中国科学院南京地质古生物研究所机构知识库

The Cambrian succession of the Tingskullen drill core from northern Oland comprises Cambrian Series 2 and Miaolingian (Wulivan Stage) siliciclastic strata. The major portion of the succession is represented by the Miaolingian Borgholm Formation, which, in ascending order, is subdivided into the Mossberga, Barstad and Aleklinta members. The Aleklinta Member is barren of body fossils, whereas the Mossberga and BArstad members are moderately to highly fossiliferous and biostratigraphically reasonably well constrained. Trilobites and agnostoids from the BArstad Member are indicative of the Acadoparadoxides pin us Zone. The Mossberga Member has not yielded any zonal guide fossils but is tentatively assigned to the Eccaparadoxides insularis Zone. A delta C-13(org) curve throughout the Borgholm Formation shows a general positive trend up-section without any distinctive excursion, suggesting that the Wulivan Acadoparadoxides (Baltoparadoxides) oelandicus Superzone (the 'Oelandicus beds') of Oland is younger than the negative Redlichiid-Olenellid Extinction Carbon isotope Excursion (ROECE), which is known from near the top of Stage 4 and close to the traditional 'Lower-Middle Cambrian boundary' in several parts of the world.