7 results on '"Pickering, Robyn"'
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2. Geological Setting and Age of Australopithecus sediba from Southern Africa
- Author
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Dirks, Paul H. G. M., Kibii, Job M., Kuhn, Brian F., Steininger, Christine, Churchill, Steven E., Kramers, Jan D., Pickering, Robyn, Farber, Daniel L., Mériaux, Anne-Sophie, Herries, Andy I. R., King, Geoffrey C. P., and Berger, Lee R.
- Published
- 2010
- Full Text
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3. U-Pb Dating Small Buried Stalagmites from Wonderwerk Cave, South Africa: a New Chronometer for Earlier Stone Age Cave Deposits.
- Author
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Pickering, Robyn
- Subjects
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URANIUM compounds , *LEAD compounds , *SPELEOTHEMS , *ARCHAEOLOGY , *CAVES - Abstract
Wonderwerk Cave, in the Northern Cape, South Africa, contains a long and much studied sequence of archaeological sediments and stone tool industries and is particularly known for its Earlier Stone Age (ESA) deposits. The paucity of well-dated ESA sites in South Africa, as well as question of the Fauresmith, seen as a transitional industry between the ESA and Middle Stone Age, make Wonderwerk Cave an important site. Uranium-lead (U-Pb) dating of speleothems is a relatively new chronometer, and ages for samples as small and fragmentary as the little buried stalagmites from Wonderwerk Cave help establish it as an imminent dating technique for archaeological sites. The key to successful U-Pb dating of these relatively young, buried stalagmites is thorough pre-screening. Laser ablation scans proved invaluable in identifying layers within the stalagmite suitable for U-Pb dating, as well as providing detailed trace element data, which exclude the possibility of diffusion absorption of U in or out of the samples and confirm the integrity of the U-Pb ages. The relationship between the small stalagmites and the sediments surrounding them is paramount to interpreting the ages. Given that stalagmites need a stable cave floor to form on, these samples will predate the sediments below them and are most likely coeval with the sediments surrounding them and as such provide close to maximum ages for these deposits. WW23 from stratum 5 at the base of excavation 2 has a U-Pb age of 0.548 ± 0.027 Ma. Two samples from stratum 10 from excavation 1, WW2 and WW4, have U-Pb ages of 0.734 ± 0.069 and 0.839 ± 0.026 Ma, respectively. These ages are precise enough to become a powerful tool to be used in pinning palaeomagnetic sequences and hint at a younger age of ~780 ka to 1.07 Ma for the older deposits, but a much larger data set is needed before this can be done with confidence. As it stands, these two ages suggest that there may be significant temporal variation within the stratum 10 deposits across the excavation area, and further work will be needed to constrain the chronology of the ESA deposits at Wonderwerk Cave. However, the addition of a new chronometer in the form of U-Pb dating adds an important new line of evidence for this complex task. As such, this technique will have broad applications for ESA cave sites older than 500 ka and beyond the limit of conventional uranium-thorium (U-Th) dating. Résumé: Wonderwerk Cave, dans le Northern Cape, Afrique du Sud, contient une séquence longue et très étudiée des sédiments archéologiques et les industries d'outils en pierre et est particulièrement connu pour ses précédentes âge de pierre (SEC ) des dépôts. La rareté des sites de l'ESA bien datés en Afrique du Sud, ainsi que la question de la Fauresmith, vu comme une industrie de transition entre l' ESA et du Middle Stone Age, font Wonderwerk Cave, un site important. Uranium-plomb (U-Pb) datant de concrétions est relativement nouveau chronomètre et âges des échantillons de petites et fragmentaires que les petites stalagmites enterrés de Wonderwerk Cave aider à établir comme une technique de datation imminent pour les sites archéologiques. La clé de la réussite datation U-Pb de ces relativement jeunes, stalagmites enterrés est approfondie présélection. Balayages laser d'ablation ont été précieuses dans l'identification des couches dans la stalagmite approprié pour datation U-Pb, ainsi que de fournir des données d'oligo-éléments détaillés, ce qui exclut la possibilité de diffusion-absorption de U ou sur des échantillons et de confirmer l'intégrité de l' U-Pb âges. La relation entre les petites stalagmites et les sédiments qui les entourent est primordiale pour l'interprétation des âges. Étant donné que les stalagmites ont besoin d'un sol de la grotte stable pour former sur ces échantillons antérieurs les sédiments sous eux et sont contemporains les plus susceptibles de les sédiments qui les entourent et en tant que tel, fournissent près de l'âge maximal pour ces dépôts. WW23 de la strate 5 à la base de Excavation 2 a un âge U-Pb de 0,548 ± 0,027 Ma. Deux échantillons de la strate 10 à partir de 1 Excavation, WW2 et WW4 ont âges U-Pb de 0,734 ± 0,069 0,839 ± Ma et 0,026 Ma, respectivement. Ces âges sont assez précises pour devenir un outil puissant pour être utilisé en épinglant