Multiple subduction imprints in the mantle below Italy detected in a single lava flow

Post-collisional magmatism reflects the regional subduction history prior to collision but the link between the two is complex and often poorly understood. The collision of continents along a convergent plate boundary commonly marks the onset of a variety of transitional geodynamic processes. Typical responses include delamination of subducting lithosphere, crustal thickening in the overriding plate, slab detachment and asthenospheric upwelling, or the complete termination of convergence. A prominent example is the Western-Central Mediterranean, where the ongoing slow convergence of Africa and Europe (Eurasia) has been accommodated by a variety of spreading and subduction systems that dispersed remnants of subducted lithosphere into the mantle, creating a compositionally wide spectrum of magmatism. Using lead isotope compositions of a set of melt inclusions in magmatic olivine crystals we detect exceptional heterogeneity in the mantle domain below Central Italy, which we attribute to the presence of continental material, introduced initially by Alpine and subsequently by Apennine subduction. We show that superimposed subduction imprints of a mantle source can be tapped during a melting episode millions of years later, and are recorded in a single lava flow

Active faults in the Anatolian-Aegean plate boundary region with Nubia

Convergence of the Africa, Arabia, and Eurasia plates and the westward escape of Anatolia have resulted in an evolving plate boundary zone in the Eastern Mediterranean. e current location and nature of the plate boundary between the Anatolian and the African plate is di cult to trace due to the scattered crustal earthquakes and the absence of deep ones. We examine various types and locations for the plate boundary as constrained by seismicity, seismic re ection studies, tomographic studies, and geodetic measurements and we use a spherical plane stress nite element model to test these possibilities. In our regional model, we impose the convergence of Africa, Arabia, and stable Eurasia by applying GPS-derived velocities in the far- eld, as well as the roll-back of the Hellenic trench to solve for regional deformation. Model velocity and stress elds are compared with GPS-derived velocities and stress directions from focal mechanism solutions. We nd that the plate boundary via the Pliny and Strabo trenches, the Anaximander Mountains, the Eratosthenes Seamount collisional segment, and the Latakia-Larnaka ridges gives the best t to the data. e Anaximander Mountains plate boundary has both down-dip and strike-slip motions, and the Latakia segment is pure strike-slip. e Cyprus subduction contact is 42% locked. From a combined analysis of indicators for long-term deformation (predominantly slip-rates on major faults) and model results we infer that this southern plate boundary con guration may have existed since the Late Pliocene

Introduction to the Special Section in “Geodynamics, Crustal and Lithospheric Tectonics, and Active Deformation in the Mediterranean Regions” (A Tribute to Prof. Renato Funiciello)

International audienc

The Gibraltar arc: can various (near)surface observations be explained through lithospheric-scale forces?

Physical and Space Geodes

Resolution experiments for NW Pacific subduction zone tomography

We investigate the resolving power of ISC/NEIC P travel time data in tomographic inveisions for the geometry of the subduction zones in the NW Pacific. From thermal models for the Kurile, Japan, Izu-Bonin, Mariana and Ryukyu slabs, we generate three dimensional synthetic velocity anomalies for subducting slabs which are then projected onto a cell model for the uppermost 1400 km of the mantle. Using these synthetic models we compute synthetic delay times for ray paths corresponding to the source and receiver locations used for the actual data, add Gaussian noise, invert the synthetic data, and compare the resulting velocity structure to the initial synthetic models. This comparison is illustrated for sections through the Kuriles and the Mariana arcs. A variety of resolution artifacts are observed, which in many cases resemble features visible in the tomographic results obtained from inverting the actual ISC/NEIC data

The Interface Between Tectonic Evolution and Cold-Water Coral Dynamics in the Mediterranean

Circulation and water properties in the Mediterranean basin, and thus the living conditions for marine biota, including cold-water corals, are a strong function of the connectivity of the basin with neighbouring water masses. The configuration of the basin and its connections with adjacent basins are governed by the interplay of large scale and regional scale geodynamical (or tectonic) processes within the Mediterranean region. As to surface area, it appears that the Mediterranean basin as a whole is closing whereas some of its sub-basins are opening, at the expense of the eastern Mediterranean basin. More important are opening or closure of gateway connections. The pertinent Mediterranean gateways to the Atlantic Ocean and the Black Sea are potentially subject to minor changes resulting from tectonics. However, the impact of such possible changes on marine conditions, including those for cold-water corals, would be slow and of minor magnitude compared to the effects of climate change. Typical aspects of cold-water coral occurrences in the Mediterranean region, notably the uplift and outcrops of Plio-Pleistocene communities and the presence of steep faults (with steered fluid seeps providing nutrients) as preferred production areas, are accounted for by vertical motions in subduction zone evolution