4000 years of human impact and vegetation change in the central Peruvian Andes — with events parallelling the Maya record?

A lake-sediment sequence from Marcacocha in the central Peruvian Andes provides a well-dated and continuous vegetation record from an area rich in Inca and pre-Inca remains over the last 4000 years. Climatic changes in this record at AD 1–100 and AD 900–1050 seem to be broadly contemporaneous with major arid events from Lake Chichancanab, Mexico, affecting the Maya civilization and corroborated by the Quelccaya and Huascaran ice cores in Peru.