2026
Mars mineral weathering experiments in a continuous-flow reactor
J. M. Weber, E. M. Martinez, R. Y. Sheppard, L. E. Rodriguez, A. Celestian, B. L. Teece, L.
M. Barge. In press, Geofluids.
2026
Non-destructive description of Bennu samples towards comparative studies with Ryugu samples
R. Fukai, M. Nishimura, K. Yumoto, Y. Cho, Y. Shimizu, M. Matsuoka, E. Tatsumi, S. Furukawa,
T. Yada, K. Hatakeda, K. Yogata, Y. Enokido, R. Tahara, A. Miyazaki, S. Kawasaki, S. Sugita, S.
Mori, S. Nakahara, Y. Aikyo, H. Miyamoto, C. Pilorget, D. Loizeau, L. Nardelli, R. Sheppard, C. Lantz, L. Riu, J.-P. Bibring, R. Brunetto, T. Okada, M. Abe, T. Usui. In press, Meteoritics and Planetary Science.
2026
The effect of clay minerals on Li in martian groundwater simulant
R. Y. Sheppard, J. M. Weber, L. E. Rodriguez, C. Trejo, E. M. Hausrath, L. M. Barge. Icarus, 443, 116769. doi:10.1016/j.icarus.2025.116769
Compositional diversity in pristine Bennu samples revealed by the IR hyperspectral microscope MicrOmega at JAXA Curation Center and comparison with Ryugu samples
2025
C. Pilorget, T. Okada, J.-P. Bibring, D. Loizeau, K. Hatakeda, L. Nardelli, L. Riu, R. Y. Sheppard, T. Jiang, M. Mahlke, R. Brunetto, R. Fukai, M. Abe, A. Aléon-Toppani, D. Baklouti, Y. Enokido, V. Hamm, S. Kawasaki, C. Lantz, A. Miyazaki, A. Moussi-Soffys, M. Nishimura, F. Poulet, R. Tahara, T. Usui, T. Yada, K. Yogata. Nature Communications, 16:9532, doi:10.1038/s41467-025-65438-z.
Mg sulfate can spectrally obscure siderite: Implications for martian surface carbonates
2025
R. Y. Sheppard, D. Loizeau, A. A. Fraeman, E. B. Rampe, C. Pilorget, J.-P. Bibring. Frontiers in Astronomy and Space Sciences special issue, “Remote Sensing and Modelling of Planetary and Moon Surfaces,” 12:1549242. doi:10.3389/fspas.2025.1549242.
Diagenetic features reveal the influence of the Greenheugh Pediment on the alteration history of Gale crater, Mars.
2025
J. Ando, R. Y. Sheppard, A. B. Bryk, V. Sun, C. H. Seeger, A. A. Fraeman, A. M. Eng, L. Kah, A. N. Rudolph. Journal of Geophysical Research: Planets, 130, e2024JE008891. doi:10.1029/2024JE008891.
2025
Dark-toned halite-enriched veins above the Marker Band record a drying environment in Gale Crater
A. R. Trussell, J. F. Bell III, W. H. Farrand, L. C. Kah, E. B. Hughes, C. D. O’Connell-Cooper,
L. M. Thompson, R. Y. Sheppard, H. Manelski, G. Paar, B. S. Douglass, A. M. Eng, J. R. Johnson.
Journal of Geophysical Research: Planets, 130, e2025JE009244.
2025
Chapter “Lithologic and textural context of clays inferred from
remote sensing” within the book Clay on Mars
R. Y. Sheppard, J. Cuadros. Editor: Javier Cuadros. Elsevier, Developments in Clay Science, Volume 12.
Organic adsorption onto iron sulfide and hydroxide minerals: Implications for Ceres sample return analysis
2025
E. M. Martinez, E. Flores, D. Valadez, J. M. Weber, D. VanderVelde, R. Y. Sheppard, R. P. Hodyss, J. Castillo-Rogez, M. Melwani Daswani, B. Henderson, L. M. Barge. doi:10.1021/acsearthspacechem.4c00372
Pediment formation and subsequent erosion in Gale crater: Clues to climate history of Mars
2025
2024
Simulated Fe/Mg-silicate chimneys as analogs to saponite-rich hydrothermal systems on early Earth and Mars
An orbital comparison of a late mantling unit on Aeolis Mons with other erosion-resistant strata explored by MSL in Gale crater, Mars
2024
Chemical gardens as analogs for prebiotic chemistry on ocean worlds
2024
2024
The geological context and significance of the clay-sulfate transition region in Mount Sharp, Gale crater, Mars: An integrated assessment based on orbiter and rover data
A Mastcam multispectral investigation of rock variability in Gale crater, Mars: Implications for alteration in the clay-sulfate transition of Mount Sharp
2024
Nitrate reactivity in iron (oxy)hydroxide systems: Effect of pH, iron redox state, and phosphate
2023
Compositional variations in sedimentary deposits in Gale crater as observed by ChemCam passive and active spectra
2023
H. T. Manelski, R. Y. Sheppard, A. A. Fraeman, R. C. Wiens, J. R. Johnson, E. B. Rampe, J. Frydenvang, N. L. Lanza, O. Gasnault. Journal of Geophysical Research: Planets. 128, 3.
