Figure 8. Portion of a
Mastcam color mosaic taken on sol 2991 at the northern edge of the Sands
of Forvie looking to the southeast into the sand sheet. Platy bedrock is
evident in the mid-ground on the left side of the mosaic. Letters at the
top of the figure denote direction. Image credit: NASA/JPL-Caltech/MSSS.
A subordinate direction is indicated by superimposed smaller ripples
located in the larger ripple troughs (Figure 8). ACuriosity -based measurement campaign was conducted on the
northern edge of the SoF sand deposit. Unfortunately, scoop samples were
not acquired for delivery to CheMin. A left wheel scuff excavated across
a transverse ripple crest and Mastcam color image data show that the
surface exhibits a relatively reddish-brown color, whereas the interior
contains darker sands intermixed with brighter grains (Figure 9). APXS
data were acquired on four targets at the SoF measurement site: Braewick
Beach, Airor, Ratharsair, and Traquir (Weitz et al., 2022). All four
targets were compositionally similar, with low S, Cl, and Zn, consistent
with low dust content expected on an active aeolian bedform. Grain sizes
measured from MAHLI image data showed that the ripple crests contain
slightly larger grains than the troughs, as is typical for the sand
deposits studied by Curiosity , with evidence that the coarser
grains correlate with high Ni content (Weitz et al., 2018, 2022).