Just published in the most recent issue of Geology:

Grotzinger, et al., 2006, Sedimentary textures formed by aqueous processes, Erebus crater, Meridiani Planum, Mars: Geology, v. 34, p. 1085-1088.

Trough cross-lamination/"festoons" and shrinkage cracks...and everyone down to the person that tightened the lug nuts on Opportunity is a co-author