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including the location, number, and age of Holocene wave-cut cliffs (submerged
coastlines).
The south-eastern (SE) Baltic is an excellent area to study fossil coastline forma-
tion, since it was not affected by tectonic isostasy-associated movements during the
Holocene. The zero isobase at various evolutionary stages in the Baltic history has
been assumed to be located in the southern Baltic (e.g. Eronen 1988 , Ignatius et al.
1981 , Uscinowicz 2003 ) .
As opposed to the adjacent slopes, the SE slope of the Gdansk Basin shows
well-preserved traces of the fossil coast. However, we concur with Uscinowicz
( 2003 ) in contending that there is an absence of sufficient bathymetric informa-
tion collected specifically for the purpose of adequate identification of fossil coasts.
The erosion-accumulative platforms were assumed to have evolved below the cliff
base when the sea level stabilized. Such interpretations were usually inferred from
bathymetric charts developed by interpolating depth data from navigational charts.
However, erosion surfaces of wave-cut platforms may be covered only by a thin
layer of lag deposits or by later sediments, occasionally a few metres thick. In such
cases, bathymetry-based spatial correlations of wave-cut platforms are inaccurate.
Furthermore, some distinct changes in the bottom profile curve, previously inter-
preted as typical relics of cliff shores or simply as submerged wave-cut cliffs, are
structure-dependent erosion formations. To render the matter still more complex,
difficulties are encountered when dating wave-cut platforms, identifying corre-
sponding forms in the modern cliff morphology, and determining their relationship
with the mean sea level at the time of their formation.
Moreover, the existing knowledge concerning fossil coasts on the submerged
slopes of the SE Baltic is strewn with conflicting information, as all reconstruc-
tions were based on fragmentary data collected in the mid-twentieth century during
cruises involving very rough geographical positioning and primitive echo-sounders.
At that time, before the computer era, the analogue echograms obtained were
processed manually, which contributed significantly to the subjectivity of data
interpretation.
Thus, the first step in future studies aimed at palaeogeographic reconstructions
in the Russian sector of the SE Baltic should involve a survey and update of the
existing data on the fossil coast levels, based mainly on depth measurements.
This study was aimed at gaining an insight into the ancient coast levels in the
SE Baltic, based on modern verifiable bathymetric information and the use of
geoinformation techniques.
The chronology used in this paper is based on the conventional carbon year ( 14 C)
BP approach.
10.2 Study Area
The structural geology of the south-eastern Baltic Sea is characterized by a syncline
slope of a complex block character. The top of the sedimentary bedrock consists
of Upper Cretaceous marls, sandstones, and cemented siltstone. The highest block,
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