TOPO-EUROPE: Coupled Deep Earth - Surface Processes in Europe

TOPO-EUROPE is a multidisciplinary international research program that addresses the interaction of processes inherent to the deep Earth (lithosphere, mantle) with surface processes (erosion, climate, sea level), which together shaped the topography of Europe. The objective of the TOPO-EUROPE project is to assess neotectonic deformation rates and to quantify related geo-risks, such as earthquakes, flooding, landslides, rock falls and volcanism. Research, incorporating iterative data interactive modelling, focuses on the lithosphere memory and neotectonics, with special attention on the thermo-mechanical structure of the lithosphere, mechanisms controlling large-scale plate boundary and intraplate deformations, anomalous subsidence and uplift, and links with surface processes and topography evolution. The TOPO-EUROPE natural laboratories, in which these processes are analysed, cover a wide range of geodynamic settings. These include the post-collisional Alpine/Carpathian/Pannonian-Basin system, the very active Aegean-Anatolian and Apennines-Tyrrhenian orogens and back-arc basins, the Caucasus-Levant area in the Arabia-Europe collision zone, the Iberian Peninsula caught up between Alpine orogens, the meta-stable West and Central European Platform, the stable East-European Platform and the seismically active and elevated Scandinavian continental margin. The TOPO-EUROPE project is a component of the International Lithosphere Program and was initiated with the support of Academia Europaea. A European Science Foundation EUROCORES project provides funding for part of the TOPO-EUROPE research. Other parts of TOPO-EUROPE require support by participating organization

Three-dimensional flexural modelling of the Ebro Basin(NE Iberia)

The Ebro Basin, the southern foreland basin of the Pyrenees, has undergone a complex evolution in which, apart from the Pyrenees, the Iberian Range and the Catalan Coastal Ranges have played an important role, both as sediment sources and as basin confining structures. The deflected basement underlying the Ebro Basin dips north, suggesting a lithospheric-scale control on the structure of this basin. This is compatible with the results of subsidence analyses, which show that the study area is not in a local mode of isostatic compensation. In order better to understand the mechanisms that led to the present configuration of the Ebro Basin, and particularly the relevance of the various kinds of (un)loading (e.g. surrounding fold-and-thrust belts, basin topography, subsurface loads), we carried out a 3-D kinematic modelling study that accounts for the flexural state of the lithosphere, subjected to various loads applied at its lateral boundaries, and the sedimentary fill of the basin. We also included the effect of Neogene extensional tectonics along the eastern basin margin, which is related to the opening of the Valencia Trough. We show the suitability of the 3-D lithospheric-scale flexural modelling approach to the study of NE Iberia. Modelling results point to a relatively strong lithosphere in this area, with values of effective elastic thickness ranging from 10 to 35 km in the Ebro Basin, increasing towards the Pyrenees. We also find that the topographic (tectonic) load itself is insufficient to explain the observed basement deflection. Thus an extra subsurface load beneath the Pyrenees, corresponding to the underthrusted Iberian lithosphere, is required. The effect of lithospheric stretching in the Valencia Trough on the Ebro Basin is appreciable only in its eastern part, where the lithosphere was uplifted. This had considerable repercussions on the sedimentary and erosional regime of the Ebro Basin. We have analysed the link between the stretching-related, tectonically uplifted areas and the erosional patterns observed onshore northeast Iberi

The granite and glacial landscapes of the Peneda-Gerês National Park

Granite and glacial landforms are presented as the main geomorphological landscape features of the Peneda-Gerês National Park. The park was established in 1971 and it is the only national park and most important protected area in Portugal. The aesthetic attractiveness is supported mainly by the distinct granite landscape of the Gerês and Peneda Mountains, where the post-orogenic Variscan Gerês gran- ite facies occurs. The rugged relief is poorly covered by vegetation, differentiating it from the surrounding moun- tainous areas and the most distinctive landforms are bornhardts, locally named as “medas”. Typical glacial landforms, such as U-shaped valleys, cirques and moraines, express the sheltered character of a low-altitude glaciation, which is of great significance in the context of the Pleistocene glaciation in Southern Europe.This work is co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Inter nacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145- FEDER-007690 and Portuguese national funds pro vided by Fundação para a Ciência e Tecnologi

Probing Tectonic Topography in the Aftermath of Continental Convergence in Central Europe

Continental topography is at the interface of processes taking place at depth in the Earth,at its surface,and above it.Topography influences society, not only in terms of slow processes of landscape change and earthquakes,but also in terms of how it affects climate.The Pannonian Basin–Carpathian Orogen System in Central and Eastern Europe represents a key natural laboratory for the development of a new generation of models for ongoing orogeny and its effect on continental topography development (Figure 1).This system comprises some of the best documented sedimentary basins in the world,located within the Alpine orogenic belt, at the transition between the western European lithosphere and the East European Craton. It includes one of the most active seismic zones in Europe,with intermediate depth (50–220 km) mantle earthquakes of significant magnitude occurring in a geographically restricted area in the Vrancea zone of southeastern Romania

Rifting in heterogeneous lithosphere inferences from numerical modeling of the northern North Sea and the Oslo Graben.

