1491: New Revelations of the Americas Before Columbus

by Charles C. Mann

One of the biggest patches of terra preta is on the high bluffs at the mouth of the Tapajós, near Santarém. First mapped in the 1960s by the late Wim Sombroek, director of the International Soil Reference and Information Center in Wageningen, the Netherlands, the terra preta zone is three miles long and half a mile wide, suggesting widespread human habitation—exactly what Orellana saw. The plateau has never been carefully excavated, but observations by geographers Woods and Joseph McCann of the New School in New York City indicate that it is thick with ceramics. If the agriculture practiced in the lower Tapajós were as intensive as in the most complex cultures in precontact North America, Woods told me, “you’d be talking something capable of supporting about 200,000 to 400,000 people”—making it at the time one of the most densely populated places in the world.