Make that "autochthonic".

According to the only stories we have about the Scandinavians in North America (they weren't really "Vikings" at that point), they traded with the natives, and fought with them. Sometimes the natives started the fights, and sometimes they won. The Scandinavians didn't get close enough to rape anybody that we know of, and weren't around long enough to steal anybody's land. Maybe they would have if they'd stayed around, and maybe they did inadvertently pass on diseases, but this is purely speculative.