Browsing by Author "Pike, Alistair W.G."
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- Dating Palaeolithic cave art: Why U–Th is the way to goPublication . Pike, Alistair W.G.; Hoffmann, Dirk L.; Pettitt, Paul B.; García-Diez, Marcos; Zilhão, JoãoThe chronology of European Upper Palaeolithic cave art is poorly known. Three chronometric techniques are commonly applicable: AMS 14C, TL and UeTh, and in recent years the efficacy of each has been the subject of considerable debate. We review here the use of the UeTh technique to date the formation of calcites that can be shown to have stratigraphic relationships to cave art. We focus particularly on two recent critiques of the method. By using specific examples from our own work using this method in Spain, we demonstrate how these critiques are highly flawed and hence misleading, and we argue that the UeTh dating of calcites is currently the most reliable of available chronometric techniques for dating cave art.
- Methods for U-series dating of CaCO 3 crusts associated with Palaeolithic cave art and application to Iberian sitesPublication . Hoffmann, Dirk L.; Pike, Alistair W.G.; García-Diez, Marcos; Pettitt, Paul B.; Zilhão, JoãoU-series dating is a precise and accurate geochronological tool which is widely applied to date secondary CaCO3 formation, for example in speleothem based palaeoclimate research. It can also be employed to provide chronological constraints for archaeological sites which have a stratigraphic relationship with speleothem formations.We present in detail our methods to conduct precise and accurate U-Th dating of calcite crusts that formed on top of cave paintings. Our protocols allow the application of U-series measurements on small, thin calcite crusts covering cave art, which can be found in many sites, while taking care not to harm the art underneath. The method provides minimum ages for the covered art and, where possible, also maximum ages by dating the flowstone layer the art is painted on. We present dating results for crusts from two locality types in Spain, a typical cave environment (La Pasiega) and a more open, rock shelter type cave (Fuente del Trucho).
- New U-series results for the speleogenesis and the Palaeolithic archaeology of the Almonda karstic system (Torres Novas, Portugal)Publication . Hoffmann, Dirk L.; Pike, Alistair W.G.; Wainer, Karine; Zilhão, JoãoThe Almonda karstic system is an extensive network of cavities associated with the spring of the Almonda River. Among those of archaeological interest, the lowermost, 5e15 m above the current spring, contain deposits of Upper Palaeolithic and Holocene age. Higher up in a 70 m high escarpment, the labyrinth of passages features several collapsed cave entrances, two of which have been cleared for archaeological excavation: the Gruta da Aroeira/Galerias Pesadas/Brecha das Lascas complex of Acheulean localities, and the Middle Palaeolithic site of Gruta da Oliveira. U-series dating of speleothems associated with these deposits places the Acheulean of the Almonda beyond 390 ka, dates the palaeophreatic level of w40 m above the extant outlet back to a time before 200 ka, and constrains the accumulation of the Gruta da Oliveira sediment fill to between 23 ka and at least 102 ka. Bones from Gruta da Oliveira layer 8, which contains the uppermost human occupation of the site, were dated to the 34e40 ka range by U-series (Diffusion/Adsorption), in good agreement with available radiocarbon results. Combined with evidence from other sections of the system, these results set at half a million years ago or more the earliest human settlement of the Atlantic façade of Iberia, provide the first secure chronometric evidence for the emergence of the Acheulean in the peninsula (during Marine Isotope Stage 12 at the latest), and support the regional persistence of a Neanderthal-associated Middle Palaeolithic beyond 41.5 ka (the time of emergence elsewhere in western and central Europe of the Protoaurignacian, widely assumed to be modern human-related). U-series dating of speleothems collected in the inner passages of the system suggests uninterrupted speleothem formation through the Middle and Upper Pleistocene, enabling the construction of a high-resolution continental palaeonvironmental record for comparison with the evidence from the deep sea cores obtained off the Portuguese coast.
- Response to Aubert et al.'s reply ‘Early dates for ‘Neanderthal cave art’ may be wrong’ [J. Hum. Evol. 125 (2018), 215–217]Publication . Hoffmann, Dirk L.; Standish, Christopher D.; García-Diez, Marcos; Pettitt, Paul B.; Milton, James A.; Zilhão, João; Alcolea-González, Javier J.; Cantalejo-Duarte, Pedro; Collado, Hipolito; de Balbín, Rodrigo; Lorblanchet, Michel; Ramos-Muñoz, Jose; Weniger, Gerd-Christian; Pike, Alistair W.G.
- Response to White et al.’s reply : ‘Still no archaeological evidence that Neanderthals created Iberian cave art’ [J. Hum. Evol. (2020) 102640]Publication . Hoffmann, Dirk L.; Standish, Christopher D.; García-Diez, Marcos; Pettitt, Paul B.; Milton, James A.; Zilhão, João; Alcolea-González, Javier J.; Cantalejo-Duarte, Pedro; Collado, Hipolito; de Balbín, Rodrigo; Lorblanchet, Michel; Ramos-Muñoz, Jose; Weniger, Gerd-Christian; Pike, Alistair W.G.
- U-series dating of Palaeolithic rock art at Fuente del Trucho (Aragón, Spain)Publication . Hoffmann, Dirk L.; Utrilla, Pilar; Bea, Manuel; Pike, Alistair W.G.; García-Diez, Marcos; Zilhão, João; Domingo, RafaelThis paper concerns the dating of the Palaeolithic rock art of the Fuente del Trucho cave. We used the U-Th method to date calcite crusts superimposed to the paintings. Whenever sub-samples of a single crust could be dated we obtained stratigraphically consistent results and the correction for detrital contamination is negligible. Our results are strictly reliable as minimum ages and suggest that the decoration of this site is of a Gravettian or earlier age, even though a Solutrean chronology cannot be excluded in a few cases. These results are upheld by stylistical comparison with Spanish and French parietal and mobiliary art.
- Uranium series dating reveals a long sequence of rock art at Altamira Cave (Santillana del Mar, Cantabria)Publication . García-Diez, M.; Hoffmann, Dirk L.; Zilhão, João; Heras, C. de las; Lasheras, J.A.; Montes, R.; Pike, Alistair W.G.The rock art in Altamira Cave was the first ensemble of Palaeolithic parietal art to be identified scientifically (Sautuola, 1880). Due to the great thematic, technical and stylistic variety of the art in the cave, which constitutes one of the most complete Palaeolithic art ensembles, Altamira was listed as World Heritage by UNESCO in 1985. Uranium-series dating has recently been applied to figures on the decorated ceiling in the cave. Several motifs are partly covered by thin layers of calcite precipitates, whose formation process is datable by this method. The results provide the date when the calcite formed, which gives a minimum age for the underlying depictions. These results confirm that the parietal art at Altamira was produced during a prolonged period of time, at least 20,000 years (between 35,000 and 15,200 years ago), and that part of the ensemble corresponds to the Aurignacian period.