Commune: Barcin (pow. żniński, woj. kujawsko-pomorskie)

Framework element or context represented:
Shallow-marine facies and ubiquitous fossils.

Primary geological/geomorphological interest:
Fossiliferous biohermal complex of Upper Jurassic age.

Comparative assessment justification:
Wide spectrum of diverse facies of the complex structure, from the bioherm core, through slopes moving down into basin depths.

Protection status and accessibility:
Protection proposed, accessibility due to quarry permission.

Character of site: Abandoned parts of the quarry.

Area: 10 ha

Altitude: 69-90 m a.s.l.

Lithology: other evaporite rocks, other organic rocks

Discipline: Palaeobiology, Palaeoenvironment, Stratigraphy of Phanerozoic

Process Age: *all periods

Bedrock Age: Jurassic, *all periods

Description of primary interest:
The Middle to Late Jurassic (uppermost Oxfordian) sequence of a cyanobacterial-sponge buildup and its flanks diverging into muddy basin facies has developed atop salt-domed (halokinetic) anticline rising along the Mid-Polish Anticlinorium, in the Kujawy (Couiavia) region of north-Central Poland. The two huge quarries, Bielawy and Wapienno, over 1 km long and over 100 m deep, make easy access to particular facies of this carbonate buildup, some of which yield ubiquitous fossils of various types (sponges, polychaetes, brachiopods, ammonites, crinoids, and echinoids). Sedimentary features and eco-taphonomy of diverse biota indicate the complex structure of the buildup having been raised simultaneously with upheaval of a salt diapire in the basement. Easy insight into ancient reef-like biohermal complex.


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