An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process
Abstract Coccolith dissolution together with post‐mortem morphological features are immensely important phenomena that can affect assemblage compositions, complicate taxonomic identification as well as provide valuable palaeoenvironmental insights. This study summarizes the effects of pH oscillation...
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Online Access: | http://dx.doi.org/10.1111/gbi.12528 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12528 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/gbi.12528 |
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crwiley:10.1111/gbi.12528 2024-06-23T07:52:04+00:00 An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process Holcová, Katarína Scheiner, Filip Univerzita Karlova v Praze Grantová Agentura České Republiky 2022 http://dx.doi.org/10.1111/gbi.12528 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12528 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/gbi.12528 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Geobiology volume 21, issue 2, page 193-209 ISSN 1472-4677 1472-4669 journal-article 2022 crwiley https://doi.org/10.1111/gbi.12528 2024-06-04T06:42:08Z Abstract Coccolith dissolution together with post‐mortem morphological features are immensely important phenomena that can affect assemblage compositions, complicate taxonomic identification as well as provide valuable palaeoenvironmental insights. This study summarizes the effects of pH oscillations on post‐mortem coccolith morphologies and the abundances and compositions of calcareous nannoplankton assemblages in three distinct types of material—(i) Cretaceous chalk, (ii) Miocene marls, and (iii) late Holocene calcareous ooze. Two independent experimental runs within a semi‐enclosed system setting were realized to observe assemblage alterations. One experiment was realized with the presence of bacteria and, in contrast, the second one inhibited their potential effect on the studied system. The pH was gradually decreased within the range of 8.3–6.4 using a reaction of CO 2 with H 2 O forming weak carbonic acid (H 2 CO 3 ), thereby affecting []. Further, a subsequent overgrowth study was carried out during spontaneous degassing accompanied by a gradual pH rise. The experiment revealed that the process and intensity of coccolith corrosion and subsequent overgrowth build‐ups are influenced by a plethora of different factors such as (i) pH and associated seawater chemistry, (ii) mineral composition of the sediment, (iii) the presence of coccoliths within a protective substrate (faecal pellets, pores, pits), and (iv) the presence/absence of bacteria. Nannoplankton assemblages with corroded coccoliths or with coccoliths with overgrowth build‐ups showed that the observed relative abundances of taxa experienced alteration from the original compositions. Additionally, extreme pH oscillations may result in enhanced morphological changes that make coccoliths unidentifiable structures, and might even evoke the absence of coccoliths in the fossil record. Article in Journal/Newspaper Carbonic acid Wiley Online Library Geobiology 21 2 193 209 |
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Wiley Online Library |
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crwiley |
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English |
description |
Abstract Coccolith dissolution together with post‐mortem morphological features are immensely important phenomena that can affect assemblage compositions, complicate taxonomic identification as well as provide valuable palaeoenvironmental insights. This study summarizes the effects of pH oscillations on post‐mortem coccolith morphologies and the abundances and compositions of calcareous nannoplankton assemblages in three distinct types of material—(i) Cretaceous chalk, (ii) Miocene marls, and (iii) late Holocene calcareous ooze. Two independent experimental runs within a semi‐enclosed system setting were realized to observe assemblage alterations. One experiment was realized with the presence of bacteria and, in contrast, the second one inhibited their potential effect on the studied system. The pH was gradually decreased within the range of 8.3–6.4 using a reaction of CO 2 with H 2 O forming weak carbonic acid (H 2 CO 3 ), thereby affecting []. Further, a subsequent overgrowth study was carried out during spontaneous degassing accompanied by a gradual pH rise. The experiment revealed that the process and intensity of coccolith corrosion and subsequent overgrowth build‐ups are influenced by a plethora of different factors such as (i) pH and associated seawater chemistry, (ii) mineral composition of the sediment, (iii) the presence of coccoliths within a protective substrate (faecal pellets, pores, pits), and (iv) the presence/absence of bacteria. Nannoplankton assemblages with corroded coccoliths or with coccoliths with overgrowth build‐ups showed that the observed relative abundances of taxa experienced alteration from the original compositions. Additionally, extreme pH oscillations may result in enhanced morphological changes that make coccoliths unidentifiable structures, and might even evoke the absence of coccoliths in the fossil record. |
author2 |
Univerzita Karlova v Praze Grantová Agentura České Republiky |
format |
Article in Journal/Newspaper |
author |
Holcová, Katarína Scheiner, Filip |
spellingShingle |
Holcová, Katarína Scheiner, Filip An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process |
author_facet |
Holcová, Katarína Scheiner, Filip |
author_sort |
Holcová, Katarína |
title |
An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process |
title_short |
An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process |
title_full |
An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process |
title_fullStr |
An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process |
title_full_unstemmed |
An experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: A rapid and complex process |
title_sort |
experimental study on post‐mortem dissolution and overgrowth processes affecting coccolith assemblages: a rapid and complex process |
publisher |
Wiley |
publishDate |
2022 |
url |
http://dx.doi.org/10.1111/gbi.12528 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12528 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/gbi.12528 |
genre |
Carbonic acid |
genre_facet |
Carbonic acid |
op_source |
Geobiology volume 21, issue 2, page 193-209 ISSN 1472-4677 1472-4669 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/gbi.12528 |
container_title |
Geobiology |
container_volume |
21 |
container_issue |
2 |
container_start_page |
193 |
op_container_end_page |
209 |
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1802643263210913792 |