ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

The Fuegian Andes range extend a in W,.E direction, as a
consequence of the subduction of the Pacific Plate underneath
the South American Plate. The maximum altitudes
vary from the 2500 ill a.s.l. in the Cordillera Darwin (Chile,
long. 70° 0) to 700 m a.s.l. in Staten Island (Argentina,
long. 64°). In the studied valleys, the summits do not surpass
the 1200 m a.s.l. elevation.
Bedrock lithology corresponds, from west to east, to a gra".
nitic nucleus, Jurassic acid volcanic rocks and Paleozoic and
Cretaceous methamorphic rocks. The present landscape
shows a glacial modelling which took place during the Last
Glacial Maximum (18-20 ka B.P., Late Pleistocene), when a
mountain glacierization covered the pre-existing relief.
A net of outlet glaciers coming from an ice-mountain cap
filled the entire valley systems, with an equilibrium line altitude
of ca. 300 m a.s.l. The glacier network was also formed
by smaller, high-altitude valley glaciers coming from
lateral cirques which joined the local valley-glacier collector.
This glacier joined then the regional glacier collector,
the Beagle Glacier (200 km long, 10 km wide, 2 km thick).
Erosional glacial features are dominant such as aretes,
horns, cols, truncated spurs, cirques, hanging-valleys, troughs
and rock-basins. The glacial depositional system is
composed of marginal and frontal moraines developed
between 300-150 m a.s.l. and glaciolacustrine plains, many
of them occupied by peat-bogs.
The confluence areas between the minor high valley glaciers
and the valley-glacier collector show erosive features
as hanging valleys and truncated rocky-walls; on the other
hand, between the valley glacier collector and the regional
one, glaciolacustrine terraces, ground moraines, frontal
moraines and kame-terraces are developed.
The stratigraphic correlation of the higher valleys driftunits
with those defined for the regional glacier collector
indicates that the ice-recession would have started during
the beginnings of the Late Glacial (16-14 ka B.P.).
Between 12-10 ka B.P., the equilibrium line altitude would
have ascended to 600 ill a.s.L allowing the depositation of
the morainic systems. The general ice retreat of these valley
glaciers would have taken place between 10-9 ka B.P, giving
rise to glaciolacustrine environments. Presently, the
ice presence is restricted to small cirque glaciers and snow
patches in the cirques (750-1350 m a.s.l.) with an equilibrium
line altitude of ca. 1000 m a.s.l.
ALESSANDRO CORSINI '. MONICA GANDOLFI ',
MAURO MARCHETTI 1, MARIO P ANIZZA 1,
ALESSANDRO PASUT0 2 & MAURO SOLDATI 1
Geomorphological investigations and management of the
Corvara landslide (Dolomites, Italy)
1 Dipartimento di Scienze della Terra, Universita di Modena,
largo S. Eufemia 19,41100 Modena, Italy
2 Irpi Cnr, corso Stati Uniti 4,35127 Padova, Italy
Geomorphological investigations aiming at the recognition'
characterisation and management of mass movements
have been recently carried out in the area of Corvara in Badia
(Dolomites) within the framework of the Newtech
Project, funded by the Environment & Climate Programme
of the European Union.
The area studied, where tourism activities and infrastructures
are highly developed, has been affected by several landslides
since the retreat of the glaciers of the last glacial
maximum and is at present still endangered by active movements
which affect roads, houses and ski pistes,
In 'particular, the investigations have been focused on the
Corvara landslide, the largest (3 krn') and most hazardous
mass movement in the area considered. It is a deep-seated
complex landslide (slump-earth flow) located south-east of
the Corvara village which involves the Pralongia relief
(2088 m a.s.l.); the movement affects the pelitic rocks of
the S. Cassiano Formation (Lower Carnian) and La Valle
Formation (Upper Ladinic) which are particularly prone to
landsliding owing to their ductile behaviour.
Detailed geomorphological survey and analyses of aerial
photographs of different periods enabled the distinction of
several units within the landslide body, this was mainly
carried out on the basis of the degree of activity and frequency.
The most active sector of the landslide is the source
area where retrogressive slides and flows show either
continuous or seasonal mobilisation. On the contrary, the
accumulation area, which stretches as far as the southern
edge of the Corvara village, shows minor longitudinal displacements
but considerable lateral reactivations due to
the erosion caused by two streams which flank the landslide
on each side. The latter are responsible for heavy and
repeated damage to the national road n. 244. It is likely
that this lateral erosion prevents more intense longitudinal
displacements since a condition of equilibrium is determined
between the material deriving from the source area
and that carried away by the water courses.
The drillings carried out up to now have reached the depth
of 40 m without finding any continuous shear surface in
the accumulation area. Therefore, on the basis of the data
so far gathered and in order to detect the main failure surface,
new drillings have been planned together with the installation
of a monitoring system. This will enable a better
understanding of the geometry and kinematics of the landslide
and will lead to a correct assessment and management
of the landslide-induced risk suffered by the village
of Corvara in Badia.
GIAN CAMILLO CORTEMIGLIA
Methodologie pour une evaluation expeditive
des caracteres morphodynamiques des plages italiennes
Dipartimento di Scienze della Terra, Universita di Genova,
corso Europa 26, 16132 Genova, Italy
La determination de l'etat morphodynamique d'une plage
requerit la connaissance non seulement des caracteres
morphologiques et texturales, mais surtout des caracteristiques
ondametriques au brisant, La realisation et l'etablisse-
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