European Margin Research Articles

New Mesozoic APWP for Adria aided by data from the Transdanubian Range Unit – Tectonic interpretation in the Europe – Africa geodynamic system

Mesozoic paleomagnetic data from the Transdanubian Range Unit (TRU) of the Pannonian Basin has been revised and updated to enable its paleogeographic evolution within SE Europe to be evaluated. After a 30° declination correction, the TRU data are fully consistent with those for Adria which has an almost identical stratigraphic history. This enabled a revised Apparent Polar Wander Path (APWP) to be constructed for the combined data. Comparing this with the corresponding African and European APWP shows that Adria separated from Europe around 190 Ma, then moved independently southwards between 170–120 Ma (a 30° clockwise rotation changing to counter-clockwise around 155–145 Ma). After 155 Ma, there was a northward movement that brought Adria close to the stable European margin by 115 Ma. This latter may have been with or independently of Africa. After 100 Ma, Africa and Adria moved in coordination until the end of the Cretaceous. This sequence of events correlated well with geologically established tectonic events. These include the major extensional phases in the Alpine Tethys during the southward shift and large clockwise rotation (170–155/145 Ma). This was followed by ophiolite obduction in the Neotethys (West and East Vardar) around 155–145 Ma as a result of the dramatic reversal in the displacement of Adria. Finally, around 115 Ma, the TRU was emplaced over Austroalpine units as a thick nappe associated with the general uplift in the Adriatic realm.

Not-Russians on TV

Abstract This article discusses portrayals of a Ukrainian and a Polish character on the US sitcom 2 Broke Girls (2011–2017). The pilot episode reveals that the showrunners used stereotypes of Russian characters to establish different national origins for Oleg and Sophie. The show perpetuates offensive stereotypes of Slavic and postsocialist characters to elide differences from Russians but with notable distinctions—stemming from Oleg and Sophie's economic backgrounds in the struggling postsocialist economies of the 1990s. American television has produced many comedic characters from the European margins (Greek, Czech, Ukrainian, Polish, Latvian, or from invented but East European-coded lands) who were understood as chaotic but loveable. Crucially, however, they were not Russian. From the late Cold War through the 2010s, Russianness onscreen seems to consistently signal dishonesty, danger, or hopelessness for Western audiences. This suggests that while stereotypes persist, in comedy, at least, showrunners use East Europeans to support, not threaten, American characters, further othering Russianness.

Vegetation response in NW Mediterranean borderlands to the millennial-scale climate variability of the last glacial period

Deep-sea pollen records from the Western European margin show that during the Last Glacial period (115-27 ka), regional vegetation oscillated between steppe and open forest in response to the millennial scale climate variability, Dansgaard-Oeschger (D-O) cycles and Heinrich events (HE), and that the magnitude of the forest expansions during D-O warming events was modulated by orbital parameters. However, little is known about the vegetation response in the northwestern Mediterranean region. Here, we present a new well-chronologically constrained high-resolution marine pollen record from the Gulf of Lion documenting the NW Mediterranean vegetation response during Marine Isotope Stages (MIS) 4 and 3. The pollen record highlights the strongest forest expansions during D-O 17-16 and D-O 8 in NW Mediterranean borderlands, likely driven by minima in precession. In this region, Heinrich Stadials (HS) 5 and 4 are marked by steppe landscapes while temperate forest surprisingly characterized HS 6. We hypothesize that the combination of minima in precession and local atmospheric and marine processes allows the development of the temperate forest in NW Mediterranean while the expansion of open environments occurred in other areas of Western Europe. In addition, our results support the hypothesis of Picea survival in NW Mediterranean during MIS 4 to 3.

On the Rhodopean protoliths and their Middle Jurassic to Early Cretaceous evolution. A review

