Homotryblium-dominated Eocene dinoflagellate cyst assemblages from Middle Miocene (Badenian) glauconitic sands at Lipowiec (Roztocze, SE Poland)

Abstract

1 Pol ish Acad emy of Sci ences, In sti tute of Geo log i cal Sci ences, Senacka 1, 31-002 Kraków, Po land Gedl, P., 2016. Homotryblium-dom i nated Eocene dinoflagellate cyst as sem blages from Mid dle Mio cene (Badenian) glauconitic sands at Lipowiec (Roztocze, SE Po land). Geo log i cal Quar terly, 60 (2): 461-472, doi: 10.7306/gq.1289A sec tion over 20 m thick of the basal Mid dle Mio cene suc ces sion ex posed at Lipowiec (Roztocze, SE Po land) was stud ied for palynology. Thir teen sam ples were col lected from quartz and glauconitic-quartz sands and thin clay lay ers. Sand samples were bar ren but clay sam ples yielded dinoflagellate cysts. Their as sem blages con sist of re worked Paleogene spec imens dom i nated by the Homotryblium floripes com plex (H. floripes and mor pho log i cally sim i lar H. plectilum and H. vallum). The pres ence of re worked Paleogene spec i mens in di cates in tense ero sion of ma rine Paleogene strata dur ing ini tial stages of the Mid dle Mio cene trans gres sion at Roztocze. Anal y sis of strati graphi cal ranges of re worked dinoflagellate cysts and com par i son with their oc cur rences in known epicontinental Paleogene sites of SE Po land sug gest an Up per Eocene age of the washed-out strata. The tax o nomic com po si tion of the as sem blages de scribed sug gests that the Up per Eocene de pos its ac cu mu lated in a near-shore, la goonal embayment char ac ter ized pre sum ably by oligotrophic wa ters of slightly in creased salin ity. A high pro por tion of the Homotryblium floripes com plex is also char ac ter is tic of re worked as sem blages found in younger Mio cene strata of neigh bour ing ex po sures in Roztocze, which in di cates wide spread Eocene la goonal en vi ron ments in this part of Roztocze. Co eval Eocene strata from the east ern part of Roztocze and from the Carpathian Foredeep show dif ferent tax o nomic com po si tions sug gest ing var ied sed i men tary set tings dur ing Eocene trans gres sion in this re gion. These differ ences re flect vari able amounts of fresh wa ter in flu ence re sult ing in a range of en vi ron ments that ranged from oligotrophic to brack ish.

Palynology of the deep structures of the Carpathian Foredeep (3,950– 5,467 m) at the front of Carpathian overthrust, the NS-1 Borehole, SE Poland

“…Correlation of the lower part of the autochthonous Miocene in the NS-1 Borehole with the Skawina/Baranów beds of the Foredeep Basin, is further supported by the taxonomical similarity of the dinoflagellate cyst assemblages (e.g., Gedl, 1995Gedl, , 1996Gedl, , 1999. Their composition and predominance over terrestrial elements shows that the Foredeep Basin during the early Badenian in Poland was fully marine, characterized by similar sedimentary conditions, being a vast basin with predominantly pelagic deposition.…”

“…This species is known to have appeared during this time interval in the mid-latitudes of the Northern Hemisphere mid-latitudes (Williams et al, 2004). U. aquaeductum is typical only for the lower Badenian sub-evaporitic strata of the Carpathian Foredeep (e.g., Gedl, 1996Gedl, , 1998Gedl, , 1999Peryt and Gedl, 2010). It does not occur in the upper Badenian strata overlying the evaporitic series (e.g., Peryt et al, 2014).…”

“…also could indicate the earliest Miocene. The highest occurrences of this particular genus in the Miocene; Stover et al, 1996;Williams et al, 2004; see also Gedl, 2016) could be in situ. Better preserved specimens, representing Rhombodinium and Enneadocysta, could have been recycled from Paleogene strata in clasts, assuring their better preservation.…”

“…All of these are important parts of the Miocene dinoflagellate cyst assemblages from the Carpathian Foredeep (e.g., Gedl, 1996Gedl, , 1998Gedl, , 1999. Many other taxa, which are typical for the Paleogene, i.a., Areosphaeridium, Glaphyrocysta, Enneadocysta, Areoligera, Thalassiphora, Phthanoperidinium or Rhombodinium, are missing.…”

“…The lower part of the autochthonous Miocene sequence studied is correlated by means of dinoflagellate cyst assemblages with the upper part of the NN5 and the lower part of the NN6 calcareous nannoplankton zones, on the basis of the presence of the stratigraphically important Unipontodinium aquaeductum (e.g., Gedl, 1996Gedl, , 1998Gedl, , 1999. This age interval corresponds in the Polish sector of the Carpathian Foredeep to the Skawina Beds and the Baranów Beds (and their local counterparts, such as the Korytnica Clays), in which calcareous nannoplankton allow their correlation with NN5 and NN6 (Martini, 1977;Dudziak and Łuczkowska, 1992;Gaździcka, 1994) and with the Paratethyan stage, the Badenian (upper Langhian to lower Serravalian, according to Lourens et al, 2004).…”