1,721,203 research outputs found
Carta geomorfologica della V. Miller e della Conca del Baitone (Gruppo dell'Adamello, Brescia). Alla scala di 1:15.000, con note illustrative. Geomorphological map of the Val Miller and the Baitone area (Adamello Group, Brescia).
No full textMagmatic intrusive
rocks (Western Adamello Tonalite, diorite and gabrodiorite, with related dykes) outcrop in this region.
Contact metamorphic rocks are also known from the Baitone area.
The present physionomy ofthe valley is related to various morphogenetic agents. Those that acted for a longer
time and more deeply are the glacial and periglacial ones. Typical erosional and depositional glacial forms are
present all over the region. On the basis of morphological, stratigraphical, textural observations and of the
weathering ofthe deposits as well as the degree oflichenization and the soil development, the Authors tried to
differenziate the various glacial deposits. The last century moraines and those ofthe Late Pleistocene are easy
to distinguish. Landforms related to periglacial environments such as rock-glaciers, protalus ramparts, avalanche
tracks and cones have been recognized. Recent debris-flow lobes are present in the Malga Valley resting
on stabilized debris and dejection cones
Metodi e materiali per lo studio dei ghiacciai
No full textI ghiacciai rappresentano un componente essenziale per l’ecosistema, fungendo da riserva d’acqua dolce e sostenendo la biodiversità. Il loro rapido arretramento, in tempi recenti, ha importanti conseguenze per l’equilibrio ambientale. Il volume esplora il mondo del ghiaccio e dei ghiacciai in Trentino considerandoli come ampi ecosistemi di alta quota e analizzando la loro evoluzione nel tempo. L’opera racconta la storia di questi ambienti unici analizzando la loro morfologia, incluse le forme più nascoste, celate nel sottosuolo, e quella delle zone circostanti. Il testo, arricchito da mappe storiche, rilievi cartografici recenti ed eloquenti confronti fotografici fra passato e presente, si intreccia con il racconto delle prime esplorazioni alpinistiche e con storie di uomini e donne che sui ghiacciai hanno vissuto e combattuto. Particolare attenzione viene posta alle dinamiche di questi ecosistemi, alla loro fragilità e alle implicazioni ecologiche legate agli effetti dei cambiamenti climatici. Un viaggio che, attraverso le mutazioni della natura, invita a riflettere sulla relazione tra il nostro futuro e il destino delle montagn
Geomorfologia dell'alta V. di Genova (Gruppo dell'Adamello, Alpi Centrali). Con allegata carta geomorfologica alla scala di 1:15.000
No full textThe Val di Genova is one of the most characteristic valleys of the Adamello Group. It extends up to the Adamello and Lobbia-Fumo summit glaciers, two high plateau glaciers which follow, with their relative effluences, the valleys radiating out from the summit area. Other smaller glaciers and snowfields develop in small cirques and other topographically protected areas. The morphogenetic agents which have been most influential are glacial and periglacial, still active at the glacier edges. There are also landorms and deposits clearly associated with gravity and with the flow of fluvial and fluvioglacial waters, which are active, together with phenomena of debris flow which occurred towards the end of the 1980s, in the lower part of the valley. On the basis of morphological, sedimentological, stratigraphic, lichenometric and dendrochronological observations and with the help of severl 14C dates, preminent phases of the geomorphological evolution of the study area were constructred. The maximum extension in the Holocene of the Vendretta della Lobbia and Vedretta del Mandrone were reconstructed and some moraines associated with different events in the Little Ice Age were dated. In particular, a moraine near M.ga Matarot shows an advance of the Vedretta della Lobbia ascribed to the first phases of the Little Ice Age and dated at around 410±90 years 14C BP (1430-1635 AD). Since the middle of the last century there has been a notable regression of the glaciers, broken by brief and not very marked advances, however not always registered accordingly by the main glaciers. The evident contraction of the ice surface has brought about a lowering of the surface of the ice by several tens of meters in the accumulation area and the marked regression of the fronts has caused a withdrawal of more than 2000 m for the Vedretta della Lobbia and about 1800 m for the Vedretta del Mandrone
Geomorfologia della Valle dell’Avio (Gruppo dell’Adamello). Con allegata carta geomorfologica alla scala 1:15.000. Geomorphology ofAvio Valley (Adamello Group). With an original geomorphological map at the scale of 1:15,000
No full textThe authors have carried out an investigation that led to the production of a geomorphological map and its
related explanatory notes. The present physionomy of the valley, mainly consisting of intrusive magmatic
lithotypes, is related to various morphogenetic agents: those that acted for a longer time and more deeply
are the glacial and periglacial ones. Typical erosional and depositional glacial forms characterize the middle
and high valley. Morphological, stratigraphical and textural observations regarding. the weathered state of
the deposits and the degree of lichenization, the various morainic deposits have been tentatively differentiated.