The Rhodope Massif represents a large high-grade metamorphic complex situated in the Balkan Peninsula, straddling the border between Bulgaria and Greece. Geological studies carried out during the last thirty years clearly established that the complex is composed of three major lithotectonic units characterized by differing protolith ages and Alpine thermotectonic evolution. The Rhodope Massif consists of Upper and Lower terranes representing continental fragments composed mainly of pre-Mesozoic magmatic rocks and covered by Early Mesozoic sedimentary sequences. These two entities are separated by an Intermediate Terrane comprising a Jurassic magmatic arc and its host rocks tectonically intercalated with Jurassic ophiolitic fragments together with the Early Mesozoic sediments. Detailed analyses of the previously published geochronological data revealed that the three main tectonic terranes were juxtaposed in the Late Jurassic–Early Cretaceous during the continental collision and northward subduction of the Lower and Intermediate terranes. These rocks experienced Middle Jurassic to Early Cretaceous high-pressure metamorphism, followed by high-temperature one accompanied by anatexis. At that time, the Upper Terrane was metamorphosed and deformed only partially. Being part of the European margin, this terrane represented an upper continental plate during the subduction, and therefore is not considered as a part of the Alpine Rhodope metamorphic complex. It is important to note that, although most of the present-day fabric and major tectonic zones in the Rhodope metamorphic complex are younger than Early Cretaceous, and therefore they postdate the geological evolution discussed in this study, they often reactivate the old boundaries between the main terranes and units.

Lithospheric- and crustal-scale controls on variations in foreland basin development in the Northern Alpine Foreland Basin

The Northern Alpine Foreland Basin (i.e., Molasse Basin) developed due to flexural subsidence from slab- and topographic loading during continental collision between the Adriatic and European plates. Previous studies highlight a diachronous transition from underfilled- to overfilled conditions in the Molasse Basin in response to orogen-parallel variations in flexural subsidence and sediment supply. In this contribution, we investigate the lithospheric- and crustal-scale orogenic process(es) that generated this diachronous transition. For this, we conducted a tectonostratigraphic analysis of the Molasse Basin. Firstly, we constructed a 3D geological model to derive the architecture of the European margin during the Eocene onset of flexure. Second, 2D/3D reflection seismic- and borehole data were used to characterise the spatiotemporal development of depositional environments and syn-flexural normal fault kinematics in the German Molasse. Our data show a stepwise rather than continuous eastward migration of the underfilled- to overfilled transition. Furthermore, syn-flexural fault kinematics document a Rupelian to early Burdigalian northward younging trend and higher cumulative Cenozoic offsets in the Eastern German Molasse (< 230 m) compared to the Western German Molasse (< 150 m). This implies a west-to-east increase in the curvature of bending of the European plate, induced by along-strike variations in the magnitude of applied loads and/or European lithospheric strength variations. These variations drove lateral variations in accommodation space and sediment supply. Subsequently, this led to the diachronous underfill-to-overfilled transition in the Molasse Basin. Taken together, we suggest that the diachronous transition was driven by spatiotemporal variations in the thickening of the orogenic wedge supported by slab detachment, promoted by subduction- and collision of the irregular European margin.

The Alpine Geological History of the Hellenides from the Triassic to the Present—Compression vs. Extension, a Dynamic Pair for Orogen Structural Configuration: A Synthesis

