Academic Journal
Photooxidation of Evaporative Ferrous-Ferric Sulfate Brines under a Martian CO 2 Atmosphere
| العنوان: | Photooxidation of Evaporative Ferrous-Ferric Sulfate Brines under a Martian CO 2 Atmosphere |
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| المؤلفون: | Di-Sheng Zhou, Xiyu Wang, Yu-Yan Sara Zhao, Weiqiang Li, Junhu Wang, Dongdong Li, Zongcheng Ling, Yang Li, Xiongyao Li, Jianzhong Liu |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Biophysics, Biochemistry, Microbiology, Genetics, Evolutionary Biology, Ecology, Environmental Sciences not elsewhere classified, Astronomical and Space Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, ph ≤ 2, persistent cold environment, minor phase occurring, lower hydration states, g ., ferricopipiate, amorphous materials detected, also nanocrystalline sulfates, crystallization may indicate, sulfate brines evolve, ferric sulfate brines, nanocrystalline fe oxides, stronger oxidizing conditions, ferrihydrite, clear evolution pathway, iii , 2 , fe sulfate brines, sulfate brines, |
| الوصف: | Iron is an essential tracer of the evolution of aqueous environments, redox conditions, and habitability on the Martian surface. At present, there is still a lack of constraints on the initial Fe II /Fe T ratios of Martian brines and how evaporative Fe II –Fe III sulfate brines evolve under a CO 2 atmosphere and ultraviolet (UV) irradiation. In this study, we experimentally investigated the evaporation of Fe sulfate brines (initial Fe II /Fe T ratios from 1 to 0; pH ≤ 2.8) under CO 2 , UV/CO 2 , and UV/Earth conditions. Our results show that rapid dehydration of acidic Fe II –Fe III sulfate brines produces Fe II - and Fe III -sulfates separately. Rozenite is the primary Fe II -sulfate phase in most cases and is usually associated with szomolnokite, which forms via rozenite dehydration. Fe II -sulfate evaporites show a clear evolution pathway of dehydration from 7w or 4w to lower hydration states. Rhomboclase–ferricopiapite mixtures are primary Fe III phases, and kornelite is a minor phase occurring only when RH > 30%. Oxidization of Fe II -sulfate brines produces ferrihydrite under UV/CO 2 conditions and a mixture of schwertmannite, ferrihydrite, hydronium jarosite, and hematite under UV/Earth conditions. Acidic and concentrated Fe II –Fe III sulfate brines can still be oxidized on present Mars. Evaporative and oxidative products show better crystallinity and variety under stronger oxidizing conditions. Fe III phases may be important contributors to amorphous materials detected on Mars, not only in the form of nanocrystalline Fe oxides (e.g., ferrihydrite and hematite) but also nanocrystalline sulfates (e.g., ferricopipiate) and colloids by Fe III hydrolysis. Fe III phases are good reservoirs of H 2 O in general, and their lack of further crystallization may indicate a persistent cold environment on Mars. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | unknown |
| Relation: | https://figshare.com/articles/journal_contribution/Photooxidation_of_Evaporative_Ferrous-Ferric_Sulfate_Brines_under_a_Martian_CO_sub_2_sub_Atmosphere/24872138 |
| DOI: | 10.1021/acsearthspacechem.3c00164.s001 |
| الاتاحة: | https://doi.org/10.1021/acsearthspacechem.3c00164.s001 https://figshare.com/articles/journal_contribution/Photooxidation_of_Evaporative_Ferrous-Ferric_Sulfate_Brines_under_a_Martian_CO_sub_2_sub_Atmosphere/24872138 |
| Rights: | CC BY-NC 4.0 |
| رقم الانضمام: | edsbas.ACC4A2C4 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1021/acsearthspacechem.3c00164.s001 |
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