ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

is constituted of four fields within which sediment volume
change data for any pair of beach zones are representable.
These fields are: I (accretion), 2 and 4 (combined erosion
and accretion), and 3 (erosional). The advantages of the
STD are that it enables a quick visualization and assessment
of the relative magnitudes of sediment volume change of
any beach zone pair as well as evaluation of the modal sediment
transport pathways between two adjacent beach zones.
By implication, given the spatial distribution of data
points, subtleties in beach dynamics for different locations
are readily assessed. Copious examples of the applications
and interpretations of STD from morphodynamically- and
texturally-distinct Nigerian beaches are presented.
SERGEI 1. ANTONOV
Small valley development in the center
of Russian Plain during Pleistocene
Faculty of Geography, Moscow State University,
Vorob'yovy gory, Moscou 119899, Russia
The study fluvial relief of the small river valleys of Volga
basin (Protva, Moscow-river and its tributaries), which
contain as buried forms (ancient erosion cuttings) and surface
forms (terranes and morden flood-plain), gives some
regularities of development fluvial erosion and accumulativ
processes. The erosion and alluviation were under the influence
the climatic changers most of all. In accordance
with the datas of the previous researchers (Aseyev, Goretsky,
a.o.), the erosion took place in the end of glaciation
epoch and during the first part of interglacials. The alluviation
occured in the end of interglacials and the first part of
glacials. The new datas show that the processes in the
small river valleys have a same regularities as the processes
in the large valleys of Russian Plain (Bolysov),
The special situation arised during the late part of glacials
in the marginal glaciation zone, where river valleys were
under the influence diferent glacioisostatic movement of
the territory in connection with glacial margin fluctuations.
During this short time as intensive cuttings and mighty alluviation
developed in the cold climatic conditions. In these
intervals the rates of erosion and alluviation were 2-3 times
greater then for the interglacials. (The rate of erosion
was 10-12 mm/year, the rate of alluviation - 1-3 mm/year).
For the Pleistocene the tectonic factor did not play the determinant
role, it served as a special background, which intensified
or reduced the climatic actions and glacioisostatic
factors.
The fluctuations of the main base level of erosion of Volga
basin-Caspian sea did not influence on the erosion and aggradation
processes in the river valleys of peripheral parts
of the basin.
For the Neogene-Middle Pleistocene time the main tendency
of development river valleys was it's gradual alluvia-
tion, which sometimes was interrupted by erosion epochs.
From the end of the Middle Pleistocene (Moscow Ice Age)
for the last 130 k.y. territory did not undergo the actions of
glaciations and the main tendency was gradual deepening
river valleys interrupted by some intervals of intensification
of alluviation processes. In the Odintsovo Interglasial
of the Middle Pleistocene, after intensive accumulation during
Dniper Ice Age, the plan configuration of river valleys
was changed in some parts of basin. And the morden valley
network was formed after degradation of the Moscow
glaciation within the boundaries of river valleys of Odintsovo
age. The mutual position of the ancient and more
young cuttings, buried and morden terraces determined
safety of ancient forms. For example, the Middle Pleistocene
reorientation of river valleys determined the better safety
of the Likhvin interglacial alluvium, but near location
of the cuttings of the Odintsovo and Mikulino age became
a cause of elimination Odintsovo alluvium by the erosion
of the Mikulian interglacial epoch. So this sediment is very
rare in the morden valleys.
Nearly all tributaries of the small river valleys in the Central
Russia have a same age as a small valleys itself. The bad
safety of it's ancient alluvium is a result of the nearly constant
coinsidence the old and young cuttings within the
narrow valley's bottom.
DOMENICO ARINGOLI, BERNARDINO GENTILI,
MARCO MATERAZZI & GILBERTO PAMBIANCHI
Central Apennines Quaternary tectonics and gravity:
chronology of main events
Dipartimento di Scienze della Terra, Universita di Camerino,
via Gentile III da Varano, 62032 Camerino, Italy
The study area is located in the Umbro-Marchean/Latium­
Abruzzi portion of the Apennines and on the periadriatic
side, where limestones, marly limestones, sandstones and
pelitic-sandy-conglomeratic turbidites crop out. A thrust
and fold eastward vergent complex system, connected to
the Neogenic compressive tectonics, built up the ridge.
This process was continued during the Quaternary along
the present coastline; furthermore, geologic evidence and
earthquake focal mechanism interpretations testify its present
activity.
The compressive tectonics and the consequent isostatic response
caused the earliest and huge uplifting of the Apenninic
area, probably during Middle-Upper Pliocene, in a
feeble tectonics stage and likely in arid climatic conditions;
a low energy relief landscape was formed. Therefore, this
ancient landscape was modified and, at the end of Lower
Pleistocene, underwent fast uplifting with an intense extensional
tectonics phase. In the more uplifted areas, the
ancient surface was dislocated with great offset and its vast
portions underwent tilting, rotation and subsidence. The
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