In this paper, the Hellenic orogenic belt’s main geological structure and architecture of deformation are presented in an attempt to achive a better interpretation of its geotectonic evolution during Alpine orogeny. This study was based not only on recent research that I and my collaborators conducted on the deformational history of the Hellenides but also on more modern views published by other colleagues concerning the Alpine geotectonic reconstruction of the Hellenides. The structural evolution started during the Permo–Triassic time with the continental breaking of the supercontinent Pangea and the birth of the Neotethyan ocean realm. Bimodal magmatism and A-type granitoid intrusions accompanied the initial stages of continental rifting, followed by Triassic–Jurassic multiphase shallow- and deep-water sediment deposition on both formed continental margins. These margins were the Apulian margin, containing Pelagonia in the western part of the Neotethyan Ocean, and the European margin, containing continental parts of the Serbo-Macedonian and Rhodope massifs in the eastern part of the Neotethyan ocean. Deformation and metamorphism are recorded in six main deformational stages from the Early–Middle Jurassic to the present day, beginning with Early–Middle Jurassic Neotethyan intra-oceanic subduction and ensimatic island arc magmatism, as well as the formation of a suprasubduction oceanic lithosphere. Compression, nappe stacking, calc-alkaline magmatism, and high-pressure metamorphic events related to subduction processes alternated successively over time with extension, orogenic collapse, medium- to high-temperature metamorphism, adakitic and calc-alkaline magmatism, and partial migmatization related to the uplift and exhumation of deep crustal levels as tectonic windows or metamorphic core complexes. A S- to SW-ward migration of dynamic peer compression vs. extension is recognized during the Tertiary Alpine orogenic stages in the Hellenides. It is suggested that all ophiolite belts in the Hellenides originated from a single source, and this was the Neotethyan Meliata/Maliac-Axios/Vardar ocean basin, parts of which obducted during the Mid–Late Jurassic on both continental margins, Apulian (containing Pelagonia) and European (containing units of the Serbo-Macedonian/Rhodope nappe stack), W-SW-ward and E-NE-ward, respectively. In this case, the ophiolite nappes should be considered far-traveled nappes on the continental parts of the Hellenides associated with the deposition of Middle–Late Jurassic ophiolitic mélanges in basins at the front of the adjacent ophiolite thrust sheets. The upper limit of the ophiolite emplacement are the Mid–Upper Jurassic time(Callovian–Oxfordian), as shown by the deposition of the Kimmeridgian–Tithonian Upper Jurassic sedimentary carbonate series on the top of the obducted ophiolite nappes. The lowermost Rhodope Pangaion unit is regarded as a continuation of the marginal part of the Apulian Plate (External Hellenides) which was underthrust during the Paleocene–Eocene time below the unified Sidironero–Kerdylia unit and the Pelagonian nappe, following the Paleocene–Eocene subduction and closure of a small ocean basin in the west of Pelagonia (the Pindos–Cyclades ocean basin). It preceded the Late Cretaceous subduction of the Axios/Vardar ocean remnants below the European continental margin and the final closure of the Axios/Vardar ocean during the Paleocene–Eocene time, which was associated with the overthrusting of the European origins Vertiskos–Kimi nappe on the Sidironero–Kerdylia nappe and, subsequently, the final collision of the European margin and the Pelagonian fragment. Subsequently, during a synorogenic Oligocene–Miocene extension associated with compression and new subduction processes at the more external orogenic parts, the Olympos–Ossa widow and the Cyclades, together with the lower-most Rhodope Pangaion unit, were exhumed as metamorphic core complexes.

Margin processes sculpting a land-detached canyon-channel system: the Gollum Channel System in the Porcupine Seabight

The land-detached Gollum Channel System (GCS) is one of very few large-scale canyon-channel systems on the Northwest European margin and thought to be of high importance in both along-slope and downslope sediment transport processes in the Porcupine Seabight basin. It is, however, unknown when this system was formed and how active it has been throughout its evolution, making it difficult to assess its regional impact. Here, using well data integrated with airgun seismic reflection data, a seismic stratigraphy (Cretaceous to present) is built for the GCS for the first time. We find that, contrary to what was thought before, the GCS was formed before Quaternary glaciations occupied the continental shelf and its origin is tentatively associated to a phase of Northeast Atlantic margin tilting in the early Pliocene. Each of the channels that make up the GCS was initiated by incision from erosive downslope gravity flows originating on the Celtic Sea Shelf. Gravity flows from Quaternary glacial processes reused the channels and mostly bypassed the upper slope or contributed to the channel fill, though some flows were capable of erosion of existing channel flanks and incision of several smaller channels. Additionally, we show that this margin was incised by erosive gravity flows on several occasions through time and that these incisions seem to follow preferential pathways. Interaction with along-slope bottom currents from the start of the Quaternary onwards was crucial to distribute sediments and nutrients to sediment drifts and cold-water coral mounds further north (downstream) along the Irish margin.

Volcanic debris avalanche deposits and their significance in the architecture and evolution of the Miocene-Quaternary Călimani-Gurghiu-Harghita volcanic range (Eastern Transylvania, Romania)

