Duration of ammonite zones and characteristic Jurassic fossil taxa from the Pliensbachian–Aalenian successions of Bulgaria-Reference-Cited by-同舟云学术

Duration of ammonite zones and characteristic Jurassic fossil taxa from the Pliensbachian–Aalenian successions of Bulgaria

Published:2023-12 Issue:3 Volume:84 Page:185-188
ISSN:0007-3938
Container-title:Review of the Bulgarian Geological Society
language:en
Short-container-title:Rev. Bulg. Geol. Soc.

Author:

Metodiev Lubomir,Dochev Docho,Georgieva Milena,Stoylkova Tania,Koleva-Rekalova Elena,Dimitrov Iliya,Savov Ivan P.

Abstract

The relative durations of ammonite biozones and selected ammonite taxa, as well as some bioevents associated with coeval Lower–Middle Jurassic benthic taxa are represented herein. Based on linked Sr-isotope data, we found a notable difference in the time spans of the zones and in the relative longevity of the guiding ammonite genera around the Pliensbachian/Toarcian (P/T) boundary. The last occurrences of the well-known late Pliensbachian bivalve taxa Gryphaea gigantea and Pseudopecten aequivalvis were dated at 184 Ma and 183.8 Ma, respectively. Recently defined Toarcian–Aalenian autochtonous brachiopod taxa (Bulgariarhynchia and Capillirhynchia brezenensis) were found to have significant taxonomic durations (2 Ma and 5 Ma). The Sr-isotope data also revealed ~2 Ma duration of seawater warming and 0.2 Ma fossil hiatus around the P/T boundary.

Publisher

Bulgarian Geological Society

Subject

General Medicine

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