218
A. Krawiec
easterly direction towards the altitude of ca. −100 m amsl In deep erosion depressions, the Mesozoic roof sometimes reaches the altitude of −250 m amsl—e.g., the
Dre˙ zewo channel, or even −340 m amsl—the region of D˛ abki [13]. The Neogene
and Paleogene deposits are present in the central and eastern parts of the Polish
Baltic coast. Those are mainly Oligocene clay and sands, as well as sands, siltstone,
and claystone with the interbedding of Miocene brown coal (Fig. 10.3) [14]. The
Palaeocene, Eocene and Pliocene sediments are fragmentarily preserved in the form
of isolated patches of mostly sand and gravel, with interlayers of clay and silt. In
the western part of the coast, Neogene and Paleogene deposits do not occur, and
Pleistocene glaciofluvial sediments are deposited directly on Mesozoic rocks.
The Quaternary sediments occur on the terrain surface all over the Baltic coast.
They usually form alternate sequences of boulder clay and sand strata, sometimes also
with muds and clays. The substratum and the thickness of the Quaternary deposits are
varied; the latter ranges from 30 m in the region of Kołobrzeg, Darłowo, and Gdynia
to over 200 m in the area with deep fossil valleys near the town of ˙
Zarnowiec.
In the estuarial parts of the river valleys and ice-marginal valleys, in the areas of
coastal lowlands and the ˙
Zuławy region, the Holocene sandy and organic sediments
can be found—peat and alluvial muds, while sand barriers and peninsulas formed in
the other parts of the Baltic Coast. The southern Baltic Coast is mostly of a sedimentational type, being levelled with sand barriers since the Littorina transgression, i.e.,
during the last 7000 years. The cliff type coast, in which the Pleistocene and locally
the Neogene sediments are exposed, accounts for about 15% of the coastal line.
10.3 Hydrogeological Conditions After the Review
The Baltic Sea forms a discharge area for all the multi-aquifer formations and groundwater flow systems recharged from the moraine uplands within the coastal belt of
Lakelands, where the elevation exceeds 200 m amsl, and locally even 300 m amsl.
Fresh groundwater can be found mainly in the Quaternary, Neogene, Paleogene,
Cretaceous, and locally in the Jurassic strata in the western part of the Polish coast.
The conditions of the first surface aquifer vary according to the extent of the main
geomorphological-geological units, which consist of:
– dune barriers that separate lakes or coastal lagoons from the Baltic Sea, including
the Hel Peninsula,
– coastal lowlands, including river valleys and the Vistula delta,
– the highest upland hills and cliff coasts (Fig. 10.4).
On the southern Baltic coast, common groundwaters occur mainly in the Quaternary aquifer. In the western part of the coast, freshwater is extracted locally from the
Cretaceous aquifer in the syncline of Trzebiatów and occasionally from the Jurassic
aquifer e.g. in the towns of Mrze˙ zyno, Podczele and Pogorzelica (Figs. 10.2 and
10.3). On the eastern coast, apart from the generally exploited Quaternary aquifer,
also the Miocene, Oligocene and Cretaceous aquifers are exploited (especially in the
A. Krawiec
easterly direction towards the altitude of ca. −100 m amsl In deep erosion depressions, the Mesozoic roof sometimes reaches the altitude of −250 m amsl—e.g., the
Dre˙ zewo channel, or even −340 m amsl—the region of D˛ abki [13]. The Neogene
and Paleogene deposits are present in the central and eastern parts of the Polish
Baltic coast. Those are mainly Oligocene clay and sands, as well as sands, siltstone,
and claystone with the interbedding of Miocene brown coal (Fig. 10.3) [14]. The
Palaeocene, Eocene and Pliocene sediments are fragmentarily preserved in the form
of isolated patches of mostly sand and gravel, with interlayers of clay and silt. In
the western part of the coast, Neogene and Paleogene deposits do not occur, and
Pleistocene glaciofluvial sediments are deposited directly on Mesozoic rocks.
The Quaternary sediments occur on the terrain surface all over the Baltic coast.
They usually form alternate sequences of boulder clay and sand strata, sometimes also
with muds and clays. The substratum and the thickness of the Quaternary deposits are
varied; the latter ranges from 30 m in the region of Kołobrzeg, Darłowo, and Gdynia
to over 200 m in the area with deep fossil valleys near the town of ˙
Zarnowiec.
In the estuarial parts of the river valleys and ice-marginal valleys, in the areas of
coastal lowlands and the ˙
Zuławy region, the Holocene sandy and organic sediments
can be found—peat and alluvial muds, while sand barriers and peninsulas formed in
the other parts of the Baltic Coast. The southern Baltic Coast is mostly of a sedimentational type, being levelled with sand barriers since the Littorina transgression, i.e.,
during the last 7000 years. The cliff type coast, in which the Pleistocene and locally
the Neogene sediments are exposed, accounts for about 15% of the coastal line.
10.3 Hydrogeological Conditions After the Review
The Baltic Sea forms a discharge area for all the multi-aquifer formations and groundwater flow systems recharged from the moraine uplands within the coastal belt of
Lakelands, where the elevation exceeds 200 m amsl, and locally even 300 m amsl.
Fresh groundwater can be found mainly in the Quaternary, Neogene, Paleogene,
Cretaceous, and locally in the Jurassic strata in the western part of the Polish coast.
The conditions of the first surface aquifer vary according to the extent of the main
geomorphological-geological units, which consist of:
– dune barriers that separate lakes or coastal lagoons from the Baltic Sea, including
the Hel Peninsula,
– coastal lowlands, including river valleys and the Vistula delta,
– the highest upland hills and cliff coasts (Fig. 10.4).
On the southern Baltic coast, common groundwaters occur mainly in the Quaternary aquifer. In the western part of the coast, freshwater is extracted locally from the
Cretaceous aquifer in the syncline of Trzebiatów and occasionally from the Jurassic
aquifer e.g. in the towns of Mrze˙ zyno, Podczele and Pogorzelica (Figs. 10.2 and
10.3). On the eastern coast, apart from the generally exploited Quaternary aquifer,
also the Miocene, Oligocene and Cretaceous aquifers are exploited (especially in the