ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

SIRIO CICCACCI 1, VINCENZO DEL GAUDIO 1,
LUIGI LA VOLPE 2
& PAOLO SANS6 1
Geomorphological features of Monte Vulture
Pleistocene volcano
(Basilicata, Southern Italy)
1 Dipartimento di Geologia e Geofisica, Universita di Bari,
via Orabona 4,70125 Bari, Italy
2 Dipartimento Geomineralogico, Universita di Bari,
via Orabona 4, 70125 Bari, Italy
The Monte Vulture volcano is located on the eastern border
of Southern Apennines at the inner margin of the Bradanic
foredeep. It belongs to the Roman Comagmatic Province
though it is atypical because of its particular position
(it is the only volcano of this Province not aligned along
the Tyrrhenian Sea margin on the western side of Apennines)
and some differences in the chemical composition of
its products. Monte Vulture is formed by a central cone of
altitude 1327 m and secondary eruptive centres mostly placed
in the peripheric areas. The volcanic products are
spread over an area 184 km 2 wide and represent the result
of explosive and effusive activity occurring from the Midd­
Ie Pleistocene (about 730 ky B.P.) until the Upper Pleistocene
(about 132 ky B.P.).
A multi-disciplinary method taking into account geological,
petrographic, volcanological and morphological
aspects was used to reconstruct the geomorphological evolution
of Monte Vulture.
The geomorphological analysis was performed using different
complementary methods. The morphographic study
was carried out by means of aerial photo interpretation
and detailed field survey which supplied the basis for a detailed
geomorphological map. It displays not only the volcanic
landforms occurring in the area and their chronological
sequence, but also the tectonic control on the geomorphological
evolution of the volcano.
The morphometric study concerned both the hydrographic
network and the relief physiography of the area.
As regards the drainage net, the geometry, the degree of
organization and the preferential orientation of streams
were examined according to a well-known method, widely
described in literature. The morphometric study of the relief
was carried out by means of spectral analysis of the
physiographic features of the area. This method allowed
landforms of different magnitude to be separated, starting
from a numerical representation of surface in the form of a
regular grid of altitude values. The land surface analysis
was realized by means of the Fourier transform which reduced
the surface analysed to a number of sinusoidal wavy
surfaces with different possible wave lengths. A synthetic
view of all the elementary surfaces forming a landscape
was supplied by a bidimensional amplitude spectrum, generally
characterized by the presence of relative maxima.
The position and the values of these relative maxima allowed
both preferential patterns in the development of
landforms and the length and the orientation of the main
sinusoidal surfaces to be recognized.
Together, the data collected have allowed the volcanological
and geomorphological evolution of Monte Vulture to
be reconstructed. In particular, the study points out that
this evolution was strongly influenced by recent tectonic
activity linked to four main tectonic directions NW-SE,
NE-SW, E-W, N-S oriented. On the other hand, the analysis
suggests that the main landforms of the area cannot be
related to flank instability of the volcanic cone.
The volcanic activity began in a depressed area bordered
by NW-SE and NE-SW scarps which could represent a
graben-type structure. Tectonic alignments with the same
orientation led the geomorphological and volcanological
. evolution and have been active until very recent times as
they have influenced the present drainage network evolution
In more recent times the N-S and E-W tectonic alignments
also seem to have played an extremely important role
in the landscape evolution. In particular, the former borders
the volcanic area along its eastern side and characterizes
the area between Atella and Rionero which is probably
a graben-type structure filled up with pyroclastic and
lahars deposits. The latter alignment induced the lowering
of the southern sector of the main volcanic cone in correspondence
with the Valle dei Grigi-Fosso Corbo alignment.
This lowering occurred about 480 ky B.P. and strongly
influenced both the volcanic evolution and the general
morphology of the central cone. The E-W tectonic direction
has strongly influenced also the drainage network development
up to the present as the numerous anomalies
characterizing the drainage pattern testifies.
ALDO CINQUE 1, PAOLA ROMANO 1
& HELDER DE ANDRADE E SOUSA 2
The Pliocene-Pleistocene coastal terraces
of Luanda Region (Angola)
1 Dipartimento di Scienze della Terra, Universita di Napoli Federico II,
largo S. Marcellino 10, 80138 Napoli, Italy
2 Departamento de Geologia, Universidade A. Neto, Luanda, Angola
A long portion of Angola's Atlantic coast is characterized
by a widely-extended surface of very low relief that spans
between 50 and 170m of altitude. This surface is particularly
wide in the surrounding of Luanda where it extends
up to 50 km inland, mantaining a mean slope towards the
ocean of about 0.2 0/0. The tentative reconstructions reported
in the existing literature about the origin and age of
this surface appear unsatisfactory both for the lack of
objective constraints and for the abuse of correlations
traced between non-equivalent sectors of that composite
surface.
As a matter of fact, the coastal strip comprised between 50
and 170 meters a.s.l. discloses morphological features that
allow to interprete it as a polycyclic landscape resulted
from different phases of planation and downcutting. Such
landscape unconformably cuts across a faulted and warped
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