One of the prominent features in sediment sequences formed around the AllerOd-Younger Dryas transition (c. 12.9-12.8 ka bp) in North America is a dark layer of organic-rich material, i.e. the black mat. The black mat sequences in southeast Arizona contain a thin sandy basal layer corresponding to the lower Younger Dryas boundary. Trace element concentrations in the lower Younger Dryas boundary sediments, in the black mat, in the host sediments, and in charcoal from Western Europe and southeast Arizona were studied using LA-ICP-MS. The black mat samples and samples of the underlying host sediments display compositions similar to the average continental crust, while the sediments from the lower Younger Dryas boundary are enriched in rare earth elements, Ni, and Co whereas Ta, Nb, Zr, and Hf are depleted relative to the rare earth elements. Such a difference in compositions between the lower Younger Dryas boundary sediments and other sediments points to a short enigmatic event, which changed conditions of sedimentation just before the onset of the Younger Dryas cooling. The presence of products of biomass burning of still unknown origin is suggested on the basis of trace element features of sediments from the lower Younger Dryas boundary.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/621537 |
| Date | 09 1900 |
| Creators | ANDRONIKOV, ALEXANDRE V., ANDRONIKOVA, IRINA E. |
| Contributors | Univ Arizona, Dept Geosci, Univ Arizona, Lunar & Planetary Lab, Department of Geosciences; University of Arizona; Tucson AZ USA, Lunar and Planetary Laboratory; University of Arizona; Tucson AZ USA |
| Publisher | WILEY-BLACKWELL |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | © 2016 Swedish Society for Anthropology and Geography |
| Relation | http://doi.wiley.com/10.1111/geoa.12132 |
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