séquences paléomagnétiques et signe à un plus jeune âge de ~ 780 ka à 1,07 Ma pour les dépôts plus anciens, mais un ensemble de données beaucoup plus importante est nécessaire avant que cela puisse se faire en toute confiance. À l'heure actuelle ces deux âges suggèrent qu'il peut y avoir variation temporelle significative dans la strate 10 dépôts à travers la zone d'excavation et d'autres travaux seront nécessaires pour contraindre la chronologie des dépôts de l'ESA à Wonderwerk Cave. Toutefois, l'ajout d'un nouveau chronomètre sous la forme de datation U-Pb ajoute une importante nouvelle source de données pour cette tâche complexe. Comme telle, cette technique aura applications larges ESA sites rupestres de plus que 500 ka et au-delà de la limite de l'uranium-thorium classique rencontres. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
4. A Mid-Pleistocene in situ fossil brown hyaena (Parahyaena brunnea) latrine from Gladysvale Cave, South Africa
- Author
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Berger, Lee R., Pickering, Robyn, Kuhn, Brian, Backwell, Lucinda, Hancox, Phillip J., Kramers, Jan D., and Boshoff, Pedro
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SEDIMENTS , *TOILETS , *CAVES , *BROWN hyena , *FOSSIL animals , *URANIUM-thorium dating , *PLEISTOCENE stratigraphic geology , *PLEISTOCENE paleogeography , *PLEISTOCENE paleoclimatology , *PLEISTOCENE paleoecology - Abstract
Abstract: An in situ fossil latrine is reported from Gladysvale Cave, South Africa. The latrine area is c. 1.5 m in observable horizontal length and varies in height with a maximum of 20 cm, indicating that deposition may have occurred over a considerable period of time. The size of individual coprolites in the latrine varies, with larger specimens >30 mm in diameter, but the majority generally smaller (c. 15–20 mm). The overall size and morphology of the coprolites and latrine are consistent with modern Parahyaena brunnea, which inhabit the caves today. Dated to between 195 and 257 ka, the latrine indicates that troglodytic latrine-making behaviour in P. brunnea may be traced to at least the Late Middle Pleistocene of southern Africa. [Copyright &y& Elsevier]
- Published
- 2009
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5. Probable human hair found in a fossil hyaena coprolite from Gladysvale cave, South Africa
- Author
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Backwell, Lucinda, Pickering, Robyn, Brothwell, Don, Berger, Lee, Witcomb, Michael, Martill, David, Penkman, Kirsty, and Wilson, Andrew
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FOSSIL hyenas , *ZOOARCHAEOLOGY , *HAIR , *COPROLITES , *ARCHAEOLOGICAL human remains , *CAVES - Abstract
Abstract: Until now, the oldest known human hair was from a 9000-year-old South American mummy. Here we report fossil hairs of probable human origin that exceed that age by about 200,000 years. The hairs have been discovered in a brown hyaena (Parahyaena brunnea) coprolite from Gladysvale cave in South Africa. The coprolite is part of a hyaena latrine preserved in calcified cave sediment dated between 195,000 and 257,000 years ago. This find supports the hypothesis that hyaenas accumulated some of the early hominin remains found in cave sites, and provides a new source of information on Pleistocene mammals in the Sterkfontein Valley. [Copyright &y& Elsevier]
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- 2009
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6. An Acheulean handaxe from Gladysvale Cave Site, Gauteng, South Africa.
- Author
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Hall, Grant, Pickering, Robyn, Lacruz, Rodrigo, Hancox, John, Berger, Lee R., and Schmid, Peter
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AXES , *BRECCIA , *FOSSILS , *CAVES , *ANTIQUITIES , *ARCHAEOLOGICAL excavations , *SEDIMENTS , *STRATIGRAPHIC paleontology , *ELECTRON spin resonance dating - Abstract
We Describe a single handaxe from fossiliferous breccias at Gladysvale Cave, South Africa. The artefact is the only known tool so far discovered during the controlled excavations conducted at this site over the last decade, and was recovered from decalcified sediments near the stratigraphic interface of two breccia units, making it difficult to assign it with confidence to either. The morphology of the handaxe indicates a middie-late Acheulean industry, and preliminary electron spin resonance and palaeomagnetic dating suggest an age of greater than 780 000 years. [ABSTRACT FROM AUTHOR]
- Published
- 2006
7. Dating correlated microlayers in oxalate accretions from rock art shelters: New archives of paleoenvironments and human activity.
- Author
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Green, Helen, Gleadow, Andrew, Levchenko, Vladimir A., Finch, Damien, Myers, Cecilia, McGovern, Jenna, Heaney, Pauline, and Pickering, Robyn
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ROCK art (Archaeology) , *CAVES , *CHARCOAL , *ACCRETION (Astrophysics) , *CARBON isotopes , *EARTH sciences , *INDUCTIVELY coupled plasma mass spectrometry , *ANIMAL tracks - Published
- 2021
- Full Text
- View/download PDF
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