Uranium-series age estimates for rock art in southwest China

We report the first uranium-series age estimates for rock art in China. Calcite bracketing a paint layer was used to constrain the age of a naturalistic outline hunter-gatherer painting in the Jinsha River area of northwest Yunnan Province (southwest China). The rock paintings in this region are unique in style and content compared with other bodies of rock art in China, which are dominated by Neolithic subject matter. The minimum and maximum ages were determined using isochron techniques on multiple samples of calcite from above and beneath the paint layer. A large painted deer head was dated to between 5738 and 2050 years. This painting and underlying flowstone are superimposed on older paintings that suggest the older paintings are at least 3400 years old, if not older than 5738 years. The results indicate for the first time that Jinsha River rock art is older than other forms of rock art in the region and show that rock art likely extends back to at least the transition from the Palaeolithic to Neolithic in this part of China.     

辽宁本溪庙后山遗址铀系测年初步结果

庙后山是位于我国东北的重要中更新世人类遗址。报道该地点出土人类化石的第5、6堆积层次生碳酸盐岩和骨化石样的铀系测年结果。夹生于第6堆积层3个钙板的年龄分别为276、>535、346ka,其下第5层中的钙板为526±31ka,据此第6层顶部应至少为200ka,第5层中部应大于500ka。结果远大于该地点原基于骨化石铀系测年的年代框架,支持中国直立人和早期智人交替比原认为约200ka早得多的观点。     

Laser ablation depth profiling of U-series and Sr isotopes in human fossils

We have explored laser depth profiling to obtain data sets for U-series as well as Sr analyses. Laser probing with an 81 μm spot size allows for the exploration of low uranium domains of up to 400 μm below the outer surface in tooth enamel. These low U domains will contain Sr isotope compositions of the individual, that are least affected by diagenetic Sr overprints. The small holes drilled for U surveying are not visible to the naked eye. Using larger spot sizes of around 233 μm, laser drilling can be used to obtain reliable U-series isotope data to a depth of approximately 1000 μm in enamel and around 1300 μm in bone. Furthermore, meaningful ⁸⁷Sr/⁸⁶Sr isotope data can also be obtained with this spot size. Using our sampling strategy, the overall damage to a human tooth is minute, as demonstrated on a Neanderthal tooth from Moula-Guercy. We expect that laser ablation depth profiling will become routine for gaining insights into the age of human fossils and the migrations of ancient humans.     

U-series and radiocarbon dates on mollusc shells from the uppermost layer of the archaeological site of KHB-1, Ra's al Khabbah,Oman

The archaeological site of KHB-1, Oman, has been investigated in order to improve the chronological knowledge of the site, which is dated to the beginning of the fourth millennium B.C. on the basis of the archaeological context. Mollusc shells of the genus Anadara, coming from the uppermost layers of the site, have been dated using two different methods, radiocarbon and U-series technique. The results of the two techniques date the last occupational phase of the site from the end of the fourth millennium B.C. to the beginning of the third millennium B.C.     

Radiocarbon and U-series dating of the endemic deer Praemegaceros cazioti (Depéret) from “Grotta Juntu”, Sardinia

Radiocarbon and U-series methods (²³⁰Th/U and ²³¹Pa/²³⁵U) for absolute age determination have been applied to some fossil samples from Grotta Juntu, in North Eastern Sardinia (Italy). The remains belong to the endemic deer species Praemegaceros cazioti, which is here represented by an almost complete skeleton. The three dating methods lead to concordant ages of about 7500 years BP, indicating that the skeleton was maintained as closed system after burial. Taking into consideration these results, Praemegaceros cazioti from Grotta Juntu is now the youngest representative of this species in Sardinia.     

Mass spectrometric U-series dating of Laibin hominid site in Guangxi, southern China

The Laibin hominid represents one of the rare finds of modern Homo sapiens in China, rare for its relative completeness and well-established stratigaphic provenance. This paper presents the results of mass spectrometric U-series dating of intercalated calcite samples from the Laibin site. The capping flowstone and the calcite vein, which sandwich the hominid fossil-containing deposits, date to 38.5 ± 1.0 and 44.0 ± 0.8 ka, setting respectively the minimum and maximum ages to the fossils. The second flowstone layer is 112.0 ± 1.4 ka old, indicating that the cultural sequence may possibly extend to somewhere between 44 and 112 ka. Securely dated Laibin finds should be of importance in reconstructing human physical and cultural evolution in the region.     

江苏溧水神仙洞动物化石的铀系年代

神仙洞是江苏境内最早发现人类化石的地点。报道该地点动物化石的铀系测年结果,4个样品230Th/234U年龄范围为7～109ka,测定了其中2个样品的227Th/230Th年龄,结果与230Th/234U法的一致,支持年代数据的可信度。暂将神仙洞含化石堆积的年代定为7～109ka,跨度至少100ka,应比原认为的整体距今～10ka合理得多。但洞穴地点骨化石铀系年代总体偏年轻,上述年代范围很可能被低估,含化石堆积底界因此更可能属中更新世晚期。人颞骨化石被认为出土于第I钙板层之上,应为晚更新世末期或全新世早期。用Gamma能谱铀系或AMS14C测年,应可进一步确定人化石的年代。