2hats
Dust.
But if it is the real thing, then that would suggest the pilot went massively off course. In fact way back beyond where he started. South rather than north. Which would then beg the question why?
Even if this is the debris field and leads to the FDR/CVR and the remains of the cockpit (which they can then DNA test to establish who was flying it), and assuming the FDR wasn't purposefully disabled (the CVR could be 2 hours of wind noise with the odd instrumentation chime) there's going to be months (maybe years) of speculation until something can be reconstructed by accident investigators.