New information on the Ediacaran-Cambrian transition in the Vestertana Group, Finnmark, northern Norway, from trace fossils and organic-walled microfossils

Abstract

The Vestertana Group on the Digermul Peninsula, Finnmark, northern Norway, presents one of the few, potentially continuous Ediacaran– Cambrian sections in Scandinavia. Trace fossils provide the main age constraint, with the boundary traditionally placed at the base of the Breidvika Formation. Here, we provide trace-fossil evidence to show that this boundary is at least as low as the third cycle of the Manndraperelva Member, Stáhpogieddi Formation, where <i>Treptichnus pedum</i> is associated with trilobed trace fossils. Organic-walled microfossils from the same stratigraphic interval include <i>Granomarginata prima</i> and the first report from Scandinavia of <i>Cochleatina</i>. The second cycle of the Manndraperelva Member contains trace fossils, including treptichnids and <i>?Cochlichnus</i> isp. tentatively interpreted as latest Ediacaran. Reports of palaeopascichnids suggest a late Ediacaran age for the first cycle. The age of lower parts of the Stáhpogieddi Formation is poorly constrained but discoidal Ediacara-type fossils, vendotaenids, and possible simple trace fossils, suggest that the middle part of the Innerelva Member is younger than c. 560 Ma.