Presence of clay minerals can obscure spectral evidence of Mg sulfates: Implications for orbital observations of Mars.
2022
R. Y. Sheppard, R. E. Milliken, K. M. Robertson. Icarus. 383, 115083.
Preservation biases are pervasive in Holocene paleofire records
2022
R. S. Vachula, R. Y. Sheppard, & A. H. Cheung. Palaeogeography, Palaeoclimatology, Palaeoecology. 602, 111165.
Chirality in organic and mineral systems: A review of reactivity and alteration processes relevant to prebiotic chemistry and life detection missions
2022
C. Lee, J. M. Weber, L. E. Rodriguez, R. Y. Sheppard, L. M. Barge, E. L. Berger, A. S. Burton. Symmetry special issue, “Chirality, Prebiotic Chemistry, and the Origins of Life.”
2022
Database on carbon reduction: Implications for future research
M. Prakash, J. M. Weber, L. E. Rodriguez, R. Y. Sheppard, L. M. Barge. International Journal of Astrobiology, 1-18.
Merging perspectives on secondary minerals on Mars: A review of ancient water-rock interactions in Gale crater inferred from orbital and in situ observations
2021
R. Y. Sheppard, M. T. Thorpe, A. A. Fraeman, V. K. Fox, R. E. Milliken. Minerals special issue, “Expanding Views of Clays, Oxides, and Evaporites on Aquaplanets in the Solar System.” 11(986).
2021
Iron mineralogy and sediment color in a 100 m drill core from Lake Towuti, Indonesia reflect catchment and diagenetic conditions
R. Y. Sheppard, R. E. Milliken, J. M. Russell, M. D. Dyar, E. Sklute, H. Vogel, M. Melles, S. Bijaksana, A. K. M. Hasberg, M. A. Morlock. Geochemistry, Geophysics, Geosystems. 22, e2020GC009582.
2020
Updated Perspectives and Hypotheses on the Mineralogy of Lower Mt. Sharp, Mars, as seen from Orbit
R. Y. Sheppard, R. E. Milliken, Y. Itoh, M. Parente. Journal of Geophysical Research: Planets. 126.
2020
The Late Quaternary tectonic, biogeochemical, and environmental evolution of ferruginous Lake Towuti, Indonesia
J. Russell, H. Vogel, S. Bijaksana, M. Melles, A. Deino, A. Hafidz, A. Hasberg, M. Morlock, T. von Rintelen, R. Y. Sheppard, B. Stelbrink, J. Stevenson. Palaeogeography, Palaeoclimatology, Palaeoecology. 556, p. 109905.
2019
Characterization of iron in Lake Towuti sediment
R. Y. Sheppard, R. E. Milliken, J. M. Russell, M. D. Dyar, E. Sklute, H. Vogel, M. Melles, S. Bijaksana, A. K. M. Hasberg, M. A. Morlock. Chemical Geology. 512, pp. 11-30.
2017
Porosity and salt content determine if subduction can occur in Europa’s ice shell
B. C. Johnson, R. Y. Sheppard, A. C. Pascuzzo, E. A. Fisher, S. E. Wiggins. (2017) Journal of Geophysical Research: Planets. 122.
2015
Organic thermal maturity as a proxy for frictional fault heating: experimental constraints on methylphenanthrene kinetics at earthquake timescales
R. E. Sheppard, P. J. Polissar, H. M. Savage. (2015) Geochimica et Cosmochimica Acta. 151, pp. 103-116.
2014
Biomarkers heat up during earthquakes: New evidence of seismic slip in the rock record
H. M. Savage, P. J. Polissar, R. Sheppard, C. D. Rowe, E. E. Brodsky. (2014) Geology. 42(2), pp. 99-102.