Palynostratigraphic reassessment of the Late Devonian of Bjørnøya, Svalbard

• Autor(a) principal: Lopes, Gilda
• Data de Publicação: 2021
• Outros Autores: Mangerud, Gunn, Clayton, Geoff, Vigran, Jorunn Os
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/16761
• topic: Miospores; Paleoenvironments; Famennian; Røedvika formation; Billefjorden group; Norwegian Arctic

A comprehensive study of the Late Devonian palynostratigraphy of Bjørnøya, Svalbard Archipelago is presented.A total of 61 samples collected from 10 outcrops located along the eastern coast of the island were analyzed forpalynology yielding a mid- to latest Famennian age. A reassessment of the existing palynostratigraphy of the UrsaSandstone Unit of the Røedvika Formation was undertaken. As no independent age control exists for this succes-sion, the palynological assemblages were correlated to well-calibrated palynological zonations from the Easternand Western Europe. The middle to upper part of the Vesalstranda Member and the Kapp Levin Member wereassigned a mid- to late Famennian age (CVa to VF biozones), and the middle to lower-upper part of the TunheimMember was dated as latest Famennian in age (LL to LN biozones). For thefirst time, a palynological age wasassignedto the upperpart ofthe KappLevin Member. Correlation with other Arctic areas show close resemblanceto Late Devonian assemblages from Europe and the Arctic region. However, differences in the stratigraphicalranges of several taxa were identified. In terms of Late Devonian paleophytogeographic provinces the miosporeassemblages are assigned to the Northern EuroamericanCornispora varicornataRealm for the mid-Famennian. Amore cosmopolitan trend was recognized for the latest Famennian (Strunian), with assemblages including abun-dantRetispora lepidophyta. The paleobotanical affinities of the palynomorphs reveal aflora of lycopods andprogymnosperms occupying this area during the Late Devonian, withRetispora lepidophytabecoming a commonelement in the latest Famennian.