Archives

TaqMan qPCR pushes boundaries for the analysis of millennial wood

Posted on January 28, 2017 by ARCAS

Publication date: March 2017Source:Journal of Archaeological Science, Volume 79 Author(s): Javier Gómez-Zeledón, Wolfgang Grasse, Fabian Runge, Alexander Land, Otmar SpringMillennial-old trees excavated from alluvial deposits or sampled from historical buildings are of high scientific value, e.g. for dating archeological wood as well as to reconstruct past climate variability. While chronologies are supported by isotopic measurements, climate reconstructions from year rings depend on reliable species identification and in some cases even specific populations should be differentiated. Such information could easily be provided by suitable DNA markers, given that DNA is available in appropriate amount and quality. Information from ancient DNA of wood remains is very scarce due to the difficulties in the extraction process, degradation of nucleic acids and the physical and chemical complexity of wood samples. We developed a new method to trace highly fragmented DNA by using a TaqMan qPCR assay, combined with a DNA extraction protocol specifically designed for wood. This approach resulted in a high rate of positive samples and provided sequence DNA information from subfossil oak wood up to 9000 years of age.

Read more

Are the intensities and durations of small-scale pottery firings sufficient to completely dehydroxylate clays? Testing a key assumption underlying ceramic rehydroxylation dating

Posted on January 28, 2017 by ARCAS

Publication date: March 2017Source:Journal of Archaeological Science, Volume 79 Author(s): Jonathan Paige, Kostalena Michelaki, Christopher Campisano, Michael Barton, Arjun HeimsathRehydroxylation (RHX) dating was recently suggested as a simple, cheap, and accurate method for dating ceramics. It depends on the constant rate of rehydroxylation (the slow reintroduction of OH) of clays after they are fired and dehydroxylated (purged of OH) during the production of pots, bricks, or other ceramics. The original firing of the ceramic artifact should set the dating clock to zero by driving all hydroxyls out of the clay chemical structure. To examine whether this assumption holds, especially for pot firings of short duration and low intensity, as those in small-scale traditional settings, we performed thermogravimetric analysis of clay samples of known mineralogy at temperatures and for durations reported from traditional sub-Saharan, American, and South Asian pottery firings. Results demonstrate that in the majority of samples, complete dehydroxylation (DHX) did not occur within, or even beyond, the conditions common in traditional firings. Consequently, between 0.01 and 1.5% of a sample’s mass in residual OH may remain after firings analogous to those observed in the ethnographic record. Lack of complete DHX at the scales we have observed can result in the over-estimation of ceramic ages by decades to tens of thousands of years, depending largely on the age of the sample, and the amount of residual OH present. Thus, in many cases, a key assumption underlying current RHX dating methods is unlikely to have been met, introducing considerable error in dates.

Read more

Editorial Board

Posted on January 26, 2017 by ARCAS

Publication date: February 2017Source:Journal of Archaeological Science, Volume 78

Read more

Archaeological formation theory and geoarchaeology: State-of-the-art in 2016

Posted on January 26, 2017 by ARCAS

Publication date: March 2017Source:Journal of Archaeological Science, Volume 79 Author(s): Ruth Shahack-GrossSince the influential work of Michael B. Schiffer on formation processes has been published in 1987, much has advanced on the part of environmental formation processes also known as N-transforms. Most new knowledge is the result of research conducted by geoarchaeologists. On the theoretical level, a huge leap forward was made with the realization that occupation deposits are artifacts of human activity. The focus of formation theory thus shifted from the artifact to the deposit. Methodological innovations and a geoarchaeological tool-kit, notably including the contextual technique of micromorphology, followed. Empirical studies of archaeological occupation deposits contributed new spatial and stratigraphic knowledge and understanding. A holistic middle-range methodology termed geo-ethnoarchaeology was developed, whereby macroscopic and microscopic artifacts are studied together with their associated sediments in ethnographic contexts, providing contextual (social) information about the relationship between artifacts and the surrounding sediments as archaeological assemblages form. This method is especially powerful when sequentially dated abandoned settlements or features are studied to provide mechanistic understanding of assemblage and/or site formation through degradation. Because geo-ethnoarchaeology is based on general chemical, biological and physical laws, the resultant mechanistic models are applicable globally, for any time period, culture, and environment. The new tools and mechanistic understanding by which N-transforms are currently studied, provide means to more reliably interpret the archaeological record, which is crucial for the credibility of archaeology. Therefore, when studying archaeological assemblages one should utilize the tool-kit developed by geoarchaeologists to first assess the states of preservation of the various material assemblages (macroscopic and microscopic), as it should be borne in mind that assemblages identified to be well-preserved will produce the most reliable archaeological interpretation. The theory and method of geoarchaeology have matured enough to allow responsible archaeological research into the meaning of spatial and temporal (stratigraphic) patterns at any given site.