The Călimani-Gurghiu-Harghita volcanic range (CGH) represents the surface manifestation of the post-collisional magmatism that followed the docking of its basement, the Dacia Mega Unit, onto the East European margin. Between ca. 11 and 0.3 Ma, detachment of subducted slab, magma generation, and volcanic activity in CGH propagated south-southeastward, sub-parallel with the collisional Eastern Carpathian Orogen, resulting in the construction of a series of mostly composite volcanoes dominated by calc-alkaline lavas and pyroclastic products. The generally well-preserved axial row of the CGH volcanic edifices is accompanied by voluminous volcaniclastic deposits of which sources and emplacement history persist as a matter of debate. In the standard view reflected in regional scale geologic maps, these deposits represent products of complete erosion of hypothetical earlier volcanoes. Other interpretation, however, suggest that they are at least partially constituted by voluminous volcanic debris avalanche deposits (VDADs).By combining evidence from field observation and GIS analysis with published and new data from petrography, bulk-rock geochemistry, and K/Ar geochronology, here we demonstrate that VDADs vastly dominate these volcanoclastic deposits. In addition to two previously identified VDADs (Western Călimani and Vârghiş), we show that further six VDADs (Eastern Călimani, Fâncel-Lăpuşna, Ostoroş, Ivo-Cocoizaş, Luci, and Pilişca) were generated due to the sector failure of a series of CGH volcanoes, most of which still preserve well-distinguishable collapse scars. Based on our estimates, debris avalanches with volumes between <1 km3 and > 100 km3 displaced 0.4–39% of the source edifices, transferring nearly a third of their cumulated volcanic output to the observed volcaniclastic deposits.K/Ar age constraints suggest VDAD formation closely followed in space and time the migrating volcanic activity between ca. 7.8 and 1.5 Ma. Relying on this age pattern, collapse scar orientations, and VDAD runout directions, we propose that regional scale deformation of the Dacia lithosphere imposed by progressive detachment of the underlying subducted slab, manifested on the surface as a transient subsidence–uplift couple traveling along CGH as well as opening of intramountain basins at the eastern flank of the range, was responsible for basement tilting and faulting that destabilised the CGH volcanic edifices. Seismic activity associated with slab detachment and shallow crustal fault system as well as explosive volcanic eruptions may have triggered the collapse of these edifices, leading to the generation of the VDADs.

Marine Isotope Stage 4 (71–57 ka) on the Western European margin: Insights to the drainage and dynamics of the Western European Ice Sheet

Marine Isotope Stage 4 (71–57 ka) on the Western European margin: Insights to the drainage and dynamics of the Western European Ice Sheet

PETROGRAPHY OF PYROBITUMENS IN MIDDLE – LATE JURASSIC SANDSTONES FROM THERMALLY DEGRADED HYDROCARBON ACCUMULATIONS, EAST GREENLAND

A number of exhumed hydrocarbon traps have been described from the Traill Ø region of East Greenland. This study focuses on the Bjørnedal area where the distribution of bitumen has been mapped out. Bitumen staining clearly has a cross‐cutting relationship to stratigraphic units and can be shown to form distinct palaeo‐accumulations. Detailed petrographic studies show that bitumen occurs as late diagenetic phases in Middle to Late Jurassic sandstones, and is present both as both grain‐coating and pore‐filling phases. Geochemical analyses confirm that the bitumen is organic in composition and is composed largely of carbon and hydrogen. Both H/C ratios and bonds identified by FTIR behave as expected with increasing maturity measured using bitumen reflectance. Together, these results provide strong evidence that the material is pyrobitumen derived from the in situ thermal degradation of a liquid hydrocarbon precursor. On the basis of textures in transmitted and reflected light and quantitative bitumen reflectance distributions, two populations of pyrobitumen may be recognised in some samples.Two phases of Paleogene magmatism occurred in the Traill Ø region. The first late Paleocene – early Eocene phase was related to the opening of the northern North Atlantic in the earliest Eocene, and was experienced throughout East Greenland and the northwest European margin. The later magmatic phase was related to the gradual separation of the Jan Mayen microcontinent from East Greenland through the late Eocene – early Oligocene. A single pyrobitumen phase is recognised in accumulations only affected by the early magmatism, and a second phase is only observed in areas affected by both the early and later magmatism. This relationship is interpreted as evidence for a direct relationship between magmatic phases and bitumen generation. The presence of bitumen formed by the thermal degradation of liquid hydrocarbons during the later magmatic event suggests that a viable petroleum system remained active following the early magmatic event.

