Picture Cave (23WN79): Pictograph Chronology

To determine the chronology of the imagery and iconography at Picture Cave in the Missouri River Valley, we radiocarbon dated 16 additional pictographs using plasma oxidation and accelerator mass spectrometry. Bayesian chronological modeling estimates that pictograph production began between cal AD 85 and 530 and ended in cal AD 1325–1630 , with a duration of 905–1480 years (95.4% probability). Although the majority of pictographs were produced during the Late Woodland and Early Mississippian periods, one age is within the Middle Woodland period, and two of the pictographs were created during the Middle Mississippian or Late Mississippian periods. X-ray diffraction identified graphitic carbon as pyrolyzed carbon for black paintings and drawings and hematite and goethite iron minerals for red pictographs on the sandstone rock substrate. Given its multiple visitations over time, Picture Cave is a persistent sacred place within the landscape.