Recent multidisciplinary research indicates that prehistoric agriculture innovation promoted permanent human settlements of areas up to 3400 m above sea level (asl) in the northern Tibetan Plateau, but when and how ancient humans extensively occupied areas above that altitude remains uncertain. In this paper, we investigated 12 archaeological sites situated above 3600 m asl in the Yushu autonomous prefecture, east-central Tibetan Plateau, to explore this issue. We determined the ages of five sites using the radiocarbon (14C) dating method and identified animal bones sampled from three sites. The dating results show that humans occasionally occupied the Yushu area around 900 BC, and permanently inhabited the area between AD 540 and 1620. Preliminary faunal identifications indicate human-raised livestock including yak, sheep, and horse during the latter period. Stone-constructed tombs and rock painting were found at some investigated sites, suggesting humans perhaps engaged in a pastoral lifestyle during the very late Holocene in the high altitude Yushu area, where nomadic livestock production remains the current primary subsistence strategy focus.

Using plasma chemistry, carbon was extracted from charcoal paint samples collected from megalithic monuments in north-west Iberia. Nine accelerator mass spectrometric radiocarbon dates on these paints establish their age to be within 1000 14C years of each other, centred at approximately 5000 BP. These radiocarbon ages for megalithic paintings fall within the proposed time period for north-west Iberian megalithic culture. Multiple layers of paint on some stones show that more than one painting episode occurred.