On the technical details of the image and its line drawing below. In my dissertation, I recognized two distinct types of laminae produced by antidunes.
The first, which I call "type 1" lies in sharp erosional contact with the underlying sediment. In my box cores, these thin (<1 mm thick) laminae are defined by fine, magnetite-rich sand with coarser arkosic sand lying gradationally above the laminae. These laminae define the basal portion of a inversely-graded packet of sediment that are commonly lenticular, though can be somewhat tabular in appearance. These laminae typically dip in the downstream direction, though locally show a transition from downstream to upstream dips, giving a sigmoidal or s-shaped appearance to the laminae.
The second type of laminae, "type 2", are defined by alternating zones of magnetite-rich and arkosic sand. These laminae show variable thickness between 0.5 and 3 mm. The laminae generally dip in an upstream direction and are flat or concave up along their length. Type 2 laminae are truncated by type 1 laminae at their up-dip ends and merge into type 1 laminae in the down-dip direction.
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