It basically boils down to geography: which of two Brazilian states you're from.
Belem Amazonians are from the northeast state of Para, that holds the mouth of the Amazon and has an Atlantic coast.
Brazilian Amazons are from the northern, inland state of Amazona.
According to a 2015 autosomal study at
https://en.wikipedia.org/wiki/Race_and_ ... _in_Brazil, the three groups of European (mainly Portuguese), African, and American Indian make up each population. The difference is described in percentages, with Belem Amazonians (Atlantic coastal state moving into the interior) 58% Euro, 27% African, 15% American Indian, and Brazilian Amazon (completely interior state further west on the continent) 51% Euro, 16% African, 32% American Indian.
We shy away from absolute percentages because no population is pure, but I think the ratios speak for themselves: The more interior the tribes, the less mixing with immigrant populations whether from Europe or Africa.
Hope this clarifies the two populations for you,
Jakay