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| DOI | 10.1016/j.quascirev.2019.06.037 |
| 230Th/U burial dating of ostrich eggshell | |
| Sharp W.D.; Tryon C.A.; Niespolo E.M.; Fylstra N.D.; Tripathy-Lang A.; Faith J.T. | |
| 发表日期 | 2019 |
| ISSN | 0277-3791 |
| 起始页码 | 263 |
| 结束页码 | 276 |
| 卷号 | 219 |
| 英文摘要 | Obtaining precise and accurate dates for late Quaternary terrestrial sequences containing Middle Stone Age or Middle Paleolithic archaeological materials (ca. 30–300 ka) can be challenging. Many such sequences lie beyond the limit of radiocarbon dating (∼50 ka) and lack volcanic ashes suitable for 40Ar/39Ar dating. We report a dating approach with about ten times the range of radiocarbon dating (∼500 ka) based on a novel protocol for 230Th/U dating of ostrich eggshell, a common component of African, Near Eastern and Asian archaeological sequences. Uranium in ostrich eggshell, typically at levels of tens to hundreds of ppb, is acquired after burial. However, accurate burial ages can be determined from measured 230Th/U ages when corrected for uranium uptake via diffusion. Using ostrich eggshells from a Pleistocene-Holocene east African site, we have: (1) characterized the spatial distribution of uranium and common thorium (232Th) concentrations in ostrich eggshell by laser ablation ICP-MS, (2) determined apparent 230Th/U ages on outer and inner layers of eggshells by solution ICP-MS analyses of selectively abraded eggshells, and (3) calculated 230Th/U burial ages using a simple model for diffusive uptake of uranium. We assess our method by comparing the 230Th/U burial ages (median uncertainty 2.3%, 1 SD) with radiocarbon dates on carbonate from the same eggshells. We find good agreement in seven out of nine eggshells, confirming the accuracy of their 230Th/U model ages. Eggshells that fail to yield reliable 230Th/U ages may be recognized by anomalous patterns of apparent 230Th/U ages, providing a reliability criterion innate to the 230Th/U data. Ostrich eggshells are resistant to diagenesis simplifying 230Th/U dating compared to bones and teeth. Eggshells of ostrich, emu, rhea and other living and extinct ratites found on six continents share similar structure and composition, suggesting our new approach to 230Th/U dating of eggshell may be applicable in diverse late Quaternary terrestrial settings. © 2019 Elsevier Ltd |
| 英文关键词 | Africa; Archaeology; Geochronology; Later stone age; Middle stone age; Ostrich eggshells; Pleistocene; Ratite eggshells; U-series |
| 语种 | 英语 |
| scopus关键词 | Geochronology; Inductively coupled plasma mass spectrometry; Laser ablation; Mass spectrometers; Uncertainty analysis; Uranium; Volcanoes; Africa; Archaeology; Ostrich eggshells; Pleistocene; Ratite eggshells; Stone age; U-series; Birds; archaeology; eggshell; geochronology; Mesolithic; Paleolithic; Pleistocene-Holocene boundary; Quaternary; radiocarbon dating; spatial distribution; terrestrial environment; uranium series dating; Africa; Asia; Palaeognathae; Rhea; Struthioniformes |
| 来源期刊 | Quaternary Science Reviews
 |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/151820 |
| 作者单位 | Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, United States; Department of Anthropology, Harvard University, Cambridge, MA 02138, United States; Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, United States; Natural History Museum of Utah and Department of Anthropology, University of Utah, Salt Lake City, UT 84108, United States |
| 推荐引用方式 GB/T 7714 | Sharp W.D.,Tryon C.A.,Niespolo E.M.,et al. 230Th/U burial dating of ostrich eggshell[J],2019,219. |
| APA | Sharp W.D.,Tryon C.A.,Niespolo E.M.,Fylstra N.D.,Tripathy-Lang A.,&Faith J.T..(2019).230Th/U burial dating of ostrich eggshell.Quaternary Science Reviews,219. |
| MLA | Sharp W.D.,et al."230Th/U burial dating of ostrich eggshell".Quaternary Science Reviews 219(2019). |
| 条目包含的文件 | 条目无相关文件。 | |||||
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