Upper Devonian of Western Pomerania

Hanna Matyja

Abstract


Within the generally carbonate and mixed carbonate-siliciclastic sequence pierced by deep boreholes, 21 conodont zones are recognized from the Frasnian punctata Zone up to the lower Tournaisian sandbergi Zone in Western Pomerania, northwestern Poland. Four Famennian conodont species are established as new: Polygnathus limbatus sp. n., Polygnathus pomeranicus sp. n., Polygnathus praecursor sp. n., and Alternognathus costatiformis sp. n. Lateral relationship of litho- and biofacies as well as their vertical succession are recognized within the Late Devonian sedimentary environments. Six conodont biofacies (paImatolepid-polygnathid, polygnathid-palmatolepid, icriodid-polygnathid, polygnathid, polygnathid-bispathodid, and bispathodid) and some mixed conodont biofacies are documented in settings ranging from offshore pelagic to shallow nearshore. The distribution of the Late Devonian litho- and biofacies within the epicratonic Pomeranian sea was influenced by the location of the hinterland to the north (Fennoscandian High) and to the east (Mazurian and/or Byelorussian High) which controlled a north- and eastwardly sea shallowing. The Late Devonian history of Western Pomerania underwent evolution from extremely shallow water and coastal environments in the earliest Frasnian, through deeper environments during the rest of the Frasnian and early Famennian up to the rhomboidea Chron. The presence of Famennian stromatoporoid-coral-crinoid-bryozoan buildups is noticeable in the Early and Middle marginifera Chrons. Extensive shallow water and coastal environments reappeared in the late Famennian, precisely since the Latest marginifera Chron up to the Middle expansa Chron. At the end of the Famennian, beginning with the Late expansa Chron, an open sea environment became prevalent almost over the whole area and continued up to the early Tournaisian. A sequence of 13 events, both eustatic sea-level changes and epeiric movements, as well as those of biotic nature, is revealed and dated in terms of the worldwide standard conodont zonation.


Full Text:

PDF

Refbacks

  • There are currently no refbacks.