Cherns, Lesley ![]() |
Abstract
Early diagenetic dissolution of skeletal carbonate in environments from seafloor to shallow burial has the potential to skew the marine fossil record of aragonitic shells, particularly molluscs. Taphonomic windows leading to the preservation of labile skeletal components include relatively rare occurrences of early mineral replacement by silica (skeletal lagerstätten). Another, much more frequent process is event deposition where dissolution is halted by rapid burial of shells. Shell plasters form in basinal mud or low energy lagoonal environments during temporary dysoxic episodes, such as are caused by algal blooms. Preservation potential for aragonitic fossils may be enhanced by early cementation during shallow burial (hardgrounds) that protects the delicate dissolution moulds from destruction by bioturbation, or in high energy shoal environments where the drive for microbial dissolution is reduced. A data-based environmental model summarizes the main taphonomic zones, and illustrates significant taphonomic bias against aragonitic shells in lower energy settings of platform interiors and mid-outer ramps/shelves. The temporal distribution of various taphonomic windows shows the limited occurrence of silicified faunas, while the nature and extent of shell beds also change, but there is no obvious correlation with periods of 'calcite' and 'aragonite seas'.
Item Type: | Book Section |
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Date Type: | Publication |
Status: | Published |
Schools: | Earth and Environmental Sciences |
Subjects: | G Geography. Anthropology. Recreation > GC Oceanography Q Science > QE Geology |
Publisher: | Springer |
ISBN: | 9789048186433 |
ISSN: | 0275-0120 |
Related URLs: | |
Last Modified: | 02 Dec 2022 12:17 |
URI: | https://orca.cardiff.ac.uk/id/eprint/10025 |
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