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The AAPG/Datapages Combined Publications Database

CSPG Special Publications

Abstract


Devonian of the World: Proceedings of the 2nd International Symposium on the Devonian System — Memoir 14, Volume III: Paleontology, Paleoecology and Biostratigraphy, 1988
Pages 179-191
Global Events and Boundaries

Proposal and Comment on the Definition of Emsian

Chang-min Yu, Yi-ping Ruan

Abstract

A general review of the Lower Devonian sections in South and Southwestern China is presented. After considering the stratigraphic development of the Lower Devonian in the classical Ardenno-Rheinish and Barrandian areas, a new level at the base of the Nowakia praecursor Zone, or approximately at the base of the dehiscens - perbonus conodont zone is recommended for the base of the Emsian. Since the duration of the Emsian, as recently correlated, was much greater than that of Pragian and Lochkovian combined, it is preferable to subdivide the Lower Devonian into four stages rather than three. If Emsian is retained as a chronostratigraphic unit, it would be better defined so that it is restricted to the original conception of the upper Emsian.


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