The moraines from the last century are particulary abundant and thickly developed; in some places they
cover deposits probably "ascribable to older stages of the «small glaciation». Also the moraines ascribable to
the late-glacial stages are widely represented. Landforms related to periglacial environments such as rockglaciers,
protalus rampart, etc., have been recognized. Particular landforms related to gravity and favoured
by the metamorphic- type substratum are recognizable in the lower valley
Variazioni oloceniche della Vedretta della Lobbia (Gruppo dell'Adamello, Alpi Centrali). Holocene variations of the Vedretta della Lobbia (Adamello Group, Central Alps).
No full textGeomorphological, glacial geological, lichenometrical and dendrochronological
studies have been carried on the Upper Val di Genova
with the aim of reconstructing Holocene fluctuations of the Vedretta
della Lobbia.
Some moraines have been dated on the basis of iconographical documents
and dendrochronological studies. This allowed the reconstruction
of two lichenometrical curves for the groups Rbizocarpon geographicum
and Aspicilia cinerea for the period 1864-1915 A.D . The growth
rates are respectively, 0,5 mm/yr and 1,7 mm/yr. The Larch colonisation
times has been evalued at about 15 years .
The maximum extention reached by the glacier during the Little
Ice Age is marked by a moraine near the Malga Matarot bassa, at about
1 790 m. The age of this moraine is comprised between 1645 A.D.
and 1845 A.D.
The maximum position of the same glacier during the Holocene
has been determined at a slightly more advanced point (before
5310 ± 180 14C years B.P .).
An end moraine located about 100 m South of the Malga Matarot
bassa, at about 1 790 m, marks the position reached by the glacier in
the second half of the last Century. In the 20th Century, the Vedretta
della Lobbia gradually retreated to its present position at about 2 570
m. Small phases of advance (or stability) have been identified through
some moraines dating back the early 1890's and 1920's. The total
retreat, between 1864 and the present has been estimated at over 2 000
m. When the glacier was at its maximum position during the Little
Ice Age, the snowline was situated about 60 m below the present
snowline (2 950)
Vedretta di Pisgana (Gruppo dell'Adamello). Geomorfologia e variazioni oloceniche della fronte. Con allegata carta geomorfologica alla scala 1:15.000. Vedretta of Pisgana (Adamello Group). Geomorphology and Holocene front variations.
No full textVedretta of Pisgana (Adamello Group). Geomorphology and Holocene front variations.
The Vedretta of Pisgana is located in the upper Narcanello Valley and it terminates with three distinct
fronts. The western tongue is the best developed and it deposited several moraines which document Holocene
front variations. Late Glacial and Holocene moraines of the Narcanello Valley have been differentiated
on the basis of morphological, stratigraphical, textural observations, 14C dates and of the weathering
degree of the glacial deposits as well as lichenization and soil development. From the left side of
Narcanello Valley comes the oldest 14C date so far obtained in the Adamello Group. A buried soil found
at 2545 m a.s.l. between two lateral moraines, Late Glacial and Holocene respectively, yielded an age
of 6600 ± 100 14C yr BP (GX-14711). In the same area two dates bracket a Neoglacial advance of
the western portion of the Vedretta of Pisgana. The maximum- limiting age is 3015 ± 75 14C 1/ BP
(GX-14712), while the minimum- limiting age for the Pisgana glacier advance is 2345 ± 125 4C yr
BP (GX-14710). The western portion of the Vedretta of Pisgana retreated about 1000 m since the first
years of the XX Century. Three small advances also occurred, the widest between 1939 and 1941 (about
40 m). A geomorphological map of the upper Narcanello Valley completes this note
The Adamello-Presanella and Brenta Massifs, Central Alps: Contrasting High-Mountain Landscapes and Landforms
No full textAdamello-Presanella and Brenta massifs are two distinct and adjacent mountain groups divided by an Alpine structural alignment which separates the Southern Alps into two distinct blocks characterized by different rock types. The Adamello-Presanella Massif is made up of intrusive igneous rocks and shows typical landscapes of high-mountain environments modelled prevalently by the action of glaciers. In the Brenta Massif limestones and dolostones crop out extensively which have been shaped into steeples, pinnacles, vertical rock faces and ledges by selective erosion. In this mountain group subsurface and surface karst landscapes have also developed. Owing to its extraordinary interest and geological-geomorphological value, these massifs are included in the European Geoparks Network and in the World Global UNESCO Network of Geoparks
Variazioni glaciali oloceniche nel Gruppo del M. Adamello. Holocene glacial variations in the Adamello Group.
