Centimeter to decimeter hollow concretions and voids in Gale Crater sediments, Mars

Journal Article · Tue Feb 21 00:00:00 EST 2017 · Icarus

DOI:https://doi.org/10.1016/j.icarus.2017.02.003· OSTI ID:1394987

Wiens, Roger C. ^[1]; Rubin, David M. ^[2]; Goetz, Walter ^[3]; Fairén, Alberto G. ^[4]; Schwenzer, Susanne P. ^[5]; Johnson, Jeffrey R. ^[6]; Milliken, Ralph ^[7]; Clark, Ben ^[8]; Mangold, Nicolas ^[9]; Stack, Kathryn M. ^[10]; Oehler, Dorothy ^[11]; Rowland, Scott ^[12]; Chan, Marjorie ^[13]; Vaniman, David ^[14]; Maurice, Sylvestre ^[15]; Gasnault, Olivier ^[15]; Rapin, William ^[15]; Schroeder, Susanne ^[16]; Clegg, Sam ^[1]; Forni, Olivier ^[15] ; Blaney, Diana ^[10]; Cousin, Agnes ^[15]; Payré, Valerie ^[17]; Fabre, Cecile ^[17]; Nachon, Marion ^[18]; Le Mouelic, Stephane ^[9]; Sautter, Violaine ^[19]; Johnstone, Stephen ^[1]; Calef, Fred ^[10]; Vasavada, Ashwin R. ^[10]; Grotzinger, John P. ^[20]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Univ.of California, Santa Cruz, CA (United States). Dept. of Earth and Planetary Sciences
3. Max Planck Inst. for Solar System Research, Gottingen (Germany)
4. Center for Astrobiology, Madrid (Spain). Dept. of Planetology and Habitability; Cornell Univ., Ithaca, NY (United States). Dept. of Astronomy
5. Open Univ., Milton Keynes (United Kingdom). Dept. of Environment Earth and Ecosystems
6. Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Lab.
7. Brown Univ., Providence, RI (United States)
8. Space Science Inst., Boulder, CO (United States)
9. Univ. of Nantes (France). Lab. of Planetology and Geodynamics
10. California Inst. of Technology (CalTech), Pasadena, CA (United States). Jet Propulsion Lab.
11. NASA Johnson Space Center, Houston, TX (United States). IZ Technology
12. Univ. of Hawaii, Manoa, HI (United States)
13. Univ. of Utah, Salt Lake City, UT (United States)
14. Planetary Science Inst., Tucson, AZ (United States)
15. Univ. of Toulouse (France); French National Center for Scientific Research (CNRS), Toulouse (France). Inst. of Astrophysics and Planetary Research
16. German Aerospace Center (DLR), Berlin (Germany). Inst. of Optical Sensor Systems
17. Univ. of Lorraine, Nancy (France). GeoRessources
18. Univ. of California, Davis, CA (United States)
19. Institute of Mineralogy, Physics of Materials and Cosmo-Chemistry (IMPMC), Paris (France)
20. California Inst. of Technology (CalTech), Pasadena, CA (United States)

Voids and hollow spheroids between ~1 and 23 cm in diameter occur at several locations along the traverse of the Curiosity rover in Gale crater, Mars. These hollow spherical features are significantly different from anything observed in previous landed missions. The voids appear in dark-toned, rough-textured outcrops, most notably at Point Lake (sols 302–305) and Twin Cairns Island (sol 343). Point Lake displays both voids and cemented spheroids in close proximity; other locations show one or the other form. The spheroids have 1–4 mm thick walls and appear relatively dark-toned in all cases, some with a reddish hue. Only one hollow spheroid (Winnipesaukee, sol 653) was analyzed for composition, appearing mafic (Fe-rich), in contrast to the relatively felsic host rock. The interior surface of the spheroid appears to have a similar composition to the exterior with the possible exceptions of being more hydrated and slightly depleted in Fe and K. The origins of the spheroids as Martian tektites or volcanic bombs appear unlikely due to their hollow and relatively fragile nature and the absence of in-place clearly igneous rocks. A more likely explanation to both the voids and the hollow spheroids is reaction of reduced iron with oxidizing groundwater followed by some re-precipitation as cemented rind concretions at a chemical reaction front. Though some terrestrial concretion analogs are produced from a precursor siderite or pyrite, diagenetic minerals could also be direct precipitates for other terrestrial concretions. The Gale sediments differ from terrestrial sandstones in their high initial iron content, perhaps facilitating a higher occurrence of such diagenetic reactions.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: National Aeronautics and Space Administration (NASA)
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1394987
• Report Number(s): LA-UR-17-26881
• Journal Information: Icarus, Vol. 289, Issue C; ISSN 0019-1035
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
Concretions
Voids
Spherules
Nodules
Gale crater
Mars
Mars science laboratory