Blanowice Formation

The Blanowice Formation is a geologic formation in Częstochowa, Poland. It is late Pliensbachian-Lowermost Toarcian age. Plant fossils have been recovered from this formation. Along with the Drzewica Formation is part of the Depositional sequence IV-VII of the late lower Jurassic Polish Basin. Deposits of sequences IV, V, VI and VII make up the Blanowice Formation, being all four sequences are of Pliensbachian age, documented by megaspores (Horstisporites). On the upper strata, “sub-coal beds" cover the sequence VII-lower VIII (Pliensbachian-Toarcian transition), while the uppermost part of VIII is identified with the Ciechocinek Formation. The Blanowice Formation has been known for decades thanks to the abundant plant fossils and plant roots, but mostly due to the Blanowice Brown Coals, where the oldest Biomolecules found worldwide have been recovered. The Mrzygłód mine dinocyst assemblage is taxonomically undiversified, containing specimens that are good age indicators allowing relatively precise suggestion of its age. Luehndea spinosa, with a single recovered specimen spans between the Late Pliensbachian (Margaritaus) to the Lowermost Toarcian (Tenuicostatum). Other ocal dinocysts such as Mendicodinium range Late Pliensbachian–Aalenian, a wider stratigraphic range. The lower part of the formation is coeval in age with the Gielniów Formation and Drzewica Formation (Southern and central Poland), Lobez Formation and Komorowo Formation (Pomerania), Olsztyn Formation (Baltic German-Polish transition), the lower part of the Rydeback Member of the Rya Formation (Southern Sweden), lower Fjerritslev or Gassum Formation (Danish Basin), lower and middle Sorthat Formation (Bornholm), Neringa Formation (Lithuania). The upper part is coeval with the lowermost upper Rydeback Member, upper Gassum Formation and lower Lava Formation (Lithuania).