Article: Vendian microfossils in metasedimentary cherts of the Scotia Group, Prins Karls Forland, Svalbard
Publication: Palaeontology
Volume:
35
Part:
4
Publication Date:
November
1992
Page(s):
751
–
774
Author(s):
Andrew H. Knoll
Abstract
Sedimentary rocks of the Scotia Group, Prins Karls Forland, Svalbard, have been metamorphosed to lower greenschist facies. Yet Scotia chert nodules contain abundant organic-walled microfossils belonging to at least seventeen taxa. Their black colour indicates that the fossils underwent substantial thermal alteration. However, it is suggested that preservation in a matrix of early diagenetic silica shielded them from the most destructive mechanical and chemical effects of metamorphism. Microbial mats and large acanthomorphic acritarchs suggest a coastal marine depositional environment; the acritarchs further indicate an early Vendian age for the sediments. The Scotia fossils bear a close resemblance to assemblages described from the Doushantuo Formation, China and elsewhere, demonstrating the broad geographical distribution of biostratigraphically important Vendian taxa. Briaretts and Echinosphaeridium are described as new genera; Briareus borealis is described as a new species, while Echinosphaeridium maximum is proposed as a new combination.