New Radiocarbon Dates from Nasera Rockshelter (Tanzania): Implications for Studying Spatial Patterns in Late Pleistocene Technology

Late Pleistocene and Holocene evidence from multiple rockshelters in north-central Tanzania suggests a regional pattern of changing technological behaviors through time. We use independent chronological evidence to test if the proposed technological patterns across space were also temporally equivalent. We applied AMS radiocarbon dating methods to the carbonate fraction of five ostrich eggshell fragments from Mehlman's 1975-1976 excavations at Nasera rockshelter and compared our results to recent re-dating efforts of Mumba rockshelter. We document radiocarbon results >46 ka at Nasera in Level 5, indicating that associated and underlying technologies (including what Mehlman termed the 'Nasera Industry') are older than previously documented. Backed pieces first appear >46 ka at Nasera, which is in accordance with recent evidence from nearby rockshelters like Enkapune ya Muto, Panga ya Saidi, and potentially Kisese II. We also provide an age of 11,260-11,710 calBP for the 'Silale Industry' of Level 3B. Overall, the shifts in lithic technology previously considered to be shared between Mumba and Nasera rockshelters are not temporally aligned, emphasizing the possibility that intra-site variability was the norm throughout the Late Pleistocene in eastern Africa.