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Deep-seated gravitational slope deformations near the Abetone Pass (Tuscan-Emilian Apennines)
No full textGeomorfologia delle valli del Rio delle Pozze e del Torrente Motte (Abetone, Appennino Tosco-Emiliano).
No full textAn accurate knowledge of present and past geomorphological processes in an area of the Tuscan-Emilian Apennines near Abetone was achieved in this study, also by elaborating a geomorphological map at a 1:10,000 scale. In this territory, prevalently characterised by arenaceous rock types and, secondarily, by argillaceous and silty ones, the landforms listed below were recognised.- Structural landforms: the most evident are located near the mountain crest, where the slope face corresponds to the stratum surface of the Macigno Sandstones and where there are structural scarps more than 30 m high.- Glacial landforms and deposits: they include cirques, overdeepened hollows, roches moutonnées and moraine ridges.- Cryogenic and nivation landforms and deposits: among these, block fields, nivation hollows, avalanche tracks and cones, protalus ramparts, block streams and gelifluction deposits should be mentioned.- Gravity-induced slope landforms and processes: besides the presence of particularly developed scree slopes, various types of mass movements have been recognised, such as earthflows, falls and topples, translational slides, rotational and roto-translational slides, as well as deep-seated gravitational slope deformations (Dgsd), the latter characterised by a dominant structural control (NW-SE and SW-NE oriented faults).- Landforms, processes and deposits due to running waters: slopes affected by rill wash, colluvial and alluvial fans, related to concentrated running waters, are present together with swampy deposits filling small structural depressions; moreover, two orders of alluvial terraces, badland forms, debris flows and small waterfalls have been surveyed. Since the hydrographic network is in a deepening stage, present alluvial deposits are found only upstream of the numerous wiers that dam the courses of the Pozze and Motte torrents.- Anthropogenetic landforms and deposits: among Man's activities which modify the landscape, the construction of large parking areas and ski pistes should be mentioned; these kinds of activities have produced slope cuts and filling of some small swampy areas.The data acquired allowed geomorphological events to be reconstructed starting from late Upper Pleistocene. In particular, in this sector of the Northern Apennines glacial traces ascribable only to the glaciation known in the Alps as Würm III were found. An attempt to reconstruct a relative chronology of the stadial phases was also carried out, thus identifying forms related to Apennines Stage I, which was characterised by two distinct stages with snow limits respectively of 1,611 and 1,663 m a.s.l., and Apennines Stage II, also characterised by two phases with a snow limit ranging between 1,770 and 1,836 m. Apennines Stage III did not leave any trace since, according to the previous authors, its permanent snow limit would be found at heights superior to those of the Apennine peaks of this area.In general, the action of the various morphogenetic agents in the evolutive history of these valleys was strictly conditioned by the structural characteristics of the area
Gravitational slope deformations near the Abetone Pass (Tuscan-Emilian Apennines)
No full textIn this paper some Deep-seated Gravitational Slope Deformations (Dgsd), identified in the Rio delle Pozze valley near the Abetone Pass, are for the first time described. These deformations are developed in competent rock types (sandstones layers with argillite intercalations belonging to the Macigno Formation) and are characterised by a dominant structural control (NW-SE and SW-NE oriented faults). From the geomorphological viewpoint they show double ridges, trenches, concavities and reverse slopes. The Dgsd typologies correspond to rock flows (Sackungen). On the eastern slope of Monte Gomito (located in the adjacent Torrente Motte valley) the same geomorphological features shown by the Rio delle Pozze valley Dgsd have been surveyed. These landforms, which were analysed with respect to the structural characteristics of the zone, are here considered as the surface expression of an incipient rock slide. It is therefore an example of 'geomorphological convergence' within the framework of slope gravitational processes
Geomorfologia delle Valli del Rio delle Pozze e del Torrente Motte (Abetone, Appennino Tosco-Emiliano)
No full textGlacial features in the Tuscan-Emilian Apennines (Italy). Evidences from the Abetone area.
