Framboidal pyrite shroud confirms the ‘death mask' model for moldic preservation of ediacaran soft-bodied organisms—a reply
Thin, laterally extensive veneers of framboidal pyrite on fossiliferous bedding planes in eastern Newfoundland, Canada, provide evidence for post-burial microbially mediated pyritization of the seafloor in the late Ediacaran Period (Liu 2016). Pyrite is inferred to have formed on the external surfac...
Published in: | PALAIOS |
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Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
SEPM (Society of Sedimentary Geology)
2017
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Subjects: | |
Online Access: | http://eprints.esc.cam.ac.uk/3862/ http://eprints.esc.cam.ac.uk/3862/1/197.full.pdf http://eprints.esc.cam.ac.uk/3862/2/PALO_Retallack%20reply%20on%20pyrite%20shroud%20post%20revisions%20RESUBMITTED.pdf https://doi.org/10.2110/palo.2016.104 |
Summary: | Thin, laterally extensive veneers of framboidal pyrite on fossiliferous bedding planes in eastern Newfoundland, Canada, provide evidence for post-burial microbially mediated pyritization of the seafloor in the late Ediacaran Period (Liu 2016). Pyrite is inferred to have formed on the external surfaces of soft-bodied organisms and microbial matgrounds as a result of bacterial sulfate reduction, consistent with the ‘death mask' taphonomic model for Ediacaran moldic preservation (Gehling 1999). Retallack (2017) accepts the evidence presented by Liu (2016) for early diagenetic pyritization of bedding planes in Newfoundland, and seems to offer at least tacit acceptance of evidence for modern oxidation of that pyrite, its widespread occurrence in global Ediacaran localities, and the potential influence of sedimentary pyrite burial on global Ediacaran oxygen concentrations. However, Retallack questions whether the presence of such pyrite veneers can be taken to demonstrate the ‘death mask' taphonomic model, and specifically queries the source of the observed pyrite. |
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