Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature
Magnesium (Mg) isotopes in carbonate minerals are a useful proxy for paleoclimate studies, but interpretations are often limited by an inadequate understanding of the various factors controlling Mg isotopic fractionation during carbonate formation. Previous work has studied a number of parameters in...
| Autores: | , , , , , |
|---|---|
| Tipo de documento: | artigo |
| Estado: | Versión aceptada para publicación |
| Data de publicação: | 2020 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositório: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/215761 |
| Acesso em linha: | http://hdl.handle.net/10261/215761 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Carbonate Crystal morphology Magnesium isotopes Equilibrium isotope fractionation Chemo-stat |
| id |
ES_bc64a1c2acdde0c48d4e0dddabdf24c1 |
|---|---|
| oai_identifier_str |
oai:digital.csic.es:10261/215761 |
| network_acronym_str |
ES |
| network_name_str |
España |
| repository_id_str |
|
| dc.title.none.fl_str_mv |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature |
| title |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature |
| spellingShingle |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature Cheng, Xin-Yang Carbonate Crystal morphology Magnesium isotopes Equilibrium isotope fractionation Chemo-stat |
| title_short |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature |
| title_full |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature |
| title_fullStr |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature |
| title_full_unstemmed |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature |
| title_sort |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperature |
| dc.creator.none.fl_str_mv |
Cheng, Xin-Yang Teng, Fang-Zhen Sánchez, William R. Romanek, Christopher S. Sánchez Navas, Antonio Sánchez-Román, Mónica |
| author |
Cheng, Xin-Yang |
| author_facet |
Cheng, Xin-Yang Teng, Fang-Zhen Sánchez, William R. Romanek, Christopher S. Sánchez Navas, Antonio Sánchez-Román, Mónica |
| author_role |
author |
| author2 |
Teng, Fang-Zhen Sánchez, William R. Romanek, Christopher S. Sánchez Navas, Antonio Sánchez-Román, Mónica |
| author2_role |
author author author author author |
| dc.contributor.none.fl_str_mv |
European Commission Ministerio de Economía y Competitividad (España) National Science Foundation (US) NASA Astrobiology Institute Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72] |
| dc.subject.none.fl_str_mv |
Carbonate Crystal morphology Magnesium isotopes Equilibrium isotope fractionation Chemo-stat |
| topic |
Carbonate Crystal morphology Magnesium isotopes Equilibrium isotope fractionation Chemo-stat |
| description |
Magnesium (Mg) isotopes in carbonate minerals are a useful proxy for paleoclimate studies, but interpretations are often limited by an inadequate understanding of the various factors controlling Mg isotopic fractionation during carbonate formation. Previous work has studied a number of parameters including aqueous chemistry, mineralogy, temperature, and precipitation rate. However, little is known about the impact of solid/solution ratio, calcite growth mechanism, and crystal morphology on isotope fractionation. In this work, two groups of seeded chemo-stat calcite precipitation experiments were conducted at 25 °C to explore the potential impact of crystal growth and morphology on the fractionation of Mg isotopes. Group-1 experiments (G1) contained nine individual runs that were performed under identical physicochemical conditions, except for solid/solution ratio and the length of an experiment. The isotope fractionation between precipitated calcite and aqueous solution is limited, with ΔMg ranging from −2.58 to −2.40‰ and an average of −2.49 ± 0.12‰ (2SD, n = 9). The Group-2 experiments (G2) contained 3 paired runs with solution Mg/Ca molar ratios of 0.5, 2.0, and 5.0, and yielded ΔMg values that ranged from −2.69 to −2.36‰ with an average of −2.62 ± 0.25‰ (2SD, n = 6). The average ΔMg value for both sets of experiments is −2.54 ± 0.22‰ (2SD, n = 15), and it is independent of precipitation rate, solution Mg/Ca molar ratio, solid/solution ratio, amount of overgrowth, and mol% Mg content in overgrowth. The form and texture of the calcite overgrowths in our experiments range from {104} rhombohedra with smooth crystal faces containing few macrosteps to {104} rhombohedra containing extensive evidence for 2-D nucleation on crystal faces, to more steeply sided rhombohedra {0kl}. While significant changes in crystal morphology are related to solid/solution ratio and solution composition in the G1 and G2 experiments, respectively, there was no difference in Mg isotope systematics, suggesting that crystal morphology does not affect the Mg isotopic composition of calcite within the range of features investigated and 2-D nucleation may be less affected by calcite growth kinetics than a spiral growth mechanism. Integrating our results with previous published values, an equilibrium isotopic fractionation factor of −2.47 ± 0.09‰ (weighted average ± weighted 2SD, n = 70) between calcite and aqueous solutions is derived at room temperature. |
| publishDate |
2020 |
| dc.date.none.fl_str_mv |
2020 2020 2020 2020 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article http://purl.org/coar/resource_type/c_6501 Postprint info:eu-repo/semantics/acceptedVersion |
| format |
article |
