Framboidal pyrite shroud confirms the 'death mask' model for moldic preservation of ediacaran soft-bodied organisms ...

• Main Author: Liu, AG
• Format: Article in Journal/Newspaper
• Language: English
• Published: Society for Sedimentary Geology 2016
• Subjects: 3709 Physical Geography and Environmental Geoscience; 31 Biological Sciences; 3103 Ecology; 37 Earth Sciences; 3705 Geology; 14 Life Below Water; Canada; Flinders; Newfoundland
• Online Access: https://dx.doi.org/10.17863/cam.36555; https://www.repository.cam.ac.uk/handle/1810/289306

Copyright © 2016, SEPM (Society for Sedimentary Geology). The mechanisms by which soft-bodied organisms were preserved in late Ediacaran deep-marine environments are revealed by petrographic and geochemical investigation of fossil-bearing surfaces from the Conception and St. John's groups (Newfoundland, Canada). Framboidal pyrite veneers are documented on fossilbearing horizons at multiple localities. The pyrite is interpreted to have formed via microbial processes in the hours to weeks following burial of benthic communities. This finding extends the 'death mask' model for Ediacaran soft-tissue preservation to deep-marine settings. Remineralization of pyrite to iron oxides and oxyhydroxides is recognized to result from recent oxidation by meteoric fluids in the shallow subsurface. Consideration of other global Ediacaran macrofossil occurrences reveals that pyrite is observed in association with Ediacaran macrofossils preserved in all four previously described styles of moldic preservation (Flinders-, ...