1,721,007 research outputs found
geologia quantitativa e morfotettonica dell'area di Morlupo-Castelnuovo di Porto nei Monti sabatini (Lazio)
No full textStudio geomorfologico delle depressioni vulcaniche di Sacrofano e di baccano nei Monti sabatini
No full textContributo dell’analisi geomorfica quantitativa allo studio dei processi di denudazione nel bacino idrografico del F. Paglia (Toscana meridionale-Lazio settentrionale).
No full textMorphological analysis and erosion rate evaluation in badlands of Radicofani area (Southern Tuscany-Italy)
No full textSince 1988, geomorphologic research based on field surveys and photo-geological analysis, has been conducted in southern Tuscany (Italy), in areas characterised by very rapid morphological evolution. In the area outcrop Pliocene marine claystones uplifted during the Quaternary up to 750 m above sea level, now undergoing intense erosion processes, leading to considerable badlands formation. Morphodynamic analysis, conduced by direct and indirect measurements in a sample area, were taken in order to quantify the erosion rate in badland areas. The “Torrente Piantrafolla” sample area was chosen as representative of the study area; it was most recently monitored during the period Nov. 2000–Feb. 2004. At this time, morphographic and morphometric analyses carried out in selected measurement stations located on slopes, identified gravity as the main morphogenetic process responsible for slope shaping. The calanchi badland areas are characterised by constant and rapid shrinking of their edges resulting from landslides which occur in autumn and winter as a consequence of intense rainstorms. Selected measurement stations indicate an erosion rate value range from 5 to 7.5 cm/y. The comparison between 1976 and 1994 digital elevation models (DEM), obtained from photogrammetric restitution, indicated a mean erosion rate of about 5 cm/y in a nineteen year period. This value, considerably higher than the values measured in other Italian basins, indicate a very rapid evolution of the slopes, due mainly to small earth flows inside calanchi badlands
The extent of Pleistocene glaciations in the western part of the Campo Imperatore (Gran Sasso Massif, Central Italy)
No full textThe paper reports some major geomorphologic features of the western part of the tecnotics depression of the Campo Imperatore (Gran Sasso Massif, Abruzzo Region, Italy). Represents a specific and very fine example of glaciated mountain landscape, where landforms typical of glacial erosion are commonplace over 1,800 m a.s.l
Geomorphological evolution and neotectonics of the Sulmona intramontane Basin (Abruzzi, Apennine, Central Italy).
No full textGeomorphologic features and radiocarbon dating of some quaternary deposits at Difesella del Trionto (Calabria, southern Italy).
No full textThe sedimentary deposits, Pleistocene in age, outcropping at Difesella del Trionto (Calabria) are examined. The main geologic and morphologic characters, along with the results of radiocarbon dating and organic geochemical analysis of some layer rich in organic carbon are reported. The results, strongly suggesting thet about 31,000 yr. B.P. a lake formed in the area, are in line with landsliding events which occurred downvalley of Difesella, as it is recorded by several morphologic feature. It is inferred that such processes triggered the valley damming. thus determining lacustrine sedimentation
Morphodynamics and morphological changes of the last 50 years in a badland sample area of Southern Tuscany (Italy)
No full textThe purpose of this geomorphologic study was to analyse thc recent morphologic evolution of calanchi badlands over a SO years' period (1955-2006) and to evaluate the mean
erosion rate in areas situated in Southern Tuscany. These areas are characterised by Pliocene marine claystone which have undergone and continue to undergo erosion processes and a rapid morphologic evolution. Our morphodynamic investigation was based on systematic field surveys conducted over a 12 years' period (1994-2006) and photogeological analysis of a 30 km2 wide area. The systematic field surveys demonstrated that in the calanchi badland areas, erosion processes due to sheet-wash and channelled water act together gravitational processes, mainly represented by landslides and solifluction. Our research indicated that the effects of gravitational processes have increased over the last 10 years while sheet-wash action has been less intense over that same period. This is demonstrated by the progressive increase of flows at
the top of the calanchi badland slopes which determined the general rounding of sharp crests and the partial filling of several cuttings. In addition, our morphodynamic analys is strongly
suggests that anthropogenic action should not be overlooked or underestimated as a major force in shaping the landscape in the study area over the last so years. Quantitative evaluation
of the morphodynamic evolution based over a 50 years' period, was carried out in the "Torrente Cacarello" sample area, chosen as representative of the whole study area. The comparison
between 1955, 1976 and 2006 detailed geomorphologic maps (scale 1 :5,000), obtained from the aerial photographs and from the recent (2006) field survey, allowed us to estimate the
morphological differences which occurred in this period. Detailed analysis of the three geomorphological maps of the sample area obtained for eaeh peri od, were compared through a GIS software and enabled us to quantify the following different morphological processes that influenced the variation found in these areas: 1) the calanchi badland area increased over the
last 50 years; 2) mass movements prevail over sheet wash erosion; 3) calanchi badlands in their most recent morphological state are shaped by numerous scattered small landslides.
The geomorphological study in the sample area was completed by direct morphodynamic analysis: measurements of erosion were taken in order to quantify the mean erosion rate.
The sample area was monitored during the period JuI. OO-Jan. 06. Morphographic and morphometric analyses showed that the calanchi badlands are characterised by constant and quick shrinking of their edges eaused by landslides. Selected measurement stations located on slopes indicated an erosion rate ranging from 6 to 6.5 cm/y. The mean erosion rate measured in the sample area of this study was comparable to the mean crosion rate indicated in our earlier studies of neighbouring areas of Southern Tuscany; the mean erosion rate in both of these studies was significantly higher than those indicated by other authors who have studied ltalian badlands
Geomorphological features of Monte Vulture Pleistocene volcano (Basilicata, Southern Italy).
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