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Antarctic/Scotia plate convergence off southernmost Chile
Full text linkThe southern tip of South America off Chile has suffered a long phase of ocean-continent convergence which has shaped the continental margin through different phases of accretion and tectonic erosion. The present accretionary wedge is a discontinuous geological record of plate convergence and records only part of the accretionary processes resumed after Chile ridge consumption (14 Ma). The structural style of the subduction complex, such as rates of sediment accretion and tectonic erosion, structural vergence, width of the accretionary wedge, taper angle and deformation in the forearc basin, varies along the margin. Large taper values are related to narrow wedges and seaward vergent structures. Low tapers occur where deformation at the toe of the accretionary complex is spread over wide areas and is related both to landward and seaward vergent thrust faults. Seismic data interpretation contributes to define more accurately frontal wedge morphology and geometry of subduction and suggests that different modes of accretion together with tectonic erosion may be active concurrently along the trench at different locations. In areas of subduction driven accretionary processes the majority of trench sediments are involved in accretionary processes and sediments are uplifted and piled up in the form of imbricate thrust sheets. In areas where the wedge is non-accretionary the continental margin shows steeper continental slopes associated with narrow accretionary wedges, more intense sediment disruption and very shallow décollement levels. Variation in structural style and in the geometry of the forearc region setting off Southernmost Chile, has been interpreted as related to the existence of different structural domains: the nature of their boundaries is still unclear mainly for the lack of high resolution bathymetric data. They have been tentatively related to tectonic lineaments belonging to the Magellan Fault system and/or to the character and morphology of the converging plates (lateral heterogeneities, sea-mounts and fracture zones), which produce a segmentation of the margin
Oblique subduction along the southernmost Chile Trench: Varying rates of sediment accretion and tectonic erosion driven by margin segmentation
No full textThe accretionary complex of southernmost Chile from the analysis of multichannel seismic data
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THE DEEP SEA RECORD OF LARGE EARTHQUAKES IN THE MEDITERRANEAN SEA: THE CALABRIAN ARC SUBDUCTION COMPLEX
No full textReply The lifecycle of sub-continental peridotites: From rifted continental margins to mountains via subduction processes
No full textReply to https://doi.org/10.1130/G48665C.1 (Comment by Andrea Argnani
Relationships between recent tectonic activity, mud diapirism and slope instability in the Gulf of Squillace (Calabrian Arc, Ionian Sea)
No full textModelling tectonic deformation along the North-Anatolian Fault in the Sea of Marmara
Full text linkUsing analogue techniques, we attempted to model the complex tectonic deformation pattern observed along the North-Anatolian Fault in the Sea of Marmara from morpho-bathymetry and seismic reflection images. In particular this paper focuses on the so-called Cinarcik segment of the fault connecting the eastern Izmit segment, which entirely ruptured during the Mw 7.4, 1999 earthquake, to the western segment of the Central High. The Çınarcık segment, potentially loaded after the Izmit earthquake, is expected to rupture during an earthquake occurring in the near future, possibly the next decades, with a high potential to affect the Istanbul metropolitan area. Our analysis suggests that the development of the observed structures accommodating strike-slip, transtensional and transpressional deformations, could be explained by changes in the geometry of fault segments within a right-lateral strike-slip tectonic regime. Tectonic deformations were reproduced in the analogue model by imposing a small (about 10°) and sharp difference in the relative orientations of the strike-slip segments at the edges of a major releasing bend. In the model slower strain accumulation occurs along the analogue of the Çınarcık segment than along the analogue of the Izmit segment of the fault. This would predict a delay for earthquakes triggered by stress transfer between the Izmit and Çınarcık segments. The model further predicts that most of the deformation in the Çınarcık basin is controlled by the sharp changes in the geometry of the fault itself
Deep structure and historical earthquakes in the Calabrian subduction zone (Southern Italy)
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