No full textThe highest peaks of the Tuscan-Emilian Apennines often show ancient glacial landforms and deposits, among which cirques, moraine ridges, overdeepned hollows, roches moutonnée and striations are represented. In this paper, the fundamental traces of the last glaciations in the Abetone area are synthetically illustrated. The data acquired in time by many Authors allowed glacial chronology to be reconstructed, starting from late Upper Pleistocene. As regards the Abetone area (Rio delle Pozze and Torrente Motte valleys), glacial traces referable only to the Alpine Würm III were recognized. In this area, an attempt to reconstruct a relative chronology of the stadial phases identified forms related to Apennines Stages I and II. On the contrary, the Apennines Stage III did not leave any trace, since its permanent snow limit would be found at heights superior to those of the peaks of this area. ), The lack of traces of glacial periods older than the Würm may be explained with the hypothesis that they could be obliterated by erosional processes linked to the considerable uplift of this sector occurring from the Middle-Upper Pleistocene and continuing to date
La catastrofe idrogeologica del 19/6/1996 in Versilia e Garfagnana (Toscana, Italia): aspetti geomorfologici e valutazioni idrauliche
No full textThe June 19, 1996 hydrogeological catastrophe in Versilia and Garfagnana (Tuscany, Italy): geomorphological aspects and hydraulic evaluation. The rainfall that occurred in Versilia and part of Garfagnana on June 19, 1996 was exceptionally heavy: the 13 hour rain attained 478 mm in Alta Versilia and 420 mm in Garfagnana (in the basin of the Versilia River, the average rain per year is 1430 mm). The valleys of the Vezza River in Alta Versilia and of the Turrite di Gallicano Stream in Garfagnana were the most affected. The greatest damages were suffered by villages in the valley bottoms: Cardoso (nearly destroyed) and Fornovolasco (partially destroyed). Several landslides invaded the main and secondary roads, also taking away long stretches of them. The consequences of the flood were remarkable in the plain too: the Versilia River, which originates from the union of the Vezza River with the Serra Stream just before it flows into the plain, broke its left bank for about 70 m in correspondence with an artificial bight (the deviation was made some centuries ago to drain the Porta Lake), overflowing in a heavily populated area, flooding 8 km2 and breaking off the Aurelia highway and the Roma-Genova railway. The features of the landslides are related to the geologic, lithologic and morphologic parameters of the slopes. As for the plain, frequently flooded by the Versilia River, we attempted a calculation of the high flows with assigned return period; from the examination of the results, it appears that the flow rate capable of making overflows have a return period shorter than 10 years. Intensive measures are suggested to prevent catastrophic events, both in the plain and in the mountainous region
La catastrofe idrogeologica del 19/6/1996 in Versilia e Garfagnana (Toscana, Italia): aspetti geomorfologici e valutazioni idrauliche
No full textGlacial features in the Tuscan-Emilian Apennines (Italy): evidence from the Abetone area
No full textThe highest peaks of the Tuscan-Emilian Apennines often show ancient glacial landforms and deposits, among which cirques, moraine ridges, overdeepned hollows, roches moutonnée and striations are represented. In this paper, the main traces of the last glaciations in the Abetone area are synthetically described. The data acquired in time by many Authors allowed glacial chronology to be reconstructed, starting from late Upper Pleistocene. As regards the Abetone area (Rio delle Pozze and Torrente Motte valleys), glacial traces referable only to the Alpine Würm III were recognized. In this area, an attempt to reconstruct the relative chronology of the stadial phases identified forms related to Apennines Stages I and II. On the contrary, the Apennines Stage III did not leave any trace, since its permanent snow limit would higher than the peaks of this area. The lack of traces of glacial periods older than the Würm may be explained with the hypothesis that they could be obliterated by erosional processes linked to the considerable uplift of this sector occurring from the Mid-Upper Pleistocene and continuing today
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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