Archaeologists have unearthed evidence that the oldest civilisation in the Americas dates back 400 years earlier than previously thought. New radiocarbon dating of 95 samples taken from pyramid mounds and houses suggest that by 3100 BCE there were complex societies and communal building of religious monuments across three valleys in Peru. This emerging civilisation was the first in the Americas to develop centralised decision-making, formalised religion, social hierarchies and a mixed economy based on agriculture and fishing.
     The newly uncovered sites in the Fortaleza and Pativilca valleys, along with the nearby previously reported sites in the Supe valley are seen as the earliest common roots of the Inca empire. Jonathan Haas, of the department of anthropology at the Field Museum in Chicago, who is the lead author of the research, said: "These sites dates push back the origins of civilization in the Americas to something more parallel to those of the other great early civilizations."
     Fieldwork carried out in the 1970s and 1980s at a nearby site, Aspero, at the mouth of the Supe river, demonstrated that the fishing community was occupied during the Late Archaic period, also known as the Cotton Pre-Ceramic period, between 3,000 and 1,800 BCE. Three years ago the existence of one of the world's biggest early cities further up the Supe valley at Caral was revealed. The settlement, believed to have had at least 3,000 inhabitants, included platform mounds thought to be pyramids, central plazas, temples and housing. The largest pyramid at Caral, known as the Primade Mayor, dating from 2627 BCE, measures 500ft by 450ft and rises to 60ft high with a flat top containing rooms, chambers, stairways and hearths for ceremonial activities.
     Work completed last year in the Fortaleza and Pativilca valleys to the north has revealed the existence of a network of 20 separate major residential centres, with monumental architecture across three valleys. The sites vary in size from 10 to 100 hectares (25 to 250 acres) and contain platform mounds, sunken circular plazas 20-40 metres in diameter, irrigation canals and expanses of housing. From this data, the archaeologists have concluded that there was large-scale communal construction and population concentration right across the Norte Chico region at the very beginning of the third millennium BCE.
     Dr José Oliver, a lecturer in Latin American archaeology at the Institute of Archaeology at University College London, said: "This confirms that by 3100 BCE monumental buildings were already under way, not just at an isolated site but across a whole region. Dr Colin McEwan, curator of the Latin American collection at the British Museum, said: "The use of carbon dating has allowed us to say the Andes is firmly on the stage as one of the great early areas that witnessed the rise of independent civilization alongside Mesopotamia, China, Egypt, the Indus and Mesoamerica."

Sources: BBC News (22 December 2004), Telegraph.co.uk (23 December 2004)