No full textStudies about glacial geology and geomorphology
of the Adamello Group have been carried out in
recent years with particular attention to Holocene
landforms and deposits. Till now the following valleys
have been investigated: V. dell'Avio, V. Miller - Conca
del Baitone, V. Narcanello and upper V. di Genova.
Of the 20 glaciers present in the studied area, the Pisgana,
Lobbia and Mandrone glaciers proved to be of
particular interest. These are between the widest
glaciers of the group and are all systems with northerm
exposures. Late Pleistocene and Holocene tills
have been differentiated on the basis of the sedimentological
characters, lichen cover and development of
soils, as well as weathering degree. Several Holocene
moraines have also been identified.
Several 14C dates were obtained from buried soils
and peat in V. Narcanello and V. di Genova. The oldest date so far obtained in the Adamello Group is
from the left side of V. Narcanello. A buried soil
found at 2545 m a.s.I, between two lateral moraines,
Late Glacial and Holocene respectively yielded an age
of 6600 ± 100 14C yr BP (GX-14711) corresponding to
7569/7372 cal yr BP (according to STUIVER & REIMER,
1986).
In the same area, at about 2470 m, two buried
soils yielded dates bracketing a Neoglacial advance of
the Pisgana Glacier. The first sample was dated to
3015 ± 75 14C yr BP (GX-14712) corresponding to
3350/3086 cal yr BP (maximum limiting age). It was
collected from a soil developed on the cited Late Glacial
moraine at about 2470 m and buried by a
Holocene lateral moraine. The minimum limiting age
for the Pigsana glacier advance was supplied by a soil
buried in a depression at about 2600 m and supported
by the same lateral moraine. It was dated to
2345 ± 125 14C yr BP (GX-14710), corresponding to
2706/2207 cal yr BP.
In V. di Genova an end moraine deposited at
about 1775 m a.s.I. supports a peat deposit, the base
of which was dated to 5310 ± 180 1 C yr BP (GX-15319).
It supplies a minimum limiting age for the
moraine, probably of Holocene age. Calibrated according
to STUIVER et alii (1986) the age is 6299/5919
yr BP.· The top of the same peat deposit directly underlies
another end moraine. It produced an age of
1190 ± 75 14C yr BP (GX-15318), corresponding to
1230/1003 cal yr BP. This is a maximum limiting age
for this moraine which testifies a glacier advance
during the Middle Age or the Little Ice Age. A push moraine
made up of peat was identified at about 1800
m near Malga Materot, in V di Genova. The ·top of
this peat was dated to 200 ± 70 14Cyr BP (GX-15314)
corresponding to 305/0 cal yr BP. This date indicates
a glacier advance of the Little Ice Age. Glacier variations
that occurred in the XIX century AD (Little Ice
Age) have been identified on the basis of historical
maps and photographs
Neotectonic research in applied geomorphological studies.
No full textThe authors illustrate several methods of geomorphological and morpho-neotectonic analysis focused on different practical applications. The first case concerns the research that should be carried out immediately following a destructive seismic event. A second case is related to the planning of major civil engineering works such as power plants and dams, or to geothermal research. -from Author
Proposta di nuova scheda per il censimento dei rock glaciers da fotografie aeree: applicazioni sull’Alta Val d’Ultimo (Gruppo Ortles-Cevedale)
No full textThis research proposes a new database for the census and characterization
of rock glaciers based on the analysis of aerial photographs. The
methodology proposed combin es the stereoscopic observation of aerial
photographs with the use of a GIS for the mapping and identification of
the main morphometric parameters of the deposit s. Use of the GIS, in
fact, allows the measurement of specific parameters (length , width, gradient,
etc. ), The GIS is also used for the management, organization and visualization
of the data , by means of the creation of a database linked with
the geographic elements on the map. On the basis of recent research carried
out in many alpine areas, the information in the database integrate
and update that already available in the literature and used for the Rock
Glacier In ventory of the Italian Alps. In particular, the most recent definitions
have been used regarding the state of activity of the rock glaciers
(classified as active/inactive or relict according to specific characteristics),
their geometry (lobe-shaped, tongu e-shaped or equi-dimensional deposits
) and gener al aspect (simple or composite deposits). Other fields
of the dat abase define the origin of the debris feeding the deposits, their
location, their relation with glacial and nival forms , their relations with
local vegetation boundaries and characteristics of their surface morphology.
The new database was tested in the Uppe r Val d'Ultimo (OrtlesCevedale
Group) , an alpine area of about 30 km2 with a significant variety
of landforms. The application of the database and methodology pro pos
ed enabled us to describe adequately an alpine area distinguished by a
relevant diversity of landforms, giving us a precise and complete starting
point for their monitoring
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