Read more

Environmental reconstruction and dating of Shizitan 29, Shanxi Province: An early microblade site in north China

Posted on January 23, 2017 by ARCAS

Publication date: March 2017Source:Journal of Archaeological Science, Volume 79 Author(s): Yanhua Song, David J. Cohen, Jinming Shi, Xiaohong Wu, Eliso Kvavadze, Paul Goldberg, Shuangquan Zhang, Yue Zhang, Ofer Bar-YosefGlobal cooling during the Last Glacial Maximum (LGM) posed significant challenges to peoples living in northern Eurasia. Using micromorphology, pollen and non-pollen palynomorphs (NPP), and faunal analyses, this study reconstructs the local paleoenvironmental contexts of repeated ephemeral occupations at Shizitan 29 in Shanxi Province, North China, across the LGM, from ca. 28 to 18 Ka cal BP, followed by a gap until a final occupation ca.13.5 Ka cal BP. Among the significant finds at Shizitan 29 are remains of 285 hearths and a rich lithic assemblage that contains the earliest radiocarbon-dated evidence for microblades in China, appearing first in Layer 7. The environmental data show that the low mountains and tributary river valleys of the Yellow River in the Loess Plateau provided abundant sources of water and food in spite of environmental fluctuations. Microblade-producing groups repeatedly visiting this locality survived severe climate change by making use of fire, selective herbivore hunting, processing plant foods with grinding stones, and symbolic ornamentation such as ostrich shell beads. NPP data also indicate the potential presence of flax and other fiber processing. The Shizitan 29 data demonstrate how humans adapted to challenging local conditions throughout the LGM, allowing them to stay within this northerly region without migrating to warmer southern latitudes.

Read more

Ancient DNA analysis of cyprinid remains from the Mesolithic-Neolithic Danube Gorges reveals an extirpated fish species Rutilus frisii (Nordmann, 1840)

Posted on January 21, 2017 by ARCAS

Publication date: March 2017Source:Journal of Archaeological Science, Volume 79 Author(s): Ivana Živaljević, Danijela Popović, Aleš Snoj, Saša MarićThe paper presents and discusses the results of the first ancient DNA (aDNA) analysis of cyprinid remains recovered from the Mesolithic-Neolithic sites of Vlasac, Lepenski Vir and Padina in the Danube Gorges (North-Central Balkans). Cyprinids constitute a significant portion of the identified fish remains recovered from these sites, which is indicative of their dietary role, and their large pharyngeal teeth have been worn as garment appliqués and associated with a great number of buried individuals. aDNA analysis (involving mitochondrial and nuclear markers) of pharyngeal bones with teeth corresponding to those used as appliqués has determined that they originate from anadromous Rutilus frisii (vyrezub), previously unrecorded in the Middle and Lower Danube. At present, the species inhabits the Black, Azov and Caspian Sea basins, but the only known populations in the Danube inhabit solely its upper reaches in Austria. The results of our study and the occurrence of R. frisii in the Danube Gorges further corroborate that its Upper Danube and Black Sea habitat had been connected in the past, i.e. that the species was entering the whole stretch of the river during its spawning migrations. Furthermore, precise taxonomic identification has important implications for a better understanding of fishing practices and their seasonal schedule in the Danube Gorges, and the distribution of cyprinid pharyngeal teeth ornaments in Europe during the Mesolithic.

