Well, Raul, perhaps you need a *Geological* dictionary

Cross-beds are, technically speaking, a natural occurence in sandstones and other sedimentary rocks where one set of beds dips at an angle and is cut by another set of beds. This can be extended to any surface where obvious angular truncation occurs which is thought NOT to be a an angular unconformity (an erosion surface caused by uplift, tilting, and peneplanation, followed by new sedimentation)

Crossbeds indicate the existence and the scale of former ripples or dunes. Water lain ripples are typically a few cm in height. Aeolian dunes are a few cm to tens of metres in height.

Dune/ripple crossbeds are often curved, sweeping smoothly into parallel strata at the toe of the dune, or they can have an abrupt angular base. See this example from Groetzinger et. al. (2005) of the outcrop at Burns Cliff.

At Cabo Frio, we see large scale (several metre) curved clinoforms (dipping beds) overlain by a truncation surface. Either we are seeing the angular uplift of the crater rim, later planed off, or we are seeing aeolian dunes.

Since the ange of dip crosses the crater wall at an oblique angle, it seems more likely that these are original sedimentary cross-beds from Aeolian dunes.

I strongly reccomend a good read through the discussions and the excellent pictures at unmannedspaceflight.com