I have a book written in 1892 by a mineralogist who made several exploratory trips on that region, for government state. There is a passage in his book concerning the area you pointed out, this caught my attention:
"That mountains there are abundant deposits of gold, which were explored in 1660 years by several bands of adventurers, in a lake known as the "Dry Lake", on whose banks a priest who had fled from the chains (prision) of São Paulo (state), caught a lot of gold, which present a slave who had accompanied him, saying to slave: " - takes this gold!", and pointing to the lake, he had added, " - there, there you have your fortune" ".
Also, that place is near to a port city which was used as gold route in 1697-1702 years, to Portugal. This gold route was moved to another place because this pathway has been target of several pirate attacks.
Thanks for your attention. If you had any interest to make more surveys on that area, i can send to you coordinates.
Hello juniorsenior,
In all photos, dowsing revealed an attraction to alluvial gold in the areas of the green circles. River area is placer, the other locations shallow alluvial gold pockets. Green rectangle revealed a deposit of gold bars / jewellry associated with piracy.
Thanks for posting your photos.
Jon