The spatial and temporal distribution of neodymium isotopic composition within the Rockall Trough

Rare Earth Element (REE) concentrations and Nd isotopic compositions (εNd) of five new seawater profiles scattered across the Rockall Trough (North-East Atlantic) were investigated in order: (1) to establish the seawater εNd distribution in the Rockall Trough, which is poorly known so far; (2) to identify the southward-flowing Wyville-Thompson Ridge Overflow Water (WTOW) originating from the Nordic Seas; (3) to evaluate the potential impact of lithogenic sources on the seawater εNd in the Rockall Trough. Combined with two previously published seawater stations, the results reveal a spatial εNd gradient in the upper layer (roughly the first 900 m) of the Rockall Trough with εNd values ranging from −14.9 ± 0.3 to −11.6 ± 0.2. The influence of Nd lithogenic inputs through seawater-sediment interactions have been found to be likely negligible, so the spatial gradient has been attributed to the relative influence of unradiogenic Subpolar Gyre (SPG) water carried by the North Atlantic Current (NAC) and more radiogenic water derived from the Subtropical Gyre (STG) flowing into the Shelf Edge Current (SEC) along the European margin. Freshwater from the interior seas (Northern UK) is an additional source of radiogenic εNd, although it seems restricted to the shallow continental shelf. Below the upper layer, WTOW has been characterized for the first time with εNd (mean value of −13.8 ± 0.5; n = 9) as a homogeneous intermediate water body between 600 and 1200 m. The results reveal a strong modification of the outflowing water from the Norwegian Sea that cascades through the Wyville-Thompson ridge, as WTOW in the Rockall Trough is composed of more than 80 % Atlantic water. On the western flank of the Rockall Trough, a deep WTOW component has been identified that is responsible for a modification of the Labrador Sea Water (LSW) εNd values (-13.0 ± 0.3 to −12.1 ± 0.3). Two stations separated by only a few kilometers from each other but sampled four years apart (2012 and 2016) show a multi-annual variation of water properties and εNd values (∼1 ε-unit) for the first 800 m, pointing to a change in the relative contribution of both SPG and STG to the composition of water flowing in the Rockall Trough to the Nordic Seas. Overall, these results confirm that εNd can be used to assess the water mass composition in the Rockall Trough, allowing to reconstruct North Atlantic gyre dynamics in paleoceanographic studies.

Did the Western and the Eastern Vardar ophiolites originate through a single intra-oceanic subduction? Insight from numerical modelling

The ophiolites of the Balkan Peninsula are distinguished into the Western and the Eastern Vardar ophiolites and it is generally accepted that both of them resulted from the latest Jurassic/earliest Cretaceous closure of the Vardar branch of the Tethys Ocean (Vardar Tethys). This study is aimed at testing the possibility that the origin and emplacement of these two ophiolite belts can be explained in terms of a single NE-dipping intra-oceanic subduction, which commences in mid Jurassic and lasts until the lowermost Cretaceous, and then transitions into collision between the African and the European plate. The subduction is accompanied by creation of a new oceanic lithosphere in the back-arc. In order to test this hypothesis, we use 2D numerical thermomechanical modeling for investigating the nucleation of the East Vardar Ocean in the back-arc and intra-arc region. Our numerical results suggest that a single intra-oceanic subduction can indeed be simultaneously responsible for both the westward obduction of the Western Vardar ophiolites and for complex active margin processes along the western rim of the European plate. The simulations show that the single intra-oceanic subduction zone is able to produce a pronounced extension and oceanic spreading along the European margin, which can be associated with the formation of the Eastern Vardar ophiolites in this subduction related setting (SSZ and BAB). The comparison of the numerical modeling results with available natural data suggests that our models are capable to approximate the regional geodynamic evolution during and immediately after the closure of Vardar Tethys.

Structure and petroleum systems of the Eastern Carpathians, Romania

The Eastern Carpathian fold and thrust belt of Romania is one of the oldest oil and gas producing areas in the world. Numerous fields have been discovered in this region since the 1850s, however, their distribution is irregular with most of them clustered in the Moinesti area. Our analysis suggests that although aspects of hydrocarbon generation, reservoir presence and quality are rather similar along the strike of the entire thrust belt, recent uplift and erosional unroofing of the Carpathians ultimately controlled the preservation of oil and gas fields. Areas with the highest amount of exhumation and associated trap breaching, seem to have suffered more intense deformation due to late inversion, which in turn, reflects the rheology of the various basement units of the East European Margin underlying the Carpathians.

