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Hints, O. & Nõlvak, 1999a

Proposal for the lower boundary-stratotype of the Keila Regional Stage (Upper Ordovician)

Hints, O., Nõlvak, J.
JournalProceedings of the Estonian Academy of Sciences. Geology
Typearticle in journal
LitsentsCC BY 4.0
Estonian author


According to the latest view on stratigraphy, chronostratigraphic units, stages inclusive, can be unambiguously defined only by their lower boundary-stratotypes. The Ordovician regional stages of Estonia are mostly distinguished based on their content rather than their boundaries, and in many cases lack appropriate lower boundary-stratotypes. In this study we propose the boundary-stratotype for the Keila Regional Stage. The lower boundary of the Keila Stage has commonly been understood as the base of the Kinnekulle K-bentonite. The suggested stratotype section and point is defined as the base of the Kinnekulle K-bentonite in a subsurface tunnel at Pääsküla Hillock, south of Tallinn, North Estonia. This K-bentonite bed can be widely traced in Baltoscandia, and the approximately coeval Millbrig K-bentonite is widespread in North America. Several microfossils could also be used to distinguish the lower boundary of the Keila Stage within Baltoscandia.

Last change: 25.3.2023
KIKNATARCSARVTÜ Loodusmuuseumi geokogudEesti Loodusmuuseumi geoloogia osakond
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