Blanowice Formation

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Sub-units
  • Siewierz Area
  • Zawiercie
  • Wysoka mine
  • Blanowice Brown Coals
Blanowice Formation
Stratigraphic range: Late Pliensbachian to Lower Toarcian
~185–180 Ma
[1]
TypeGeological formation
Unit ofKamienna Group[1]
Sub-units
  • Siewierz Area
  • Zawiercie
  • Wysoka mine
  • Blanowice Brown Coals
UnderliesCiechocinek Formation, Borucice Formation[1]
OverliesZagaje, Lobez, Ostrowiec & Gielniów Formations
ThicknessUp to ~42.0 m (137.8 ft)[1]
Lithology
PrimarySandstones, subordinately Mudstones, Heteroliths y Coal seams.
OtherSeveral types of heteroliths and mudstones
Location
RegionCzęstochowa, Southern Poland
CountryPoland
ExtentCzêstochowa region[1]
Type section
Named forBlanowice, a town from Zawiercie, Poland
Named byZnosko (as an informal unit)[2]
Blanowice Formation is located in Poland
Blanowice Formation
Blanowice Formation (Poland)

The Blanowice Formation is a geologic formation in Częstochowa, Poland. It is late Pliensbachian-Lowermost Toarcian age.[1][2][3] Plant fossils have been recovered from this formation.[1] Along with the Drzewica Formation is part of the Depositional sequence IV-VII of the late lower Jurassic Polish Basin.[1] 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).[1] 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.[1] 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,[4][5] where the oldest Biomolecules found worldwide have been recovered.[6] The Mrzygłód mine dinocyst assemblage is taxonomically undiversified, containing specimens that are good age indicators allowing relatively precise suggestion of its age.[3] Luehndea spinosa, with a single recovered specimen spans between the Late Pliensbachian (Margaritaus) to the Lowermost Toarcian (Tenuicostatum). Other ocal[clarification needed] dinocysts such as Mendicodinium range Late Pliensbachian–Aalenian, a wider stratigraphic range.[3] 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).[1] The upper part is coeval with the lowermost upper Rydeback Member, upper Gassum Formation and lower Lava Formation (Lithuania).[1]

"Zygmunt" mine, the largest mining group working with the Blanowice Coals.

The local Mesozoic brown Coal is composed by Lignite of Lower Jurassic age, known as the Blanowice Coal. Increased carbon-bearing capacity, locally present in the profile of the Upper Forest land sediments, was the basis for the development coal mining in this area in the years 1818–1959. The mining center at that time was concentrated in the vicinity of Poręba near Zawiercie, as well as in a dozen other towns (Sprawowice, Blanowice, Łazy, Siewierz). Its basis was shallow exploitation a coal seam with a thickness of up to 2.0 m.[7][8] Occurrence of Blanowice Coals in Jurassic outcrops between Częstochowa and Zawiercie was known for a long time. Already in the 1890s, they were mined on a small scale in the vicinity of Blanowice, being described since the start of the exploitation.[9] After 1796 on Siewiersk was reported hard coal, the first outcrop of the main Blanowice Fm coal. The mining of Blanowice Coals developed specially in the 1920s and 1930s, where major discoveries were reported.[10] This coals were exploited on small exploitations, where various minor mines recovered the coal seams.[8] The "Zygmunt" mine, operating at the turn of the 1920s and 1930s, was one of the largest. Annual production, as shown in official documents, it exceeded the total output from other mines many times.[8]

Stratigraphy

Biota

References

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