1,721,185 research outputs found
Petrographical and geochemical characterization of Messinian carbonate facies in Tertiary Piedmont basin : constrains for late Miocene evolution of NW Italy
No full textCavagna Simona, Clari Pier Angelo, Dela Pierre Francesco, Irace Andrea, Festa Andrea. Petrographical and geochemical characterization of Messinian carbonate facies in Tertiary Piedmont basin : constrains for late Miocene evolution of NW Italy. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. pp. 66-67
The Moncucco quarry : a key area to understand the Messinian evolution of the Torino Hill, tertiary Piemonte Basin, NW-Italy
No full textIrace Andrea, Clari Pier Angelo, Dela Pierre Francesco, Bicchi Erica, Cavagna Simona, Festa Andrea. The Moncucco quarry : a key area to understand the Messinian evolution of the Torino Hill, tertiary Piemonte Basin, NW-Italy. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. pp. 131-132
Role of folding-related deformation in the seismicity of shallow accretionary prisms
No full text{The sources of shallow slow earthquakes at subduction zone fronts remain unclear, but are commonly attributed to faults and shear zones. Structural studies of modern and ancient shallow accretionary prisms — wedge-shaped stacks of sediments and volcanic deposits scraped from subducting slabs and accreted onto the overriding plates at convergent plate boundaries — document a plethora of brittle structures associated with metres to plurikilometre-scale overturned and recumbent folds. These folds are the product of rock buckling and shearing at the front of subduction zones. At present, such structures are not commonly considered in models of the dynamics of accretionary wedges at the timescale of the seismic cycle, instead focusing on the role played by slip on major faults. Here we argue that fold-related brittle structures might also be associated with transient deformation events at elevated strain rates and in the presence of high fluid pressure. They have the potential to cause distributed microearthquake swarms occurring under low effective normal stress in accretionary prisms, and to affect the distribution of surficial displacement. Folding-related brittle deformation structures in accretionary wedges may contribute to shallow seismicity in subduction zones, according to a compilation of structural evidence.
Offscraping and shallow ophiolite accretion in the Ligurian Accretionary Wedge (Tuscan Apennines): role of seafloor structural inheritance
No full textRedefinition of the Ligurian Units at the Alps–Apennines junction (NW Italy) and their role in the evolution of the Ligurian accretionary wedge: constraints from mélanges and broken formations
No full textWe document that the undifferentiated chaotic Ligurian Units of the Monferrato–Torino Hill sector (MO-TH) at the Alps–Apennines junction consist of three different units that are comparable with the Cassio, Caio and Sporno Units of the External Ligurian Units of the Northern Apennines. Their internal stratigraphy reflects the character of units deposited in an ocean–continent transition (OCT) zone between the northwestern termination of the Ligurian–Piedmont oceanic basin and the thinned passive margin of Adria microcontinent. The inherited wedge-shaped architecture of this OCT, which gradually closed toward the north in the present-day Canavese Zone, controlled the Late Cretaceous–early Eocene flysch deposition at the trench of the External Ligurian accretionary wedge during the oblique subduction. This favoured the formation of an accretionary wedge increasing in thickness and elevation toward the SE, from the MO-TH to the Emilia Northern Apennines. Our results therefore provide significant information on both the palaeogeographical reconstruction of the northwestern termination of the Ligurian–Piedmont oceanic basin and the role played by inherited along-strike variations (stratigraphy, structural architecture and morphology) of OCT zones in controlling subduction–accretionary processes
Structural constraints on the subduction of mass transport deposits in convergent margins
Full text linkThe subduction of large and heterogeneous mass-transport deposits (MTDs) is discussed to modify the structure and physical state of the plate boundary and therewith exert an influence on seismicity in convergent margins. Understanding which subduction-zone architectures and structural boundary conditions favour the subduction of MTDs, primarily deposited in oceanic trenches, is therefore highly significant. We use bathymetric and seismic reflection data from modern convergent margins to show that a large landslide volume and long runout, in concert with thin trench sediments, increase the chances for an MTD to become subducted. In regions where the plate boundary develops within the upper plate or at its base (non-accretionary margins), and in little-sedimented trenches (sediment thickness 4 km) and short runout, an MTD will only be subducted if the thickness of subducting sediments is higher than the thickness of sediments under the MTD. The results allow identification of convergent margins where MTDs are preferentially subducted and thus potentially alter plate-boundary seismicity
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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