Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Volumina Jurassica

1 2006

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Bathonian ammonites from the Polish Tatras

Galacz A., Matyja B.

Volumina Jurassica

2006

Vol. 4, no. 1

162-162

In the sedimentary sequence of the Polish High Tatras, thin limestone beds with Middle Jurassic, mainly Bathonian fossils have been reported. The best known of these occurrences is that of Wielka Âwistówka Cirques in the Mi´tusia Valley with extremely rich ammonite fauna which became famous for the classic monographs of Passendorfer in 1935 and 1938. The fauna occurs in a condensed bed overlying with considerable hiatus the Middle Triassic shallow-water carbonates, and is covered by Upper Jurassic pelagic limestone. The 8-12 cm thick bed yielded nautiloids, belemnites, ammonites and brachiopods in great profusion, and less commonly other molluscs (bivalves and gastropods). The revision of the ammonite fauna in the collections of Passendorfer indicated that most of the forms is typical of the higher Middle Bathonian Bremeri Zone, with the rich representation of the zonal index and other diagnostic forms, e.g. Prohecticoceras ochraceum, Bullatimorphites eszterensis. Within the perisphinctids, Procerites is dominant and Wagnericeras is rarer which could indicate the lower part of the Bremeri Zone. As interesting rarities, Phlycticeras, Oecoptychius, Thraxites, etc. also appear. However, the collections contain some macrocephalitids and rare Hecticoceras suggesting the presence of the Lower Callovian. While preservational differences cannot be seen between the Bathonian and Callovian fossils, and the recent state of the Wielka Âwistówka exposure did not show this, the best explanation is to suppose an occurrence of a thin, intermittent Callovian layer in between the Bathonian and Upper Jurassic beds as the source of these stratigraphically younger ammonites in the collections. The ammonite fauna is dominated by suborder Ammonitina (66.6%) of which nearly half belongs to the Perisphinctidae, and phylloceratids are represented 32%. This is a faunal composition very close to those from other Bathonian condensed ammonite beds occurring in the Carpathian-Pannon region (e.g. Swinitza in the Southern Carpathians, Villány in South Hungary).