Atokan

Atokan

[ə′tō·kən]
(geology)
A North American provincial series in lower Middle Pennsylvanian geologic time, above Morrowan, below Desmoinesian.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
We think that the complex relationships that exist between Idiognathodus and Streptognathodus must be investigated from the inception of these morphologies, from Morrowan and Atokan time, and that all troughed and partially troughed forms prior to Missourian should be excluded from Streptognathodus.
The late Atokan (Moscovian-Pennsylvanian) chaetetid accumulations of Sierra Agua Verde, Sonora (NW Mexico): composition, facies and paleoenvironmental signals, p.
Their topics include Lower Cambrian shelled phosphorites from the northern Montaigne Noire in France, Siluro-Devonian alpine reefs and pavements, a late Atokan regional encrinite in the Sierra Agua Verde in northwestern Mexico, and whether the distribution of tabulae in tabulates can be used to estimate palaeo-environmental changes.