Permian rifting and magmatism are widely documented across NW Europe. The different Permian basins often display contrasting structural styles and evolved in lithospheric domains with contrasting past evolution and contrasting thermotectonic ages. In particular, the Oslo Graben and the northern North Sea rift initiated in close areas of northern Europe. The Oslo Graben evolved in the cold and stable Precambrian lithosphere of Fennoscandia, whereas the northern North Sea rift took birth in freshly reworked Caledonian lithosphere. Huge volumes of magmatic rocks characterize the relatively narrow Oslo Graben. In contrast, little magmatism is documented for the wide northern North Sea rift. Differences in timing between both rifts are inferred but still debated. We present numerical thermomechanical models along a lithospheric E-W section that involves both the Oslo Graben and the northern North Sea area. Because the modeled section crosses the boundary between Caledonian and Proterozoic provinces, thermal and compositional heterogeneities are considered. As is suggested by various geophysical data sets, we also consider lithospheric thickness heterogeneities in the Precambrian lithosphere. Modeling results suggest that the northern North Sea was on top of "weak" lithosphere very sensitive to far-field stresses. Consequently, we suggest that rifting in the northern North Sea began as early as regional extension was effective (i.e., Late Carboniferous-Early Permian) and does not postdate the Oslo Graben as it is commonly assumed. Rifting in the "strong" Precambrian lithosphere is unexpected. Modeling results suggest that a pre-existing lithospheric thickness contrast within the Fennoscandian lithosphere favored rifting in the Oslo Graben

Geokinematics of Central Europe: New insights from the CERGOP-2/Environment Project

The Central European Geodynamics Project CERGOP/2, funded by the European Union from 2003to 2006 under the 5th Framework Programme, benefited from repeated measurements of thecoordinates of epoch and permanent GPS stations of the Central European GPS Reference Network(CEGRN), starting in 1994. Here we report on the results of the systematic processing of availabledata up to 2005. The analysis has yielded velocities for some 60 sites, covering a variety of CentralEuropean tectonic provinces, from the Adria indenter to the Tauern window, the Dinarides, thePannonian Basin, the Vrancea seismic zone and the Carpathian Mountains. The estimated velocitiesdefine kinematical patterns which outline, with varying spatial resolution depending on the stationdensity and history, the present day surface kinematics in Central Europe. Horizontal velocities areanalyzed after removal from the ITRF2000 estimated velocities of a rigid rotation accounting forthe mean motion of Europe: a ~2.3 mm/yr north-south oriented convergence rate between Adria andthe Southern Alps that can be considered to be the present day velocity of the Adria indenterrelative to the European foreland. An eastward extrusion zone initiates at the Tauern Window. Thelateral eastward flow towards the Pannonian Basin exhibits a gentle gradient from 1-1.5 mm/yrimmediately east of the Tauern Window to zero in the Pannonian Basin. This kinematic continuityimplies that the Pannonian plate fragment recently suggested by seismic data does not require aspecific Eulerian pole. On the southeastern boundary of the Adria microplate, we report a velocitydrop from 4-4.5 mm/yr motion near Matera to ~1 mm/yr north of the Dinarides, in the southwesternpart of the Pannonian Basin. A positive velocity gradient as one moves south from West Ukraineacross Rumania and Bulgaria is estimated to be 2 mm/yr on a scale of 600-800 km, as if the crustwere dragged by the counterclockwise rotation along the North Anatolian Fault Zone. This regimeapparently does not interfere with the Vrancea seismic zone: earthquakes there are sufficiently deep(> 100 km) that the brittle deformation at depth can be considered as decoupled from the creep atthe surface. We conclude that models of the Quaternary tectonics of Central and Eastern Europeshould not neglect the long wavelength, nearly aseismic deformation affecting the upper crust in theRomanian and Bulgarian regions

Toward understanding the post-collisional evolution of an orogen influenced by convergence at adjacent plate margins; Late Cretaceous-Tertiary thermotectonic history of the Apuseni Mountains

The relationship between syn- to post-collisional orogenic shortening and stresses transmitted from other neighboring plate boundaries is important for understanding the kinematics of mountain belts, but has received little attention so far. The Apuseni Mountains are an example of an orogen in the interference zone between two other subduction systems located in the external Carpathians and Dinarides. This interference is demonstrated by the results of a combined thermochronological and structural field study that quantifies the post-collisional latest Cretaceous-Tertiary evolution. The exhumation history derived from apatite fission track and (U-Th)/He thermochronology indicates that the present-day topography of the Apuseni Mountains originates mainly from latest Cretaceous times, modified by two tectonic pulses during the Paleogene. The latter are suggested by cooling ages clustering around ∼45 Ma and ∼30 Ma and the associated shortening recorded along deep-seated fault systems. Paleogene exhumation pulses are similar in magnitude (∼3.5 km) and are coeval with the final collisional phases recorded in the Dinarides and with part of the Carpathian rotation around the Moesian promontory. These newly quantified Paleogene exhumation and shortening pulses contradict the general view of tectonic quiescence, subsidence and overall sedimentation for this time interval. The Miocene collapse of the Pannonian Basin did not induce significant regional exhumation along the western Apuseni flank, nor did the subsequent Carpathian collision. This is surprising in the overall context of Pannonian Basin formation and its subsequent inversion, in which the Apuseni Mountains were previously interpreted as being significantly uplifted in both deformation stages. Copyright 2011 by the American Geophysical Union