Middle Miocene palynoflora of the Legnica lignite deposit complex ...

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and Osmunda are numerous (Sadowska et al.
1976, 1981).
The plant communities, both swamp and
mesophilous forests outside the marsh basins,
became once more fl oristically rich, and dominated
by plants of relatively high climatic
requirements, representing warm-temperate
element, whereas palaeotropical element was
distinctly poorer and with smaller taxonomic
differentiation (Tab. 1). In comparison with
the Lusatian seam the proportion of Tricolporopollenites
pseudocingulum, Engelhardia,
Quercoidites henrici, Araliaceae (excluding
Legnica 7/58 profi le), and Ilex pollen is low.
In addition, here there are more pollen grains
of Nyssa, Alnus, Quercus, and Fagus. Pollen
grains of Tricolporopollenites liblarensis
(+ T. fallax) occur sporadically (Sadowska et al.
1976, 1981). The climate was warm-temperate
and humid. There was again the time of slowly
fl owing waters and large-area marshes with
low peat-bogs on the accumulation terraces
(Piwocki & Ziembińska-Tworzydło 1995, 1997).
In the Legnica region swamp forests and bush
swamps grew. In drier terrains there existed
favourable conditions for mixed mesophitic
forests with the domination of warm-temperate
taxa, and with an admixture of evergreen
plants, mainly forming the undergrowth. In
samples from the grey clays arctotertiary taxa
prevail, but relatively high diversity of palaeotropical
element (Tab. 1) points out a still
warm, mild and humid climate, favourable for
swamp and riparian plant communities.
In pollen diagrams of these sediments from
various regions of Poland (both distant and
near ones, even in the same locality), we can
observe differences in contributions of pollen
grains of individual taxa (genera and families),
which refl ect changes of plant communities.
These differences agree with the kind of sediment
and are connected with changes of edafi c
conditions. This problem has been studied by
Dyjor and Sadowska (1977). On the basis of
profi les of the Henryk seam from many localities
(Nowe Czaple, Tuplice, Staszów, Mirostowice,
Gozdnica, Ruszów, Milików, Wołów,
Łojowice, Jaworzyna, Żarów, Rusko, Jerzmanowa,
Tarpno, Chróścina, and Wielowieś)
the main features differing this seam from
other ones have been given (Dyjor & Sadowska
op. cit.). In addition, profi les from the Zielona
Góra region (Sadowska et al. 1973, 1974), Żary
and Mirosławice (=Mirostowice; Doktorowicz-
Hrebnicka 1954, 1956b), Rogóźno deposit (Doktorowicz-Hrebnicka
1961, Mam czar 1961),
Konin region (Kremp 1949, Mamczar 1960),
margin of the Bełchatów graben (Sadowska
1974), upper coal series from Bełchatów
(Kościelniak & Wanat 1974), and Ustronie
(Ziembińska & Niklewski 1966, Ziembińska-
Tworzydło 1974) were recognized as analogical
ones. The main stratigraphic criterion was
a variable percentage of pollen grains of thermophilous
families and genera (Quercoidites
henrici, Myrica, Tricolporopollenites pseudocingulum,
Engelhardia, Symplocos, Araliaceae,
Araliaceae/Cornaceae, Araliaceoipollenites
edmundi (=Tricolporopollenites edmundi),
Itea, Arceuthobium, Meliaceae, Solanaceae,
palms, and Tricolpopollenites liblarensis) in
individual stages of the Miocene. In samples
from the Henryk seam they make up on the
average 5.8% (in comparison in the 2 nd Lusatian
seam 14.9%, in the Kędzierzyn seam 2.5%).
In comparisons of these profi les the attention
was also paid to percentage contribution of pollen
grains of temperate and warm-temperate
plants, including Abies, Picea, Tsuga, Sciadopitys,
Betula, Carpinus, Corylus, Ostrya, Quercus,
Fagus, Castanea, Ulmus, Celtis, Parrotia,
and Acer. In samples from the Henryk seam
they make up an average of 25.4% (in the 2 nd
Lusatian seam 17.5%, in the Kędzierzyn seam
39.2%). Sporomorphs of the facial element
have the highest frequency (60–80%) in all
these profi les. Their differentiation in individual
profi les is a result of various ecological and
regional conditions (Dyjor & Sadowska 1977).
In many palynological profi les from the
Polish Lowland (for example from the Wyrzysk
region – Kohlman-Adamska 1993) towards the
top of cores an increase of the contribution of
Alnus pollen grains can be observed, what is
interpreted as a result of changes in taxonomical
composition of the swamp forest. During the
sedimentation of the 2 nd Lusatian seam there
probably were forests with the domination of
Taxodium, Nyssa and Glyptostrobus, while
during the sedimentation of the 1 st seam there
were forests with a considerable role of Alnus.
In the Legnica profi les pollen grains of Alnus
reach a few per cent in the Lusatian seam, in
the Mużaków series – up to 70%, in the Henryk
seam – up to 16%, and in the grey clay
horizon – up to 50%. So, we can assume that
during accumulation time of the Mid-Polish
group of seams (Henryk seam) and grey clays