Mineralogy of a Mudstone at Yellowknife Bay, Gale Crater, Mars

• Published in: Science
• Main Authors: Vaniman, D. T., Bish, D. L., Ming, D. W., Bristow, T. F., Morris, R. V., Blake, D. F., Chipera, S. J., Morrison, S. M., Treiman, A. H., Rampe, E. B., Rice, M., Achilles, C. N., Grotzinger, J., McLennan, S. M., Williams, J., Bell, J., III, Newsom, H., Downs, R. T., Maurice, S., Sarrazin, P., Yen, A. S., Morookian, J. M., Farmer, J. D., Stack, K., Milliken, R. E., Ehlmann, B., Sumner, D. Y., Berger, G., Crisp, J. A., Hurowitz, J. A., Anderson, R., Des Marais, D., Stolper, E. M., Edgett, K. S., Gupta, S., Spanovich, N.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science 2014
• Subjects: Yellowknife; Yellowknife Bay
• Online Access: https://authors.library.caltech.edu/42649/; https://authors.library.caltech.edu/42649/1/Vaniman%201243480%20mineralogy%20revised%20Nov%20final.pdf; https://authors.library.caltech.edu/42649/7/Vaniman1243480s%20Supplemental%20material%20revised%20Nov%20final.pdf; https://resolver.caltech.edu/CaltechAUTHORS:20131122-100923777

Sedimentary rocks at Yellowknife Bay (Gale Crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, Ca-sulfates, Fe oxide/hydroxides, Fe-sulfides, amorphous material, and trioctahedral smectites. The John Klein smectite has basal spacing of ~10 Å indicating little interlayer hydration. The Cumberland smectite has basal spacing at ~13.2 Å as well as ~10 Å. The ~13.2 Å spacing suggests a partially chloritized interlayer or interlayer Mg or Ca facilitating H_2O retention. Basaltic minerals in the mudstone are similar to those in nearby eolian deposits. However, the mudstone has far less Fe-forsterite, possibly lost with formation of smectite plus magnetite. Late Noachian/Early Hesperian or younger age indicates that clay mineral formation on Mars extended beyond Noachian time.