The Mid-Tournaisian event in the Northern Urals and conodont dynamics

Abstract

The distribution of conodonts across several sections in the Northern Urals is documented for the interval spanning the Carboniferous Mid-Tournaisian (‘Lower Alum Shale’) global event. In the Northern Urals the event interval is represented by cherty sediments with layers of clastic limestone. The event interval comprises the uppermost part of the duplicata-sandbergi Conodont Zone and the lower part of the quadruplicata Conodont Zone, and is marked by an extensive radiation of conodonts. At this interval a number of siphonodellids, pseudopolygnathids. and a new species of primitive Eotaphrus appear. This new species ( Eotaphrus simplex sp. nov.) is described herein. Although some conodont taxa became extinct at the event level, the predominant conodont radiation is in contrast to the worldwide extinction of goniatite faunas previously described. The abundant and characteristic post-event conodont fauna has good potential for correlation of the Mid-Tournaisian boundary in deep-water facies both in the Northern Urals and worldwide.