ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

and impact sediment transport systems in the evolving basins.
In the vicinity of Loreto, we find surprisingly, that the
accomodation zone may either remain active or become
reactivated, and effect both topography and the sediment
source areas for rapidly subsiding Pliocene basins.
RAM K. MAZARI & T.N. BAGATI
Geomorphology of soft rock sediments
of the Northwestern Trans Himalaya
Wadia Institute of Himalayan Geology, Dehra Dun, 248 001, India
The northwestern Trans Himalaya includes the regions of
Ladakh, Lahul and Spiti and lies in the cold and dry climatic
belt of the Himalayan mountain ranges. Great .many
valleys in this belt are infested with a variety of Quaternary
deposits which have been shaped to attractive configurations
by a variety of processes over a period: oftime..In-essence
the morphological features that have developed on
these sediments are reminiscent of environmental changes
that have occurred primarily on account of uplift related
climatic alteration.
The morphological features developed on the soft rock sediments
of the valley bottoms may be classified into two types
i.e. riverine and lacustrine. A third and contrasting type'
may -be added from the slope deposits. Riverinesediments
are mainly the product of. glaciofluvial-outwash,
whereas discrete lacustrine deposits represent the impounded
stretches of the valleys developed by tectonically dislodged
slope material and/or climate sensitive process
change. The morphological features produced on indurated
riverine-sediments include mono-block cathedrals, nested
cathedrals, story in story cathedrals, earth pillars,
combs, murals, caves and, amphitheaters. In dry lacustrine
sediments the predominant morphological features are railing
posts, flutes and grooves, funnels, tunnels and arches.
Among the slope deposits channel chutes and levees represent
a significant set of features.
Sediment composition, facies variation and matrix have
played an, important role in the development of various
features in the soft sediments. Riverine sedimentsprincipally
belonging to limestone catchment show marked degree
of induration compared to non-calc catchments. Induration
itself has provided a strong grain in the development
of tall and extensive morphological features in these
sediments. In the case of lacustrine deposits variation in
the morphological features is time dependent being determined
by the occurrence of the event and subsequent sediment
accumulation. Major lacustrine deposits date back to
more than 45,000 yr B.P. (Bagati & alii, 1996) Thus, old
and thick lacustrine sequences exhibit variety in the
morphological build up, whereas young and relatively thin
sequences show subdued geomorphic architecture. Featu-
268
res on slope deposits on the other hand are determined by
the bed rock angle and catchment characteristics and their
response to the climate.
From the build up of the morphological features it is evident
that moist regime was once a predominant geomorphic
agency in the Trans Himalayan belt but as uplift
of the Higher Himalaya progressed from Middle Pleistocene
onwards, moisture gradient tilted sharply southward
rendering the region cold and dry and the eventual development
of the micro landforms. Seasonal snow thawing
and aeolian activity is a dominant external energy in the
Trans Himalaya for the development of various micro geomorphic
features. The mode of origin of the various micro
landforms has been discussed.
MALGORZATA MAZUREK
Variations in fluvial transport as a response
of the catchment system in a young glacial area,
West Pomerania, Poland
Quaternary Research Institute, Adam Mickiewicz University,
ul. Fredry 10,61-701 Poznan, Poland
In the contemporary denudation system ofthe temperate
zone, fluvial transport plays a fundamental role in carrying
away .matcrial from erosion and denudation in a catchment.
A detailed analysis of fluvial transport allows it to be
recognised as an indicator of relief evolution, including soil
leaching and erosion.
The object of investigation was the Kluda catchment, which
is a part of the upper Parseta hydrographic system and
which is considered representative of the young-glacial zone
of West Pomerania and the Polish Plain. The study is
based on the data from four hydrological years 1990-1993.
Water sampling was carried out once a month in 31 sites
that were located on small tributary streams in order to reflect
the range of geological, land use and topographical
conditions.
The solute load predominates over the suspended and bed
loads in the structure of materials transported in the Kluda
gauging profile. This structure remains unchanged even
during large floods. The ratio of dissolved to suspended
load is influenced by weathering processes, the amount
and nature of solutes available in the drainage basin, and
the character of water cycle (water residence times).
Substances dissolved in river water may come from the atmosphere,
the biological cycle, and primarily from the processes
of chemical weathering taking place in the soil and
deeper down in the substratum. The transformation of precipitation
into runoff is associated with the constant change
in the physical-chemical parameters of water involved in
the water cycle. Variations in the concentration of Ca+2, K+,
S04-2, HC0 3
and Si02 ions can be useful as natural indica-