New insights into tectonic relations between the Eastern Vardar Ophiolitic and Serbo-Macedonian units: Inferences from a microtectonic study in central Serbia

A microtectonic study was conducted in the Levac region of central Serbia. Here, the tectonic contacts between the Europe?derived units, including the Serbo-Macedonian unit and Jurassic sedimentary cover of the European margin, and the Eastern Vardar Ophiolitic unit, are exposed at the surface. The results indicate that the contact zone underwent at least two ductile contractional deformation phases. The older contraction was associated with the formation of isoclinal folding and top-to-SE shearing in the immediate contact between the Eastern Vardar ophiolites and the Jurassic sedimentary cover of the European continental margin. This older contractional phase was likely associated with thrusting during the latest Jurassic obduction of the Eastern Vardar ophiolites over the European margin. The thrusting of the Eastern Vardar ophiolites created a sub-ophiolitic melange currently preserved in a narrow zone at their contact with the underlying Jurassic sediments, which in turn underwent metamorphism in the lower greenschist facies. The obduction-related deformation was highly overprinted by a younger, top-to-W contraction associated with the Cretaceous-Paleogene continental collision between Europe-and Adria-derived units.

Late extension of a passive margin coeval with subduction of the adjacent slab: The Western Alps and Maghrebides files

The evolution of the Alpine Tethys margins during the beginning of the African-Eurasian convergence was little studied compared to their evolution during the post-Pangea rifting and oceanic expansion,i.e., from the Early Jurassic to the early Late Cretaceous. The present work firstly aims to make up for this shortcoming in the case of the distal European margin of the Alpine Tethys, namely the Briançonnais domain of the Western Alps. We show that this margin was affected by strong post-rifting extension mainly in Late Cretaceous-Paleocene times and propose to make it the type of the (rare) “Late Extension Passive Margins”. Remarkably, this extension shortly preceded Lutetian times, when Briançonnais margin encroached the SE-dipping subduction zone under the Adria microplate. Secondly, we assess the post-rifting evolution of the north-Tethyan paleomargin in the Maghrebides transects,i.e., south-west of the Briançonnais transect along the same European-Iberian paleomargin. For this purpose, we consider the Triassic-Eocene series of the “Dorsale Calcaire” in the Alkapeca Blocks located along southeastern Iberia until the Eocene then transported onto the North African margin. Examination of the literature shows that the Tethyan margin of the Alboran block was strongly affected by normal faulting as early as Late Jurassic-Early Cretaceous times whereas post-rifting extension of the Kabylian blocks mainly occurred in the Late Cretaceous-Paleocene like in the Briançonnais. We propose that post-rifting extension of the Alboran block southern margin resulted from the sinistral movement of Africa relative to Iberia while the later extension of the Kabylian blocks can be related to the further convergence kinematics. Subduction of the Ligurian-Maghrebian slab under the North African margin would have occurred at that time in the southward continuation of the Alpine subduction. The overriding Adria and North African margins did not experience significant compression at that time. During the Eocene, a subduction polarity reversal occurred, which was associated with the relocation of the subduction zone along the Alkapeca block. This was the beginning of the Apenninic subduction, which triggered the back-arc opening of the Mediterranean basins.

Distal tephras along the SE European margin date powerful explosive eruptions from the Elbrus volcanic center (Greater Caucasus)

Knowledge of temporal patterns of past explosive eruptions is necessary to understand possible future eruptive behavior. However, volcanic records based on geological reconstructions remain incomplete. This inference is true not only for remote and sparsely populated areas like the Aleutian or Kurile-Kamchatka arcs, but also for Europe, where past large explosive events are continuously recognized in the geological record. Here we report the first age and geochemical data on the violent middle to late Pleistocene explosive eruptions from the Elbrus volcanic center (Greater Caucasus), which towers over the densely populated regions in southern Russia and Georgia. We attribute six disparate ash deposits found in the terrestrial and marine sediments along the SE European margin to the Elbrus volcanic center based on major and trace element compositions of individual shards of volcanic glass and radiogenic Sr-Nd-Pb isotope compositions of bulk tephra. We suggest that these deposits represent products of five different eruptions that were dispersed over distances of more than 150–560 km from their source. Three of four eruptions are dated at 522 ± 36, 258 ± 13, and 84.6 ± 7.4 ka by a combined zircon U–Th–Pb and (U–Th)/He approach. One sample revealed an overdispersed spectrum of single crystal (U–Th)/He dates with an average of 176 ± 40 ka. Zircon characteristics and statistical deconvolution of the geochronology data suggest that this sample contains zircon crystals from two different eruptions tentatively dated at 156.5 ± 7.7 ka and 222.8 ± 13 ka. These eruption ages represent the first recognition of a suite of large pumiceous eruptions from the Elbrus volcanic center postdating the previously known explosive activity, documented by ∼800 ka old welded tuffs. These data also provide the first geochemical and geochronological characterization of both proximal and distal Elbrus tephra glasses and contribute to the global tephra database, permitting the identification of Elbrus tephras in distal terrestrial and marine paleoenvironmental archives and hence their use as paleoclimate and archaeological markers. We consider the significance of the identified tephras for paleoenvironmental research and show their potential for tephrochronological studies in the East European Plain and adjacent areas.

