Upper Jurassic coral assemblages of the Central Polish Uplands

Ewa Roniewicz, Piotr Roniewicz


The Upper Jurassic coral assemblage of the Holy Cross Mts and Polish Jura Chain are composed of: a) foliaceous and submassive colonies, b) branching colonies and c) massive subspherical colonies. The character of corals and associated fauna and flora, as well as deposits in which the assemblages occur indicate a very shallow-water environment. The character of this environment and the process of sedimentation, which accompanied the growth, indicate i.a. that the assemblages were formed by the accretion of colonies at a rate equaling that of the sedimentation. An increase in the rate of sedimentation caused the end of their development. The assemblages discussed did not supply detrital material to the sediment and did not exert a decisive influence on the course of sedimentation, which makes them similar to Recent patch reefs of the Bahamas.

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