ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

LILIANA ZAHARIA
Les transports solides et la dynamique du lit fluvial
de la Putna (Roumanie)
Faculte de Geographie, Universite de Bucarest,
1, Bd. Nicolae Balcescu, 70111 Bucuresti, Romania
La Putna est 1'une des plus representatives rivieres de la
«region de courbure» (1'Arc des Carpates et des Subcarpates
roumaines). Grace al'interaction des facteurs naturels
et anthropiques, cette region connait une dynamique tres
accentuee du relief, indiquee, parmi d' autres parametres,
par Ie taux d' erosion Ie plus intense de la Roumanie. Par
consequent, la charge d' alluvions en suspension de la Putna
et de ses affluents atteint des valeurs qui, dans Ie secteur
des Subcarpates, depassent 10-15 t/ha/an (pour l'ensemble
du pays ce parametre est de 2 t/ha/an environ).
Notre etude presente 1'analyse des series de temps des debits
d'alluvions en suspension et met en evidence la tendance
de la dynamique verticale du lit fluvial de la Putna et
de ses affluents principals. Generalement on constate une
tendance a la degradation aux sections situees dans la region
montagnarde et une tendance al' agradation aux section
de la region collinaire.
VLADIMIR S. ZALETAEV
Biogenic relief in arid and semiarid zones of
Central Asia, genesis and ecologicalrole
Laboratory ofDynamics of Terrestrial Ecosystems,
Water problems Institute, Russian Academy of Sciences,
10, Novaya Basmannaya st., Moscou, 107078, Russia
Biogenic relief on arid and semiarid territories in reality
occupies more significant places than it is supposed. Special
geomorphological researches done in various landscapes
ofsandy, loess, clay deserts and semideserts of Central
Asia, Kazakhstan and the south of Russia showed that vegetation
cover, active ground-digging, «building» activity
of animals, their trophicallinks with plants and impact on
the soils on the pastures appear to be the powerful factor
of straight influence on relief of ground as well as transforming
relief-forming effect of aeolian processes and processes,
connected with surficial flow of precipitation, with water
erosion and with accumulation and spare of ground
water.
Several zonal-typical form of relief in subboreal northern
and subtropical southern deserts (including deserts of Kara-Kum,
Kizil-Kum, Usturt, deserts of Mongolia and semideserts
of Northern Precaspian plain and south of Tuva)
formed as .the result of biogenic and abiogenic environmental
factors interaction. It refers as to forming of speci-
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fic types of nano, micro and mesorelief on the sandy, clay
and even stone substrates and also such macroforms as hillock,
row semianchored sands and «zoogenic depressions
relief» of clay desert, that in its turn arose the mosaic
damp soil and complexity of vegetation cover.
Animals activity often serves as initiation factor defining
the changes in direction of morphogenesis on the ground
on the vast territories. As the result of synergetic effect,
that appears under wind impact and digging of animals
(mostly Rhombomis opimus, Meriones meridianus, M.lybicus,
M.tamariscinus) Spermofilopsis leptodactilus, Citellus
fuluus) the specific class of «zoo-aeolian» and «zoo-phyteaeolian»
processes begin. The result of them is the Hillock
sandy relief of «ephedro-peschanko towns» - complicated
hillock-like bars up to 10-20 m at the bottom and up to 5
m high. These bars have table form, sometimes complicated
by phytogenic «ephedra hills». This type of relief is
characteristic for the deserts of Eastern Kara-Kum. The
author showed for the first time the formation mechanism
of this relief type of sandy deserts and also other characteristic
forms of relief of Asian sandy deserts and clay semideserts.
Large quantity of various forms of micro, nano and mesorelief
of clay semideserts is conditioned not only by straight
impact of animals on the ground, but also by arousing
of «zoopedohydromorphous geomorphological processes»
and «zoophytohydromorphous» in their concrete regional
geographical determined manifestations.
MILOS ZEREMSKI
Les morphostructures des blocs en tant que
principaux elements des processus neotectoniques
de la Serbie Centrale
Institut geographique «]ovan Cvijic» de l'Academic Serbe des Sciences
. et des Arts, Knez-Mihailova 35, Belgrade, Yougoslavie
Le relief de la Serbie centrale (la Sumadija) dont on considerait
jusqu'au milieu de ce siecle qu'il avait resulte des
processus abrasifs de la mer pontique (Cvijic, 1909) et plus
tard qu'il est d'origine fluvio-denudante (Jovanovic, 1951
& alii), comprend des blocs de morphostructure en tant
que principaux elements des processus post-pontiques
neotectonique, Ces blocs ont ete examines par rapportala
direction de leur propagation-rectilignes, en arc (conditionnes
par les failles et les blocs de magma); ensuite, par
rapport alahauteur relative-positifs, negatifs; par rapport
a la position des vallees - non-concordants, epigenetiques,
pseudo-epigenetiques, concordants, divergents, convergents;
par rapport al' aspect morphologique - en forme de
vo te-inverse, en fome de vo te-conforme, (en forme de
plaques de biais, de fosse, de cuvette, de ravin, de depression)
et, enfin , par rapport al'age, ils ont ere crees de presarmatien
jusqu'au pleistocene recent.