ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

(maille de 80 m) puis echantillonnage stratifie, 80 profils
tariere avec mesure du pH eau de l'horizon A, 5 fosses pedologiques
avec analyses completes des differents horizons
(granulometrie, pH, M.O., C/N, CEC, P, K, Ca, Mg) ont
ete effecrues en faisant appel aux nouvelles techniques de
localisation et de gestion des donnees (tacheomerre electronique
et balise Gps differentielle pour les leves de terrain,
logiciels Pc Arc-info et Idrisi pour l'analyse spatiale
des donnees et Vistapro pour les visualisations 3D a partir
d'un modele numerique de terrain au pas de 2,5 m elabore
a cette occasion). Les resultats de l'etude pedologique ont
ensuite ete confrontes aux donnees de la vegetation (38 releves
de vegetation, mesure de la biomasse produite et offerte
au paturage, analyse de la valeur nutritive (cellulose
brute, N, P, K, Ca, Mg) sur deux annees (1995,1996) afin
de mieux comprendre Ie comportement des animaux au
paturage, dans un contexte de sous chargement.
Cette nouvelle approche a permis d' etudier la dynamique
des sols a plusieurs echellcs de temps (le quaternaire pour
la repartition des saupoudrages et leur incorporation dans
Ie sol, les decennies passees pour decrire la situation actuelle,
les evolutions recentes a court terme en fonction de
la pression de paturage) et de realiser des visualisations 3D
explicatives des modeles proposes. Elle facilite en outre la
confrontation avec les donnees ecologiques et du comportement
animal dans une approche globale destinee a simuler
les evolutions probables de la vegetation en fonction du
type de paturage.
PIOTR MIGON
Weathering mantles and their bearing
on the long-term landform evolution of the Sudetes, SW
Poland
Department of Geography, University of Wroclaw,
pl. Uniwersytecki 1,50-137 Wroclaw, Poland
Two types of weathering mantles have been for long recognised
in the Sudetes Mountains and their foreland, SW
Poland. These are kaolinic mantles, regarded as indicative
of advanced alteration in hot humid climatic conditions,
and 'immature' grus weathering mantles, developed largely
but not exclusively on granite. Their distribution reflects
the gross morphological division of SW Poland as the former
occur in tectonically downthrown areas subject to net
accummulation since the beginning of the Neogene whilst
the latter are typical for higher grounds of net denudation.
The age of kaolinic mantles is constrained by the age of
overlying sediments and is Palaeogene-early Miocene,
although the onset of kaolinisation is likely to be at least
Cretaceous in age. The gruses are believed to be younger,
Pliocene-Pleistocene in age.
Products of kaolinic alteration cover the landscape that represents
a mantled and partly stripped etchsurface. As su-
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ch, it gives an insight as to how the early Tertiary topography
may have looked like. Highly varied relief with
strong lithostructural control had already formed in the
Palaeogene and, consequently, the widely held concept of
the 'Palaeogene planation surface' finds little support. It
seems that the hilly landscape of the Sudetes may be to a
large extent a stripped etchsurface rather than a product of
erosional dissection subsequent to the late Neogene tectonic
movements. Moreover, the widespread occurrence of
the kaolinic mantles in the Sudetic Foreland shows that the
topography is primarily inherited and little overall change
has taken place in the last ca. lOrna.
Controversy surrounds the grus weathering, its age and palaeoenvironmental
significance. Overlying sediments suggest
that the grus profiles may vary in age, the oldest being
at least Pliocene and the youngest late Pleistocene-Holocene.
Their close adjustment to the present-day topography
indicates that the grus profiles are unlikely to be roots of
former weathering mantles of enormous thicknesses which
have been eroded away. Several features suggest that the
grus weathering profiles vary as to the way they have behaved
during the Quaternary. Some have been truncated
and/or buried which may have caused fossilization, whilst
the other have been progressively deepened or renewed in
response to discrete episodes of uplift and/or climatically
driven changes in the course of surficial geomorphic processes.
In particular, deep grusification is characteristic for
footslope settings where water availability and protection
of permeable slope sediments provide optimal conditions
for deep weathering to proceed. Therefore, they by no
means may be regarded as relict. Thus, it is possible to use
the weathering profiles as indicators of the current dynamics
of the landscape.
BOGDAN MIHAI l
& ILEANA PATRU 2
Man- relief relation among middle mountain spaces:
a comparative case study
1Bulevardul Republicii 283, BI. 3A, Apt 21,
Ploiesti- Prahova 2000, Romania
2 Bulevardul Stirbei Voda, Bl.A4., Er], II, Apt 13,
Craiova-Dolj 1100, Romania
The Romanian Carpathians are mountains with an important
fragmentation degree, having a big population and
settlement density and a great variety of human landscapes.
Human being has actively adapted to the carpathian
environment for centuries (since Neolithic).
This case study is a comparative approach of two areas
with similar morphologic conditions but extremely different
human landscapes: the Bran- Rucar Corridor and the
Upper Prahova Corridor.
The Upper Prahova Corridor is a transversal axis with an
accelerate dynamics after 1850 because of the opening of