Organic adsorption onto iron sulfide and hydroxide minerals: Implications for Ceres sample return analysis.
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
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
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.