Refining the Paleo-Aleut to Neo-Aleut transition using a new ΔR for the eastern Aleutian Islands, Alaska

Using six paired terrestrial and marine organics collected in the Islands of Four Mountains, Alaska, we present a new regional correction factor, ΔR (495±20 yr), for the eastern Aleutians. We compare our ΔR with previous North Pacific marine corrections. Using the ΔR for the eastern Aleutians, we calibrated the radiocarbon dates of 80 human skeletons recovered from village site Chaluka and cave burials at Ship Rock and Kagamil Islands. These burial places contain two morphologically and genetically distinct humans—an early form called Paleo-Aleut and a later form called Neo-Aleut. Researchers have contested (1) the timing of Neo-Aleut movements into the Aleutians, and (2) Neo-Aleut interactions with Paleo-Aleuts. Our recalibrations indicate that the oldest Paleo-Aleut burial (1135 BC) occurred at Chaluka and the youngest Paleo-Aleut cave burial occurred at Kagamil during the fourteenth century (AD 1305). Neo-Aleuts buried their dead at Chaluka by AD 1375. The oldest definitive Neo-Aleut cave burial occurred during the fifteenth century (AD 1420) at Ship Rock. Eastern Aleuts buried their dead in caves for centuries, with the youngest Neo-Aleut buried at Kagamil circa AD 1865.