As usual, the pictures are well ahead of the text. Oppy is now (Sol 281) safely arrived on the rocky slope at the base of the cliff. Traction looks good again. Some interesting pictures relevant to jms in SOL 280 Pancam - looks like the beginning of a nother giant mosaic.

This one is important:-

Link to full-res pic

Note three things:

1) These deeper layered rocks are also shot through with blueberries, but more crudely layered than the upper units.

2) There is a piece of finely-layered rock, fallen from above, at top centre of the frame. This allows a nice comparison of layering and, most importantly, density of blueberries.

3) I interpret the density of blueberries to be higher in this deeper unit than in the surface layer. There seem to be more of them, and even twinned ones in-situ.

Wait for confirmation of this, but it suggests that the rocks down here have a higher iron content, and that most of the iron has been converted from mafic minerals into haematite.