Thank you Mark, both for the link and for keeping to your promise.
Thank you Indiana, i mean Jim

. Absolutely right; weapons do not know geographic boundaries ... pitty they know
price boundaries
Thank you David. If i well understand you, i don't think the point was originaly off centered; this must have happened when somebody decided that this object would make a good chisel

... it seems as its hammering caused a little crack in the socket which resulted in its bending.
About the provenance, i must confess that, at this stage, i have no more certainties than when i started querying on this piece, despite some respectfull opinnions posted by you Gents. However my inclination goes to both Mark's and this local guy's opinnion that it is a sort of lance or pike head. Following that reasoning, i tend to think this is not African or Afro influenced, but of (very old) European trace. Putting Africa out of question and, considering it has been picked somewhere in the interior, it would then be Portuguese or, in second place, Spanish rather than from further European countries.
However naturaly i can only agree that, till some stronger evidence shows up, the game's afoot.