Rift-related paleogeography of the European margin in the Eastern Alps (Central Tauern Window)

Continent-derived tectonic units in the Tauern Window of the Alps exhibit stratigraphic and structural traces of extension of continental margins eventually leading to the opening of the Alpine Tethys. In this study, we reassess lithostratigraphic data from the central part of the Tauern Window to reconstruct the post-Variscan evolution of this area, particularly the rift-related geometry of the European continental margin. The lithostratigraphy of the Alpine nappes reflects systematic variations of the structure of the European margin. The lowest tectonic units (Venediger nappe system, Eclogite Zone and Trögereck Nappe) are characterized by a thick succession of arkose-rich Bündnerschiefer-type sediments of probably Early Cretaceous age that we interpret as syn-rift sequence and which stratigraphically overlies thinned continental basement and thin pre-rift sediments. In contrast, the highest tectonic unit derived from Europe (Rote Wand Nappe) preserves a thick pre-rift sedimentary sequence overlying thinned continental basement, as well as a thick syn- to post-rift succession characterized by turbiditic Bündnerschiefer-type sediments of probable Cretaceous age. These observations point towards a highly segmented structure of the European rifted margin. We propose that this involved the formation of an outer margin high, partly preserved in the Rote Wand Nappe, that was separated from the main part of the European margin by a rift basin overlying strongly-thinned continental crust. The along-strike discontinuity of the Rote Wand Nappe is proposed to reflect the lateral variation in thickness of the outer margin high that resulted from margin-parallel segmentation of the European continental crust during highly oblique rifting antecedent to the opening of Alpine Tethys.

National Peripheries and Cultural Heritage: Community Building on the European margins