Read more

Ritual complexity in a past community revealed by ancient DNA analysis of pre-colonial terracotta items from Northern Ghana

Posted on January 21, 2017 by ARCAS

Publication date: March 2017Source:Journal of Archaeological Science, Volume 79 Author(s): Heather A. Robinson, Timothy Insoll, Benjamin W. Kankpeyeng, Keri A. Brown, Terence A. BrownThe pre-colonial 6th–14th century terracotta forms of Koma Land, Northern Ghana, contain cavities which may have been intended to hold liquids. These have been linked to traditional African libation, but the specific nature of their contents is unclear. We used generic polymerase chain reactions that would amplify DNA from a range of plant and fungal species in order to identify remains of libations applied to fourteen terracotta items. We anticipated difficulties in distinguishing genuine ancient DNA sequences from those resulting from contaminating material, and therefore also carried out a series of control experiments to assess the extent to which the samples had become contaminated with exogenous DNA during burial, excavation and downstream analysis. Taking account of the results of the control experiments, as well as the difficulties in assigning matches between ancient DNA sequences and database entries, we provide evidence for the use of three different types of plant – plantain/banana, pine and grasses – in libations associated with the terracotta items. We also identified DNA from Coniochaeta yeast within the mouth cavity of one figurine, suggesting that this structure was burnt prior to deposition.

Read more

Post-depositional alteration of humid tropical cave sediments: Micromorphological research in the Great Cave of Niah, Sarawak, Borneo

Posted on January 14, 2017 by ARCAS

Publication date: January 2017Source:Journal of Archaeological Science, Volume 77 Author(s): M. Stephens, J. Rose, D.D. GilbertsonThe post-depositional alteration of cave sediments is of critical importance for the recognition, identification and investigation of geoarchaeological and palaeoenvironmental evidence. There have been relatively few studies of tropical cave sediments using micromorphology and this work represents one of the most detailed with 26 samples taken from deposits in the West Mouth of the Great Cave of Niah that cover the last >∼55,000 BP, and contain the earliest known evidence for the remains of modern humans in Southeast Asia. Cave sediments situated in the humid tropics are subject to relatively high temperatures and moisture conditions that promote high rates of chemical alteration and geomorphic change. This paper outlines those post-depositional features that occurred in situ in the West Mouth and include: translocation and concentration; bioturbation; excrement; bone alteration; plant alteration; clast alteration and guano decomposition. It examines their implications for recognising past human activities (e.g. fire-altered materials), the preservation of archaeological remains, the nature of palaeoenvironments and of localised physical and bio-geochemical processes.

Read more

Approaches to Middle Stone Age landscape archaeology in tropical Africa

Posted on January 14, 2017 by ARCAS

Publication date: January 2017Source:Journal of Archaeological Science, Volume 77 Author(s): David K. Wright, Jessica C. Thompson, Flora Schilt, Andrew S. Cohen, Jeong-Heon Choi, Julio Mercader, Sheila Nightingale, Christopher E. Miller, Susan M. Mentzer, Dale Walde, Menno Welling, Elizabeth Gomani-ChindebvuThe Southern Montane Forest-Grassland mosaic ecosystem in the humid subtropics southern Rift Valley of Africa comprised the environmental context for a large area in which modern human evolution and dispersal occurred. Variable climatic conditions during the Late Pleistocene have ranged between humid and hyperarid, changing the character of the ecosystem and transforming it at different points in time into a barrier, a refuge, and a corridor between southern and eastern African populations. Alluvial fans presently blanket the areas adjacent to major river systems, which were key areas of prehistoric human habitation. These sets of variables have created conditions that are both challenging and advantageous to conduct archaeological research. Lateritic soil development has resulted in poor organic preservation and facilitated insect bioturbation, which has demanded an integrated micro-macro scale approach to building a reliable geochronology. An integrated field and analytical methodology has also been employed to identify the nature and degree of post-depositional movement in alluvial deposits, which preserve a wide range of spatial integrity levels in buried stone artifact assemblages between 47 and 30 ka in Karonga, northern Malawi. This paper describes the methodological advances taken toward understanding open-air Middle Stone Age archaeology in sub-tropical Africa, and explores the inferential potential for understanding Pleistocene human ecology in the important southern Rift Valley region.

Read more

Editorial Board

Posted on January 14, 2017 by ARCAS

Publication date: January 2017Source:Journal of Archaeological Science, Volume 77

Read more