The document discusses the presence of pyrophyllite in soil samples from the western Amazon region near the Brazil-Peru border. It analyzes the clay fraction of two Fluvent soils near the Javari River, one Aquent soil near an abandoned meander channel, and two Udult soils on an adjacent terrace. Pyrophyllite was found in the fine silt fractions of all the soils except one Fluvent, and in the coarse clay of the two Ultisols. The pyrophyllite appears to have been inherited from the parent sediments, as it was present across soil types, suggesting it is more resistant to weathering than chlorite.