Back to search
Viira, 2008

Conodont biostratigraphy in the Middle-Upper Ordovician boundary beds of Estonia

Viira, V.
PDF
Year2008
JournalEstonian Journal of Earth Sciences
Volume57
Number1
Pages23-38
Typearticle in journal
Figures8
OpenAccess
LitsentsCC BY 4.0
Estonian author
LanguageEnglish
Id1190

Abstract

Conodonts of the uppermost Uhaku, the Kukruse, and the lower Haljala stages (uppermost Darriwilian and lower Sandbian) of Estonia are discussed. The distribution of conodonts within the Pygodus serra, P. anserinus, and Amorphognathus tvaerensis zones is considered on the basis of 2 outcrop and 15 drill core sections. Judging by the Global Stratotype Section, Fågelsång, Sweden, the base of the Upper Ordovician Series should be lower than the first appearance of A. tvaerensis. The Estonian material shows that elements of A. tvaerensis from the lowermost range of the species are of a morphotype similar to A. inaequalis. It is proposed that the A. inaequalis Subzone be upgraded to the A. inaequalis Zone. The best level for the Middle–Upper Ordovician boundary in Estonia is at the lower boundary of the Kukruse Stage below the appearance of A. tvaerensis and/or A. inaequalis.

Remarks

Error on Fig. 6 caption -- L and M are exchanged, 6M belongs to E. elongatus and 6L B. gerdae.
Last change: 12.6.2022
KIKNATARCSARVTÜ Loodusmuuseumi geokogudEesti Loodusmuuseumi geoloogia osakond
All materials in the portal are for free usage according to CC BY-SA , unless indiated otherwise.
Portal is part of natianal research infrastructure and geoscience data platform SARV, hosted by TalTech.
Open Book icon by Icons8.