| status_str |
acceptedVersion |
| dc.identifier.none.fl_str_mv |
http://hdl.handle.net/10261/215761 |
| url |
http://hdl.handle.net/10261/215761 |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.relation.none.fl_str_mv |
#PLACEHOLDER_PARENT_METADATA_VALUE# info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CGL2016-75679-P http://dx.doi.org/10.1016/j.gca.2020.04.033 Sí |
| dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess |
| eu_rights_str_mv |
openAccess |
| dc.publisher.none.fl_str_mv |
Elsevier BV |
| publisher.none.fl_str_mv |
Elsevier BV |
| dc.source.none.fl_str_mv |
reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC instname:Consejo Superior de Investigaciones Científicas (CSIC) |
| instname_str |
Consejo Superior de Investigaciones Científicas (CSIC) |
| reponame_str |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| collection |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| repository.name.fl_str_mv |
|
| repository.mail.fl_str_mv |
|
| _version_ |
1869418109878665216 |
| spelling |
Experimental constraints on magnesium isotope fractionation during abiogenic calcite precipitation at room temperatureCheng, Xin-YangTeng, Fang-ZhenSánchez, William R.Romanek, Christopher S.Sánchez Navas, AntonioSánchez-Román, MónicaCarbonateCrystal morphologyMagnesium isotopesEquilibrium isotope fractionationChemo-statMagnesium (Mg) isotopes in carbonate minerals are a useful proxy for paleoclimate studies, but interpretations are often limited by an inadequate understanding of the various factors controlling Mg isotopic fractionation during carbonate formation. Previous work has studied a number of parameters including aqueous chemistry, mineralogy, temperature, and precipitation rate. However, little is known about the impact of solid/solution ratio, calcite growth mechanism, and crystal morphology on isotope fractionation. In this work, two groups of seeded chemo-stat calcite precipitation experiments were conducted at 25 °C to explore the potential impact of crystal growth and morphology on the fractionation of Mg isotopes. Group-1 experiments (G1) contained nine individual runs that were performed under identical physicochemical conditions, except for solid/solution ratio and the length of an experiment. The isotope fractionation between precipitated calcite and aqueous solution is limited, with ΔMg ranging from −2.58 to −2.40‰ and an average of −2.49 ± 0.12‰ (2SD, n = 9). The Group-2 experiments (G2) contained 3 paired runs with solution Mg/Ca molar ratios of 0.5, 2.0, and 5.0, and yielded ΔMg values that ranged from −2.69 to −2.36‰ with an average of −2.62 ± 0.25‰ (2SD, n = 6). The average ΔMg value for both sets of experiments is −2.54 ± 0.22‰ (2SD, n = 15), and it is independent of precipitation rate, solution Mg/Ca molar ratio, solid/solution ratio, amount of overgrowth, and mol% Mg content in overgrowth. The form and texture of the calcite overgrowths in our experiments range from {104} rhombohedra with smooth crystal faces containing few macrosteps to {104} rhombohedra containing extensive evidence for 2-D nucleation on crystal faces, to more steeply sided rhombohedra {0kl}. While significant changes in crystal morphology are related to solid/solution ratio and solution composition in the G1 and G2 experiments, respectively, there was no difference in Mg isotope systematics, suggesting that crystal morphology does not affect the Mg isotopic composition of calcite within the range of features investigated and 2-D nucleation may be less affected by calcite growth kinetics than a spiral growth mechanism. Integrating our results with previous published values, an equilibrium isotopic fractionation factor of −2.47 ± 0.09‰ (weighted average ± weighted 2SD, n = 70) between calcite and aqueous solutions is derived at room temperature.We thank Sylvia Riechelmann and one anonymous reviewer for their insightful and critical comments, which significantly improved the manuscript. The careful and efficient editorial handing by AE Adrian Immenhauser is greatly appreciated. We would also like to thank Bing-Yu Lee for assistance on sample processing and column chemistry for Mg isotope analyses, Heng-Ci Tian, Yan Hu, and Mingzhu Liu for discussion and constructive comments, Jon Tonner for assistance on PHREEQC, and the Quantachrome’s Material Characterization Laboratory for providing surface area analyses of calcite seed material. This work was financially supported by National Science Foundation EAR-1747706, NASA Astrobiology Institute grant NNA13AA94A, the Summer Research Fellowship program through the Office of Undergraduate Research at Furman University, the Spanish Government FEDER projects CGL2016-75679-P and CGL2016-79458-P, and the Dutch Research Council (NWO) Origins Center project 190438131.Elsevier BVEuropean CommissionMinisterio de Economía y Competitividad (España)National Science Foundation (US)NASA Astrobiology InstituteConsejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]2020202020202020info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Postprintinfo:eu-repo/semantics/acceptedVersionhttp://hdl.handle.net/10261/215761reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglés#PLACEHOLDER_PARENT_METADATA_VALUE#info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CGL2016-75679-P http://dx.doi.org/10.1016/j.gca.2020.04.033Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/2157612026-05-22T06:33:51Z |
| score |
15,811543 |