This is a more detailed close-up view of the HiRISE image of Holden crater. It shows
layers revealed when Holden crater rim was breached, unleashing water that scoured
out parts of Holden crater. From the bottom up, these include the base of impac
megabreccia, contrasting smooth sedimentary layers, another darker, crudely layered
unit, and dark wind-blown material on the surface. These layers correspond to layers
in the illustrative drawing, above left. (NASA/JPL/University of Arizona) |