MagnetoSusceptibility Event and Cyclostratigraphy (MSEC) of the Eifelian- Givetian GSSP and associated boundary sequences in north Africa and Europe

摘要

Magnetosusceptibility event and cyclostratigraphy (MSEC) is used to define magnetic susceptibility (MS) signatures for the Eifelian-Givetian GSSP in southern Morocco and four other Eifelian-Givetian boundary sequences in Morocco, southern France, and the Czech Republic. MSEC data from the GSSP are used to identify nine first-order isochronous MSEC events for chronocorrelation. MSEC data clearly define a new abiotic Late Eifelian MSEC Event that immediately precedes the Eifelian-Givetian boundary and encompasses the biotic Kacdk and otomari Events. The MSEC event begins in the upper Tortodus kockelianus kockelianus Zone and ends in the upper Polygnathus ensensis Zone. This Event occurs in the same stratigraphic position in the boundary sequences studied. The characteristics of the Late Eifelian MSEC Event are those of a prolonged high stand in global sea level.