581
00m /in the
southern part
sents the follo-
the lower part of
z 1980/ - Fig.2B.
up of oaloareous
Upper Cretaceous
hese brittle se-
and soft Caino-
of which varies
00m /east- and
Malbork region/,
series occurs
ping gradually
morainio plate-
e to an intensi-
he faults -Pig,3,
d in the numerous
nly on analysis
observed in
ula Delta Plain/
r Cretaceous se-
strongly eroded
whioh acted at
as in Pleistooe-
- even the young-
nd the deltaio
ver. Pleistocene
inner struotuze
b of the diffe-
paoe, as:
ial t marginal,
on, glaciteoto—
iokness of the
ulawy area
tly northwards*
oene series is in
leistooene sedi-
th Holocene depo-
Baslng north- and
b deltaio plain
to lm a.s.l*
»riesj 1 -bounda-
>f top surfaoe of
>reholes and
Figure b. Substratum relief of Quaternary: 1-boundary
of morainic plateau, 2 -oontours of substratum surfa
ce /in m b.s.l./, 3 -lithologic units: a -Cretaceous,
b -Tertiary; 4 -boreholes.
The present Vistula plain seems to be a result of
the Holocene processes, mainly of deltaio accumulation
/Mojski 1983/ and oonsists of moods, silts, sands,
peats and river sands and gravels etc.
Its developments might have ocoured - at least - in
two stages. The first one corresponds to the end of
Tertiary, Due to the intensive Pliooene erosion affec
ting the Tertiary sediments or even Upper Cretaceous
ones a wide depression was formed in this area whioh
has survived till Pleistocene being significant for
the development /accumulation and partially destruc
tion/ of the glacial sediments following each other.
The depression has survived even longer - till Holoce
ne - despite the intensive Pleistooene infilling. In
that last period glaoial sediments have been partially
eroded and removed especially in the time of the last
glaciation by the Vistula river waters. The possible
glaoiisostatio movements and the oscillations of the
level of world ocean basin oaused the following suc
cession of events in the region discussed; - lowering
of the erosion basis /Yoldia period/, - the further
uplift of the southern Baltio seashore zone /Ancylus
period/, - marine transgression /in Litorina period
- due to Scandinavian shield uplift/.
The last process caused - i.e. - the intensive flu
vial accumulation characterised by ohanging directions
of sedimentary transport as well as significant thiok-
ness of the deltaio sediments. The deltaio sediments
were accumulated following the sea regression in a la
goon formed gradually due to the growth of a sand bar
from the west. These different series of Quaternary
sediments have been recognized in uneven degree.
It results from above that for the further discus
sion on character of the lineaments in the area exami
ned such the elements seem to the most significant:
Cretaceous sediments, their top surfaoe relief and the
nature of posturetaoeous tectonic deformation sub—
-Quaternary surfaoe relief, shape and preservation of
the Quaternary sediments.
<i ANALYSIS OF GEOLOGICAL MATERIA IS
The following maps;-of lithology, teotonics and relief
of top surfaoe of crystalline basement, —of tectonics
of lower part of Zeohstein-Mesozoio series /Fig.3,4/
as well as standard geological maps 1:200 000 show the
occurence or suggest as a possibility of some faults
in the area in question at different deep levels. The
possible faults and fractures oocuring in the brittle
oretaoeous rooks reactivated later due to younger and
neoteotonio movements oould have influenced the Caino-
zoic plan of sedimentation as well as the distribution
and circulation of waters in the whole Cretaceous-
-Cainozoio series of the region. The numerous authors
assume the activity of many of suoh the faults in the
period from post-Cretaceous till Quaternary inclusive
and their influence on ¿ulawy development.
It might be, therefore, aooepted that there exists
a pattern of fractures and faults of a different rank
still not reoognized as a whole. It oonoerns the
uppermost part of Zeohstein-Mesozoio series. This sug
gestion seems to be confirmed also by the relief of
Cretaceous top surfaoe and the relief of sub-Quatema-
ry surfaoe and results from the comparison of the ci
ted maps 1:200 000 as well.
As it has been already stressed, also in Polish li
terature /Baiynski 1982/ - in relation to the geologi
cally different regions, the lineaments visible in the
satellite images might represent a surface expression
/projection/ of the inner faults and other teotonlc
elements. The fact has been observed in the regions
with a thin Cainozoic oover as well as in those where
suoh an overburden is muoh thioker them the thiokness
of Tertiary and Quaternary series in ¿utawy Wi^lane
area.
As it results from the boreholes interpretation the
Cretaoeous top surface lies in the ¿ulawy region
slightly higher than in surrounding morainic plateaux
/Pig.5/.
Figure 5. Geologioal cross-seotions. Lithostratigra
phic units: Holocene: 1 -organogenous deposits, varved
days, lake deposits, sediments of fluvial origin, ma
rine and delta plain deposits; Pleistooene: 2 -limno-
glaoial deposits, 3 -glacifluvial and river deposits,
k -glaoial deposits, tills; 5 - sub-Quatemary rocks;
a -Tertiary, b -Cretaoeous; 6 - traces of lineaments
on oross-sections; a -whole set of lineaments, b -li
neaments of the most frequent directions, o -linea
ments which create the regional the regional trends.
The relief of this surface displays some regular
trends whioh may correspond to the ordered pattern
of teotonio linears ocouring within Cretaceous depo
sits or even seem to be characteristic for the whole
Permian-Mesozoio series. The general relief pattern
might be interpreted as the result of erosion facili
tated by such faults. It might be suggested basing on
a lithological character of sediments /brittle oaloa
reous rocks/ and on a position of the studied area
within the platform that the deformations discussed
should occur mainly as not intensive entirely regular
discontinuities of fracture type. These fractures
oould have been active in some periods resulting in
development of the fault and blook structures.
