extended abstracts - Geomorphic Processes and Geoarchaeology

Geomorphic processes and geoarchaeology
loam and in some places by limnoglacial sands. From the NE to the SW the plain is
crossed by hills and ridges of Vaulinogosky marginal complex. The other remarkable
geomorfological features are drumlin hills, which form the Pskovsky drumlin field [1].
Geological and geomorphological сharacteristics determine the orolitogenic basis
of modern Kamno vicinity. They allow us to reconstruct the paleolandscape features of
this territory for the Holocene epoch.
The landscape features of the settlement Kamno began to form during the
preboreal and boreal periods of Holocene epoch after the dissapearance of the Chudskoye
ice-dam lake [2], when there happened the climate warming.
During the boreal climatic period the average temperature of July and annual
temperatures at the latitude of Kamno settlement were only 5-2 C lower than today and
annual atmospheric precipitation was only 50 mm more. At this relatively warmer time
the preglacial valley of the Kamenka river and its gullies got free from the dead ice
fillings. As the result the ancient cuttings got partially filled with sediments which melt
out from the dead ice. Thus, towards the end of boreal period of Holocene the preboreal
fitolandscapes of tundra-forest-steppe zone were replaced by forest fitolandscapes of
taiga zone. In these forests mainly pine and birch with some fir-tree and alder-tree
(to10 %), and oak, elm and linden (2-4 %) grew.
However, at that time the local peculiarities of relief, mother rock soil and the
extent of wetting began to influence the plants group composition. These peculiarities
formed the landscapes of waterless meadows with a sparse growth of trees at the well
drained watershed spaces of the Kamenka river valley and its gullies and also the
landscapes of forests at their slopes and bottoms which had more wetting [3].
During the early Holocene the Velikaya river had a Pskovsko-Chudskoy segment
of its valley. It occupied a large part of the then drained depression of the modern
Pskovsko-Chudskoye Lake and the Velikaya river flew into the Small Chudskoye Lake.
This lake was a relict of the Chudskoye ice-dam lake. It occupied the deepest northern
part of the Pskovsko-Chudskaya depression and its water level almost reached the 20 m
absolute mark. This water level was the basis of the Velikaya river erosion. Due to this
fact the water- level of the Velikaya river at the place, where the Kamenka river flows
into it, was10 m lower than today (30,5 m) and the Kamenka had larger waterfall angles
and speed of flowing than now.
However, dissapearance of glacial pressure on the earth crust at the area of the last
glaciation provoked the compensatory isostatic raising of this territory It was quicker at
the northern part of the Pskovsko-Chudskaya depression than at the southern part. For
this reason a warp of depression in the southern direction took place and thus, as the
stream of water flowing from the Small Chudskoye lake into the Baltic sea became
difficult, the waters began to fill the lacustrine waters of the Pskovsko-Chudskaya
depression and thus the transgression of these waters in southern direction started. As a
result of this transgression the Pskovsko-Chudskoy segment of the Velikaya river valley
stopped its existence. A lake with the water level of 25 m absolute mark was formed and
the lower tributaries of the Velikaya river turned into estuary type bays [4]. At the same
time a similar lake bay in the Kamenka river valley began to form.
In the middle of subboreal period of the Holocene the climatic conditions grew
worse: summer, winter and average annual temperatures became lower and annual
precipitation quantity increased. This climatic change brought about an increasing share
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