PHYSICAL HISTORY OF THE VALLEY OF THE AMAZONS.

The article presents the author's insights on the physical history of the Valley of Amazons in Brazil. The author states that the valley is a cretaceous basin with two elevated land tracts such as Guiana plateau in the north and central plateau in the south. He also notes that it resembles the two continents of South and North America. He adds that three geological formations of clay deposits are found in the Amazon valley.