Acta Palaeobotanica 49(1): 5–133, 2009 Middle Miocene palynofl ora of the Legnica lignite deposit complex, Lower Silesia, Poland ELŻBIETA WOROBIEC W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland; e-mail: [email protected] Received 18 November 2008; accepted for publication 11 May 2009 ABSTRACT. Palynological analysis of three profi les of the Miocene deposits from Legnica site (east fi eld, 33/56 and 41/52 profi les) and Ruja site (fragment of the Komorniki 97/72 profi le) has been presented. The samples consisted of material from the 2nd Lusatian lignite seam, the Mużaków series, the 1st Henryk lignite seam and grey clays of the Poznań series. The age of the fl ora was defi ned as Badenian (?Late Karpatian – Late Badenian). During the studies a total of 201 taxa from 96 genera (including 195 taxa from 92 genera of pollen and spores) were identifi ed. The systematic part of this work gives descriptions of selected sporomorphs and phytoplankton microfossils. Some informations about botanical affi nity, occurrence in fossil fl oras and in the studied material, as well as about allied recent plants are given in remarks. The results are presented in three pollen diagrams. The taxa have been classifi ed to an appropriate palaeofl oristical element mainly on the basis of the checklist of selected pollen and spores taxa from the Neogene deposits. The dominance of warm-temperate (A1) element and frequency of palaeotropical taxa in various parts of the profi les point to a warm-temperate climate. The results were used for reconstruction of changes in local vegetation during the sedimentation of deposits under study. The following types of fossil plant communities were distinguished: swamp forest, bush swamp, riparian forest, mixed mesophytic forest, and reed marshes. The clear and constant predominance of swamp forest pollen taxa in the total sum implies a dominant role of this type of communities in formation of the lignite deposits. The presented pollen diagrams show their strong similarity to elaborated earlier diagrams from the Polish Lowland, but in the Mużaków series marine ingression’s infl uence and presence of reed marshes (considered to be an early stage of succession on the Miocene peat-bogs) were confi rmed. KEY WORDS: pollen analysis, plant communities, palaeoecology, lignite deposits, Badenian, Miocene, Lower Silesia, Poland CONTENTS Introduction . 5 Development phases of the plant cover in the Geology . 7 Legnica region and their comparison with Material and methods . 8 other regions of the Polish Lowland . 72 General results of pollen analysis . 8 Acknowledgements . 80 List of spore, pollen and fresh-water phyto- References . 80 plankton taxa found in the studied material 11 Plates . 91 Systematic description of selected spores, pollen grains and other microremains . 14 INTRODUCTION Sporomorphs . 14 Fresh-water phytoplankton . 63 Dinophyceae . 64 Presence of lignite deposits in the Lower Fungi . 64 Silesia was the main reason for starting the sci- Abridged description of pollen diagrams . 65 entifi c interest in this region. The fi rst geologi- Reconstruction of the Neogene plant communi- cal and palaeobotanical studies were carried out ties with references to recent vegetation . 68 in the 19th century and at the beginning of the 6 20th century. Many elaborations of plant macro- The Legnica lignite deposit is a platform and micro-remains were published in the sec- type deposit that extends over a large area in ond half of 20th century (Raniecka-Bobrowska the Legnica Depression. Together with neigh- 1952, 1962, 1970, Doktorowicz-Hrebnicka bouring Ścinawa deposit they form the larg- 1954, 1956b, c, Romanowicz 1961, Stachurska est lignite-bearing area (about 15 × 30 km) et al. 1967, 1971, 1973, Sadowska 1970, 1977, in Poland (Jaroń et al. 1978, Ciuk & Piwocki 1992, 1995, Ziembińska-Tworzydło 1974, Dyjor 1990). The Legnica deposit consists of three & Sadowska 1977, Sadowska & Zastawniak (west, east and north) fi elds (Fig. 1). Total 1978, Jahn et al. 1984, Łańcucka-Środoniowa thickness of coal seams is 20.6–23.6 m (Ciuk et al. 1992, and others). 1987). Seams of the 1st, 2nd and 3rd groups form Geological studies in the Legnica region were the major part of the coal resources, and the started by Berg (1936), however, a peculiar coal is considered to be one of the best quality interest in the Tertiary sedimentary series of brown coal in Poland (Majewski 1976, Jaroń this terrain was aroused by numerous drillings et al. 1978). connected with a lignite prospecting. In 1950– The Ruja lignite deposit was discovered at 1966 in the Legnica–Lubin–Ścinawa region geo- the beginning of the nineties of 20th century. logical and prospecting works were carried out, It is considered to be a satellite deposit in and the Legnica and Ścinawa lignite deposits the Legnica–Ścinawa complex (Piwocki 