). Minimum radon flux occurs above non-permeable, clay-rich soil layers. Small amounts of water content in the pore space increase radon flux, whereas excessive water content lessens it. Peak flux values, however, are observed over a deep-rooted fault system on the eastern side of Lake Plön, i.e., at the boundary of the Eastholstein Platform and the Eastholstein Trough. Furthermore, high radon flux values are observed in two regions associated with salt diapirism and near-surface halokinetic faults. These regions show frequent local radon flux maxima, which indicate that the uppermost strata above salt diapirs are very inhomogeneous. Deep-rooted increased permeability (effective radon flux depth) or just the boundaries between permeable and impermeable strata appear to concentrate radon flux. In summary, our radon flux profiles are in accordance with the published evidence of low radon concentrations in the “normal” soils of Schleswig–Holstein. However, very high values of radon flux are likely to occur at distinct locations near salt diapirism at depth, boundaries between permeable and impermeable strata, and finally at the tectonically active flanks of the North German Basin.

scholarly journals Volcanism and Volcanogenic Submarine Sedimentation in the Paleogene Foreland Basins of the Alps: Reassessing the Source-to-Sink Systems with an Actualist View

Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Andrea Di Capua ◽  
Federica Barilaro ◽  
Gianluca Groppelli
Keyword(s):  
Foreland Basin ◽  
Fault System ◽  
Foreland Basins ◽  
The North ◽  
Source To Sink ◽  
The Alps ◽  
Alpine Foreland ◽  
Alpine Foreland Basin ◽  
Tectonic Lineament ◽  
First Time

This work critically reviews the Eocene–Oligocene source-to-sink systems accumulating volcanogenic sequences in the basins around the Alps. Through the years, these volcanogenic sequences have been correlated to the plutonic bodies along the Periadriatic Fault System, the main tectonic lineament running from West to East within the axis of the belt. Starting from the large amounts of data present in literature, for the first time we present an integrated 4D model on the evolution of the sediment pathways that once connected the magmatic sources to the basins. The magmatic systems started to develop during the Eocene in the Alps, supplying detritus to the Adriatic Foredeep. The progradation of volcanogenic sequences in the Northern Alpine Foreland Basin is subsequent and probably was favoured by the migration of the magmatic systems to the North and to the West. At around 30 Ma, the Northern Apennine Foredeep also was fed by large volcanogenic inputs, but the palinspastic reconstruction of the Adriatic Foredeep, together with stratigraphic and petrographic data, allows us to safely exclude the Alps as volcanogenic sources. Beyond the regional case, this review underlines the importance of a solid stratigraphic approach in the reconstruction of the source-to-sink system evolution of any basin.

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