Soil grain analyses at Meridiani Planum, Mars

Journal of Geophysical Research E: Planets
By: , and 



Grain‐size analyses of the soils at Meridiani Planum have been used to identify rock sources for the grains and provide information about depositional processes under past and current conditions. Basaltic sand, dust, millimeter‐size hematite‐rich spherules interpreted as concretions, spherule fragments, coated partially buried spherules, basalt fragments, sedimentary outcrop fragments, and centimeter‐size cobbles are concentrated on the upper surfaces of the soils as a lag deposit, while finer basaltic sands and dust dominate the underlying soils. There is a bimodal distribution of soil grain sizes with one population representing grains <125 μm and the other falling between 1–4.5 mm. Soils within craters like Eagle and Endurance show a much greater diversity of grain morphologies compared to the plains. The spherules found in the plains soils are approximately 1–2 mm smaller in size than those seen embedded in the outcrop rocks of Eagle and Endurance craters. The average major axis for all unfractured spherules measured in the soils and outcrop rocks is 2.87 ± 1.18 mm, with a trend toward decreasing spherule sizes in both the soils and outcrop rocks as the rover drove southward. Wind ripples seen across the plains of Meridiani are dominated by similar size (1.3–1.7 mm) hematite‐rich grains, and they match in size the larger grains on plains ripples at Gusev Crater. Larger clasts and centimeter‐size cobbles that are scattered on the soils have several spectral and compositional types, reflecting multiple origins. The cobbles tend to concentrate within ripple troughs along the plains and in association with outcrop exposures.

Publication type Article
Publication Subtype Journal Article
Title Soil grain analyses at Meridiani Planum, Mars
Series title Journal of Geophysical Research E: Planets
DOI 10.1029/2005JE002541
Volume 111
Issue E12
Year Published 2006
Language English
Publisher American Geophysical Union
Publisher location Washington, D.C.
Contributing office(s) Astrogeology Science Center
Description 26 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Geophysical Research E: Planets
Other Geospatial Mars; Meridiani Planum
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