التفاصيل البيبلوغرافية
| العنوان: |
Dissolution of nontronite in chloride brines and implications for the aqueous history of Mars |
| المؤلفون: |
Steiner, M. H., Hausrath, E. M., Madden, M. E. Elwood, Tschauner, O., Ehlmann, B. L., Olsen, A. A., Gainey, S. R., Smith, J. S. |
| المصدر: |
Geochimica et Cosmochimica Acta, 195, 259-276, (2016-12-15) |
| بيانات النشر: |
Elsevier |
| سنة النشر: |
2016 |
| المجموعة: |
Caltech Authors (California Institute of Technology) |
| مصطلحات موضوعية: |
Mars, Nontronite, Clay minerals, Dissolution, Brines, Habitability, Chlorides |
| الوصف: |
Increasing evidence suggests the presence of recent liquid water, including brines, on Mars. Brines have therefore likely impacted clay minerals such as the Fe-rich mineral nontronite found in martian ancient terrains. To interpret these interactions, we conducted batch experiments to measure the apparent dissolution rate constant of nontronite at 25.0 °C at activities of water (aH_2O) of 1.00 (0.01 M CaCl_2 or NaCl), 0.75 (saturated NaCl or 3.00 mol kg^(−1) CaCl_2), and 0.50 (5.00 mol kg^(−1) CaCl_2). Experiments at aH_2O = 1.00 (0.01 M CaCl_2) were also conducted at 4.0 °C, 25.0 °C, and 45.0 °C to measure an apparent activation energy for the dissolution of nontronite. Apparent dissolution rate constants at 25.0 °C in CaCl_2-containing solutions decrease with decreasing activity of water as follows: 1.18 × 10^(−12) ± 9 × 10^(−14) mol mineral m^(−2) s^(−1) (aH_2O = 1.00) > 2.36 × 10^(−13) ± 3.1 × 10^(−14) mol mineral m^(−2) s^(−1) (aH_2O = 0.75) > 2.05 × 10^(−14) ± 2.9 × 10^(−15) mol mineral m^(−2) s^(−1) (aH_2O = 0.50). Similar results were observed at 25.0 °C in NaCl-containing solutions: 1.89 × 10^(−12) ± 1 × 10^(−13) mol mineral m^(−2) s^(−1) (aH_2O = 1.00) > 1.98 × 10^(−13) ± 2.3 × 10^(−14) mol mineral m^(−2) s^(−1) (aH_2O = 0.75). This decrease in apparent dissolution rate constants with decreasing activity of water follows a relationship of the form: log k_(diss) = 3.70 ± 0.20 × aH_2O − 15.49, where k^(diss) is the apparent dissolution rate constant, and aH_2O is the activity of water. The slope of this relationship (3.70 ± 0.20) is within uncertainty of that of other minerals where the relationship between dissolution rates and activity of water has been tested, including forsteritic olivine (log R = 3.27 ± 0.91 × aH_2O − 11.00) (Olsen et al., 2015) and jarosite (log R = 3.85 ± 0.43 × aH_2O − 12.84) (Dixon et al., 2015), where R is the mineral dissolution rate. This result allows prediction of mineral dissolution as a ... |
| نوع الوثيقة: |
article in journal/newspaper |
| اللغة: |
unknown |
| العلاقة: |
https://doi.org/10.1016/j.gca.2016.08.035Test; oai:authors.library.caltech.edu:62dcd-hjf15; eprintid:71736; resolverid:CaltechAUTHORS:20161104-091802689 |
| DOI: |
10.1016/j.gca.2016.08.035 |
| الإتاحة: |
https://doi.org/10.1016/j.gca.2016.08.035Test |
| حقوق: |
info:eu-repo/semantics/openAccess ; Other |
| رقم الانضمام: |
edsbas.DFA9D3C2 |
| قاعدة البيانات: |
BASE |