1989, were discovered (Ciuk 1961a, b, 1966). The Leg- Dyląg & Kasiński 1995, Jęczmyk et al. 1997). nica deposit was documented in 1968, whereas The deposit is situated about 20 km south- the complex geological investigations connected east from Legnica (Fig. 1). The 2nd Lusatian with project of a lignite mine were carried out in seam is the main one there, at some places the the seventies of 20th century (Szulc & Burzyński 2ndA Lubin seam occurs. The 1st Henryk seam 1975). Then a series of drillings was done and consists there of a few thin horizons (Dyląg some profi les from the Legnica–Ścinawa–Lubin 1995). Legnicki region were more or less detailed The aim of the present study was a detailed palynologically elaborated (see catalogue by palynological analysis of the two profi les from Grabowska and Słodkowska 1993). the Legnica east fi eld (Legnica 41/52 and Fig. 1. Location of the Legnica lignite deposit complex (according to Jaroń et al. 1978, Wacnik & Worobiec 2001, slightly changed) 7 Legnica 33/56) and a fragment of the profi le Legnica 33/56 (depth 114.2–111.6 m) and Leg- Komorniki 97/72 from the Ruja deposit, as well nica 41/52 (depth ?129.0–125.0 m). as the reconstruction of fossil plant communi- The Lusatian seam is the main part of the ties and main features of palaeogeography and fuel resources of the Legnica lignite deposit palaeoclimate during the sedimentation of the complex due to its thickness about 20–25 m. It studied deposits. This paper is based on a PhD often lies directly on the Palaeozoic basement Thesis (Worobiec 2000). or on weathering. Because the under-coal series compensate morphological differentiation of the pre-Cainozoic basement thickness (reach- GEOLOGY ing about 120 m), equal sedimentation on large areas took place. At Legnica the Lusatian seam The Legnica–Ścinawa lignite resource com- is divided into two horizons (by sands, sandy plex is situated on the Fore-Sudetic Block, in silts and coaly clays). At Ruja it has a form of the Kaczawa zone. The Tertiary deposits of the one compact seam in central part, and 2–3 (or studied area are mainly of continental origin, more) horizons at western and northern mar- with temporary marine infl uences. For exam- gins (Jaroń et al. 1978, Dyląg 1995). Deposits ple the following Tertiary lithostratigraphic of the Lusatian seam (detritical brown coal units have been distinguished by Dyjor (1970, with xylites) occur in all studied cores: Legnica 1978, 1986) in this region: Sieroszowice series, 33/56 (depth 111.6–100.2 m), Legnica 41/52 Lubusha series with 4th Głogów lignite seam, (depth 125.0–114.2), and Komorniki 97/72. Żary series with 3rd Ścinawa seam, Silesian- The Mużaków series lies above the Lusa- Lusatian series with 2nd Lusatian seam, tian seam mainly in northern part of the Mużaków series ended by 1st Henryk seam, Fore-Sudetic Block and on the Fore-Sudetic Poznań series (divided into grey, green and Monocline (Dyjor 1978), and is correlated fl amy clays horizons), and Gozdnica series. with Pawłowice and Adamów formations These lithostratigraphic units have been used with the 2ndA Lubin group of seams (Piwocki for the Legnica region, even though, according & Ziembińska-Tworzydło 1995, 1997). This to the lithostratigraphic scheme of the Polish series consists predominantly of sandy-silt Lowland, new units (formations and mem- sediments of marine, brackish and partially bers) have been distinguished (see Piwocki swampy origin. In sandy clays and coaly silts & Ziembińska-Tworzydło 1995, 1997, and fossil traces (burrows) were found, whereas Piwocki et al. 2004). in swampy deposits lenses of brown coal and sapropelites are present. Brackish sediments NEOGENE contain glauconite and poor fauna (sponges and foraminifers) remains (Dyjor & Wróbel 1978). The oldest Neogene series in the studied area Age of the Mużaków series was defi ned as is the Lower Miocene Żary series (correlated the Middle Badenian (Piwocki & Ziembińska- with Rawicz and Gorzów formations with Żary Tworzydło 1995). At Legnica and Ścinawa this Member and 3rd Ścinawa lignite seam group). series is a few to 50 m thick. At some places The above-lying Silesian-Lusatian series (cor- the 2ndA Lubin seam occurs (Jaroń et al. 1978, related with Ścinawa and Krajenka formations Dyląg 1995). Deposits of the Mużaków series, with 2nd group of seams) shows a large vari- coaly clays, at places with impressions or ability, consisting mainly of sandy-gravel sedi- microremains of leaves, as well as sandy silts ments, intercalated by thick layers of kaolinic and sands, occur in the cores Legnica 33/56 clays, as well as silts and coal-bearing kao- (depth 100.2–76.6 m), Legnica 41/52 (depth linic clays. In the top fi ne-grained sediments, 114.2–91.8), and Komorniki 97/72. sandy clays, silts, and lignites occur (Dyjor The Mużaków series is terminated by the 1978, 1982, 1986).