NJG81-2-04
2001
The Ordovician Billingen/Volkhov boundrary interval (Arenig) at Lava Rive, northwestern Russia
81
2
pp. 161-168
82-519-1694-1

A detailed study of the con odont distribution within the condensed carbonate beds around the boundary of Billingen and Volkhov Stages (Lower Ordovician, Arenig) in northwestern Russia confirms the presence of a continuous succession of conodont biownes recognized in contemporaneous sequences in Scandinavia. The Baltoniodus triangularis and Microzarkodina sp. A zones are reported for the first time from East Baltica,where carbonates of this interval underwent extensive bioturbation and are characterized by a number of closely spaced and distinctive glauconitic hardground surfaces. It has been revealed that the distribution of conodont elements around the hardground surfaces is strongly affected by bioturbation.

0029-196X.
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