The composition reported here is the average of analyses of five samples: UA1147, UA1197, UA1476, UA1477, and UA1478. Tephra bed found at Site B, within both the paleomagnetic transect (UA1147,1197) and at an adjacent gully (UA1477, 1478), and at Site D2 (UA1476). At all three sites it is found within the MIS 5e forest bed (~28-30 m above river level; ~45 m at Site D2), which contains large Picea logs that are locally upright and rooted (Reyes and others, 2010). The tephra is white to pink, and is present as discontinuous pods up to 1 cm thick. Glass shards are typically tri-cuspate or bubblewalled. Pumice is also present and commonly elongate, and brown glass is present. Mineralogy consists largely of orthopyroxene and plagioclase.
The Palisades is a key reference site for the middle Pleistocene of eastern Beringia: new evidence from paleomagnetics and regional tephrostratigraphy
This website is supported by the U.S. Geological Survey under Cooperative Agreement Grant G22AC00137
Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.