Influence of past and present-day plate motions on spherical models of mantle convection: implications for mantle plumes and hotspots     

Sandrine Quéré  Alessandro M. Forte 《Geophysical Journal International》2006,165(3):1041-1057

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Field investigations and monitoring as tools for modelling the Rossena castle landslide (Northern Appennines, Italy)     

Alessandro Chelli  Giuseppe Mandrone  Giovanni Truffelli 《Landslides》2006,3(3):252-259

In the evening of February 28, 2004, a landslide took place in the village of Rossena (Northern Apennines, Italy), built at the base of a crag shaped in a basalt mass and wrapped in highly deformed formation of clay and shale with blocks. The failure damaged some houses, roads and fields but, fortunately, the medieval Rossena Castle, lying on the crag, was not involved at all. The goal of the study was to attain a technical and geological model of the slope to generate a landslide risk zonation, for regularity and development planning, so that the most correct action plans could be proposed. A detailed geological and geomorphological survey allowed for distinguishing the different gravitative landform of this area. It was very helpful to plan direct and indirect investigation, including borehole drillings, samplings, seismic (tomography), and electrical surveys. A monitoring system was built up immediately after the event (three wire extensometers and one inclinometer), then progressively substituted by a more complete one (two tiltmeters, two jointmeters, four inclinometers, two incremental extensometers, and two piezometers). The phenomenon can be divided in different parts. The central sector of the slope is interested by compound slides likely affecting the bedrock and can be considered, at present, the ‘engine’ of the whole instability framework. Indeed, as a consequence, in the upper portion of the slope the huge blocks in which the outer part of the crag is disjointed experienced vertical displacements and, locally, topplings. Finally, the lowest sector is affected by slow movements, probably connected to bedrock creep or rock flow, while the toe, really at the foot of the slope, by shallow landslides. This instability framework is the result of a complex evolution, starting almost more than 9,000 years ago, as testified from a radiocarbon dating. In more recent time (19th century), the Rossena landslide was also triggered by an earthquake that induced the partially breaking up of the crag, causing rock falls and cracks in the ground.  相似文献   

An Overview on the Kuiper Belt and on the Origin of Jupiter-family Comets     

Alessandro Morbidelli 《Celestial Mechanics and Dynamical Astronomy》1998,72(1-2):129-156

The present paper reviews our current understanding of the dynamical structure of the Kuiper belt and of the origin of Jupiter-family comets. It also discusses the evolutionary scenarios that have been proposed so far to explain the observed structure of the Kuiper belt population. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Tectonic structure and post-Hercynian evolution of the Serre, Calabrian Arc, southern Italy: Geological, petrological and radiometric evidences     

Aldo Del Moro  Antonio Paglionico  Giuseppe Piccarreta  Alessandro Rottura 《Tectonophysics》1986,124(3-4)

Conflicting opinions exist concerning the structure and the post-Hercynian evolution of the Serre. The present paper deals with these topics on the basis of new geological, petrological and radiometric evidence. The composition of the so-called Stilo and Polia-Copanello units has been redefined. The above domains—former sections of upper and lower Palaeozoic continental crust respectively—came into contact, due to transcurrent movements 130–140 Ma ago. A significant vertical component during the transcurrent movements, probably, exhumed the former section of lower crust. The above domains, juxtaposed, were successively involved as a single kinematic body in the Alpine orogenesis. The results enable us to make inferences for the Calabrian Arc evolution and call attention to similarities between an Austro-Alpine element (Stilo + Polia-Copanello) of the Calabrian chain and a South-Alpine sector of the Alps (Ivrea + Ceneri zones).  相似文献   

The equilibrium form of a rotating earth with an elastic shell     

Jon E. Mound  Jerry X. Mitrovica  Alessandro M. Forte 《Geophysical Journal International》2003,152(1):237-241

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Average strain rate in the Italian crust inferred from a permanent GPS network – I. Statistical analysis of the time-series of permanent GPS stations     

Alessandro Caporali 《Geophysical Journal International》2003,155(1):241-253

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Late Triassic-Early Jurassic Paleokarst from the Ligurian Alps and its geological significance (Siderolitico Auct., Ligurian Briançonnais domain)     

Alessandro Decarlis  Alberto Lualdi 《Swiss Journal of Geoscience》2008,101(3):579-593

In the Ligurian Briançonnais domain, the thick Middle Triassic carbonateplatform units, formally known as the Costa Losera Fm. and S. Pietro dei Monti Dolomites, are followed by a significant unconformity separating them from the Rio di Nava neritic limestones of Bathonian age. According to the evolution of a passive continental margin, the end of subsidence and subsequent uplift led to the progressive erosion of the Triassic carbonate platform from outer to inner units, i.e., in the direction of the Ligurian Tethys. This erosion, possibly acting on a fault-controlled block system, created sedimentary sequences of differential composition, and the virtual absence of the entire Triassic complex and even the underlying Permian rocks. In the study area (and in many other locations belonging to the external Ormea unit), the so-called “briançonnais sedimentary gap” shows more than a nondepositional surface: the associated deposits (known as “Siderolitico” Auct.) include both red pelites between the above-mentioned units, and deep-penetrating karstic red breccia within the Ladinian carbonates. We performed detailed stratigraphic, microfacies and compositional analyses on the karsts and paleosoils associated with the unconformity in order to define their character, genesis and age. In addition, we discuss the regional context and importance of these deposits in a large-scale comparison with the classic Briançonnais domain and other locations of the Western Alpine Arch with the same unconformity. In light of these data, we propose an Upper Triassic to Early Jurassic age (until the Upper Bajocian?) for the karstic event in the Ligurian Alps.  相似文献   

Effects of basement structural and stratigraphic heritages on volcano behaviour and implications for human activities （the IGCP project 455）     

Alessandro Tibaldi Alfredo Mahar F. A. Lagmaye Vera V. Ponomareva 《《幕》》2005,28(3):158-170

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Post‐Variscan tectonics in eastern Anti‐Atlas (Morocco)     

Marco G. Malus  Riccardo Polino  Andrea Cerrina Feroni  Alessandro Ellero  Giuseppe Ottria  Lahssen Baidder  Giovanni Musumeci 《地学学报》2007,19(6):481-489

New field data integrated by fission‐track (FT) analysis unravel an innovative scenario for the post‐Variscan evolution of the eastern Anti‐Atlas. This area, unaffected by Meso‐Cenozoic tectonics according to most workers, is crosscut by crustal faults bearing evidence of a polyphase deformation history. Apatite FT ages, ranging between 284 and 88 Ma, point to fast Neogene exhumation and unravel contrasting cooling paths across major faults. Results show that the study area was buried beneath 2 km of allochthonous Variscan units, now eroded. The eastern Anti‐Atlas acted as the southern shoulder of the Atlasic rift in the Mesozoic, and underwent a dextral transpressional structuring of Neogene age followed by sub‐meridian shortening. The southern front of Atlasic deformation is therefore located inside the Anti‐Atlas region, and it is still active.  相似文献   

On the dynamics in the asteroids belt. Part II: Detailed study of the main resonances     

Alessandro Morbidelli  Antonio Giorgilli 《Celestial Mechanics and Dynamical Astronomy》1989,47(2):173-204

The general theory exposed in the first part of this paper is applied to the following resonances with Jupiter's motion : 3/2, 2/1, 5/2, 3/1, 7/2, 4/1; these are the most relevant resonances for the asteroids. The whole analysis is performed in the framework of the spatial problem of three bodies, both in the circular and in the elliptic case. The results are also compared with the observed distribution of the asteroids.  相似文献