Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments

<p dir="ltr">The mineral Dolomite CaMg(CO<sub>3</sub>)<sub>2</sub> is a common constituent of sedimentary rocks. Despite centuries of research, the mechanism of its formation remains elusive and debated. Recent studies have shown the presence of silica in solu...

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محفوظ في:
التفاصيل البيبلوغرافية
المؤلف الرئيسي: Zulfa Ali Al Disi (13790381) (author)
مؤلفون آخرون: Tomaso R.R. Bontognali (17876750) (author), Fadhil Sadooni (17876747) (author), Hamad Al Saad Al-Kuwari (17886749) (author)
منشور في: 2024
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author Zulfa Ali Al Disi (13790381)
author2 Tomaso R.R. Bontognali (17876750)
Fadhil Sadooni (17876747)
Hamad Al Saad Al-Kuwari (17886749)
author2_role author
author
author
author_facet Zulfa Ali Al Disi (13790381)
Tomaso R.R. Bontognali (17876750)
Fadhil Sadooni (17876747)
Hamad Al Saad Al-Kuwari (17886749)
author_role author
dc.creator.none.fl_str_mv Zulfa Ali Al Disi (13790381)
Tomaso R.R. Bontognali (17876750)
Fadhil Sadooni (17876747)
Hamad Al Saad Al-Kuwari (17886749)
dc.date.none.fl_str_mv 2024-07-14T15:00:00Z
dc.identifier.none.fl_str_mv 10.1016/j.scitotenv.2024.174714
dc.relation.none.fl_str_mv https://figshare.com/articles/journal_contribution/Evaluating_the_role_of_dissolved_silica_for_dolomite_formation_in_evaporitic_environments_Insights_from_prolonged_laboratory_experiments/29900372
dc.rights.none.fl_str_mv CC BY 4.0
info:eu-repo/semantics/openAccess
dc.subject.none.fl_str_mv Earth sciences
Geochemistry
Geology
Dolomite
Dissolved silica
EPS
Cation ordering
dc.title.none.fl_str_mv Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
dc.type.none.fl_str_mv Text
Journal contribution
info:eu-repo/semantics/publishedVersion
text
contribution to journal
description <p dir="ltr">The mineral Dolomite CaMg(CO<sub>3</sub>)<sub>2</sub> is a common constituent of sedimentary rocks. Despite centuries of research, the mechanism of its formation remains elusive and debated. Recent studies have shown the presence of silica in solution promote the incorporation of Mg into the carbonate mineral, forming crystal phases that may be precursors to dolomite. The goal of this study was to evaluate with laboratory experiments whether dissolved silica may play a role for dolomite formation in sabkha (i.e., salt flats) environments. Several models for dolomite formation are based on the studies of sabkhas, which are often cited as modern analogue for ancient dolomite-rich sedimentary sequences. We performed long-incubation time (i.e., up to 600 days) laboratory precipitation experiments at 30 °C with solution mimicking the sabkha pore waters (characterized by a salinity of 23 % and Mg: Ca ratio of 15) to which we added different concentrations of Si. Our results revealed a positive correlation (<i>p</i>-value <0.001) between Si concentration in solution and the mol% Mg of the carbonate minerals forming in the experiment. With 2 mM of Si, the bulk precipitate was comprised of 90 % stoichiometric dolomite with possible signs or ordering. Moreover, the rhombohedral morphology of the crystals is analogue to that of natural dolomite previously described from sabkha sediments. Our results suggest that dissolved Si may play an important role for dolomite formation in evaporitic environments.</p><h2>Other Information</h2><p dir="ltr">Published in: Science of The Total Environment<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1016/j.scitotenv.2024.174714" target="_blank">https://dx.doi.org/10.1016/j.scitotenv.2024.174714</a></p>
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identifier_str_mv 10.1016/j.scitotenv.2024.174714
network_acronym_str Manara2
network_name_str Manara2
oai_identifier_str oai:figshare.com:article/29900372
publishDate 2024
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spelling Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experimentsZulfa Ali Al Disi (13790381)Tomaso R.R. Bontognali (17876750)Fadhil Sadooni (17876747)Hamad Al Saad Al-Kuwari (17886749)Earth sciencesGeochemistryGeologyDolomiteDissolved silicaEPSCation ordering<p dir="ltr">The mineral Dolomite CaMg(CO<sub>3</sub>)<sub>2</sub> is a common constituent of sedimentary rocks. Despite centuries of research, the mechanism of its formation remains elusive and debated. Recent studies have shown the presence of silica in solution promote the incorporation of Mg into the carbonate mineral, forming crystal phases that may be precursors to dolomite. The goal of this study was to evaluate with laboratory experiments whether dissolved silica may play a role for dolomite formation in sabkha (i.e., salt flats) environments. Several models for dolomite formation are based on the studies of sabkhas, which are often cited as modern analogue for ancient dolomite-rich sedimentary sequences. We performed long-incubation time (i.e., up to 600 days) laboratory precipitation experiments at 30 °C with solution mimicking the sabkha pore waters (characterized by a salinity of 23 % and Mg: Ca ratio of 15) to which we added different concentrations of Si. Our results revealed a positive correlation (<i>p</i>-value <0.001) between Si concentration in solution and the mol% Mg of the carbonate minerals forming in the experiment. With 2 mM of Si, the bulk precipitate was comprised of 90 % stoichiometric dolomite with possible signs or ordering. Moreover, the rhombohedral morphology of the crystals is analogue to that of natural dolomite previously described from sabkha sediments. Our results suggest that dissolved Si may play an important role for dolomite formation in evaporitic environments.</p><h2>Other Information</h2><p dir="ltr">Published in: Science of The Total Environment<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1016/j.scitotenv.2024.174714" target="_blank">https://dx.doi.org/10.1016/j.scitotenv.2024.174714</a></p>2024-07-14T15:00:00ZTextJournal contributioninfo:eu-repo/semantics/publishedVersiontextcontribution to journal10.1016/j.scitotenv.2024.174714https://figshare.com/articles/journal_contribution/Evaluating_the_role_of_dissolved_silica_for_dolomite_formation_in_evaporitic_environments_Insights_from_prolonged_laboratory_experiments/29900372CC BY 4.0info:eu-repo/semantics/openAccessoai:figshare.com:article/299003722024-07-14T15:00:00Z
spellingShingle Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
Zulfa Ali Al Disi (13790381)
Earth sciences
Geochemistry
Geology
Dolomite
Dissolved silica
EPS
Cation ordering
status_str publishedVersion
title Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
title_full Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
title_fullStr Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
title_full_unstemmed Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
title_short Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
title_sort Evaluating the role of dissolved silica for dolomite formation in evaporitic environments: Insights from prolonged laboratory experiments
topic Earth sciences
Geochemistry
Geology
Dolomite
Dissolved silica
EPS
Cation ordering