El present treball analitza diferents processos de patrimonialització en àrees perifèriques del sud-oest europeu (frontera hispà-lusitana en el Baix Guadiana) i el centre (República Txeca, Eslovàquia i Polònia), definint la condició perifèrica de les fronteres des de les perspectives geogràfica i socioeconòmica. Es presta una especial atenció a iniciatives de desenvolupament comunitari a través de la mobilització entorn del patrimoni, és a dir, la participació de comunitats locals en activitats relacionades amb la valorització del patrimoni, les estratègies de participació i els actors d'aquests processos socials. Malgrat les diferències entre els processos històrics dels països seleccionats i analitzats, les seves perifèries enfronten problemes semblants, als que donen respostes diferents. A través de la descripció de casos locals, aquest article explora la diversitat i les especificitats de la *patrimonialización en regions perifèriques, com ara el rol de la (*in)estabilitat de les fronteres, els problemes d'adaptabilitat/ resiliència de les comunitats locals, les estratègies de desenvolupament sostenible o l'equilibri entre aspectes locals/ globals de la posada en valor del patrimoni. Finalment, la descripció i interpretació permet crear nous interrogants que poden contribuir al desenvolupament de recerques futures centrades, p. ex., en el paper de les fronteres, comunicació/ cooperació entre comunitats frontereres, diferenciació al nivell de la patrimonialització, etc. This paper examines different heritagization processes in peripheral areas of Southern (the Portuguese-Spanish border in the Lower Guadiana Basin) and Central (Czech Republic, Slovakia, and Poland) Europe, while defining the peripherality of these borderland regions from a geographic as well as a socio-economic perspective. We pay particular attention to community building initiatives involving heritage mobilization, i.e., the participation of local communities in activities related to heritage enhancement, the participatory strategies, and the actors in these social processes. Despite the differences in the historical development of the countries selected, their peripheries face similar processes while generating different responses to those issues. Through the description of selected, locally based cases, the paper explores the varieties and the specifics of heritagization in peripheral regions (such as the role of in/stability of the borders, issues around the adaptability/resilience of local communities and sustainable growth strategies as well as the balance of local/global aspects in heritagization). Finally, the description and interpretation of the cases brings up new questions and addresses new issues which can be analysed and developed in further research (e.g., the role of the boundaries, communication/cooperation in cross-border communities, the differentiation of heritagization, etc.). El presente trabajo analiza distintos procesos de patrimonialización en áreas periféricas del suroeste europeo (frontera hispano-lusa en el Bajo Guadiana) y Centroeuropa (República Checa, Eslovaquia y Polonia), definiendo la condición periférica de las fronteras desde las perspectivas geográfica y socioeconómica. Se presta una especial atención a iniciativas de desarrollo comunitario a través de la movilización en torno al patrimonio, es decir, la participación de comunidades locales en actividades relacionadas con la valorización del patrimonio, las estrategias de participación y los actores de estos procesos sociales. A pesar de las diferencias entre los procesos históricos de los países seleccionados y analizados, sus periferias enfrentan problemas semejantes, a los que dan respuestas distintas. A través de la descripción de casos locales, este artículo explora la diversidad y las especificidades de la patrimonialización en regiones periféricas, tales como el rol de la (in)estabilidad de las fronteras, los problemas de adaptabilidad/ resiliencia de las comunidades locales, las estrategias de desarrollo sostenible o el equilibrio entre aspectos locales/ globales de la puesta en valor del patrimonio. Por último, la descripción e interpretación permite crear nuevos interrogantes que pueden contribuir al desarrollo de investigaciones futuras centradas, p. ej., en el papel de las fronteras, comunicación/ cooperación entre comunidades fronterizas, diferenciación al nivel de la patrimonialización, etc.

Diversity and distribution of bivalve molluscs in the Central Cantabrian Sea and the Avilés Canyons System (Bay of Biscay)

Bivalve molluscs is one of the dominant benthic groups in soft-sediment communities off the Atlantic Ocean, including the European margin and the Bay of Biscay. The current knowledge of deep-sea Euro-Atlantic bivalves and their distribution is still far from comprehensive and has been the scope of several recent publications. We examined the collected bivalve samples from two oceanographic campaigns (COCACE and BIOCANT) carried out in the central Bay of Biscay, including the Avilés Canyons System (ACS), a Site of Community Importance within the Natura 2000 Network. Bivalve specimens were collected from the continental shelf, slope and bathyal zones, ranging in deep from 25 to 4700 m. This is the first study focused on bivalve diversity from the Cantabrian Sea that covers such a wide bathymetric range. Eighty-four live taxa in 36 families were identified; Cetomya neaeroides is reported for the first time in the area. We provide photographs showing the shell diagnostic features of all recorded species. The conducted Multivariate Analysis showed three species assemblages: i) samples from shallow waters (continental shelf); ii) intermediate depths (shelf and upper slope) and iii) deep water (slope and abyssal plain). Depth was the main structuring factor that influenced the distribution of the recorded species and the higher species richness was found on the continental shelf. The feeding strategy and the substrate preference appeared as not significant factors in the zonation patterns of the studied bivalves.

Metamorphic peak estimates of the Marguareis Unit (Briançonnais Domain): New constrains for the tectonic evolution of the south‐western Alps

AbstractIn the Western Alps, while many P–T constraints are available for the high‐grade units, the dataset for the low‐grade units located along the westernmost edge of the belt remains scarcer and incomplete. To face these uncertainties, we quantify for the first time the metamorphic peak conditions of the Marguareis Unit, a fragment of European margin (Briançonnais Domain) regarded till now as very‐low‐grade unit, exposed along the boundary between Maritime and Ligurian Alps (South‐Western Alps), whose deformation history is well constrained. The Marguareis Unit is regarded as a thinned portion of the European continental margin involved in the Alpine collision. Metamorphic peak conditions reconstructed using the chlorite–phengite multi‐equilibrium approach on the Eocene siliciclastic deposits indicate that the Marguareis Unit recorded high‐pressure and low‐temperature conditions during its subduction, accretion and subsequent exhumation into the Alpine wedge.