Mitchell, R.L. orcid.org/0000-0002-6328-3998, Strullu-Derrien, C. and Kenrick, P. (2019) Biologically mediated weathering in modern cryptogamic ground covers and the early Paleozoic fossil record. Journal of the Geological Society, 176 (3). pp. 430-439. ISSN 0016-7649
Abstract
Specific micro-weathering features and biochemically derived residues formed by living organisms can be used as biomarkers to infer the presence of biological communities within sedimentary units of ancient ecosystems. We examined basaltic soil minerals from modern cryptogamic ground covers (CGCs) in Iceland and compared these with two early Paleozoic fossil systems. Nine biologically mediated weathering features (BWFs) were identified in modern soils including micron-scale surface trenching and penetrative tunnels, which are attributed to the actions of bacteria, fungi and exudates. Specific BWFs are associated with Fe residues, and with Fe-rich bio-precipitated nodules. Further, putative comparable features and Fe enrichment are identified in palaeosols from the late Silurian (Llansteffan, south Wales) and the Early Devonian (Rhynie chert, Scotland). Although we are cautious about attributing biological affinity to individual isolated features, our results demonstrate the potential of using multiple BWF types as a collective together with their chemical signatures as new proxies to understand community structure and interactions in early terrestrial ecosystems. This new information is the first evidence of interactions between ancient CGC-like organisms and substrate or soil inorganic components in the fossil record, and demonstrates the ability of CGC-like biospheres to contribute to mineral weathering, soil development and biogeochemical cycling during the early Paleozoic.
Supplementary material: Fieldwork geomorphological information and triplot SEM-EDS data are available at https://doi.org/10.6084/m9.figshare.c.4373717
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Geological Society Publishing House. This is an author-produced version of a paper subsequently published in Journal of the Geological Society. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 28 May 2020 15:19 |
Last Modified: | 28 May 2020 15:19 |
Status: | Published |
Publisher: | Geological Society of London |
Refereed: | Yes |
Identification Number: | 10.1144/jgs2018-191 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:161303 |