News

Investigation of organic matter and biomarkers from Diepkloof Rock Shelter, South Africa: Insights into Middle Stone Age site usage and palaeoclimate

Posted on July 21, 2017 by ARCAS

Publication date: September 2017Source:Journal of Archaeological Science, Volume 85 Author(s): James A. Collins, Andrew S. Carr, Enno Schefuß, Arnoud Boom, Judith SealyDiepkloof Rock Shelter (DRS) represents a site of major interest for reconstructing early human behaviours during the Middle Stone Age (MSA). Rock shelters such as DRS also potentially preserve information concerning the environmental context for such behaviours. In this respect the organic matter composition of rock shelter sediments has rarely been investigated in detail, particularly at the molecular level. Here, we used pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) to systematically assess the organic matter composition of bulk sediments within the MSA and Later Stone Age (LSA) sequence at DRS. From this we sought to gain insights into site usage, taphonomy and burning practices. Additionally, we analysed the chain length distribution of leaf-wax n-alkanes as well as their hydrogen and carbon isotopic compositions (δDwax and δ13Cwax) to investigate their potential as hydroclimate and vegetation indicators. This constitutes the first leaf-wax isotopic data in a terrestrial context of this antiquity in South Africa.Py-GC/MS shows a dichotomy between stratigraphic units (SUs) of high organic matter content, producing a range of pyrolysis products, including homologous series of long chain n-alkene/n-alkane doublets and alkyl-nitriles, and SUs of low organic matter content, dominated by aromatic, heterocyclic N and polycyclic aromatic hydrocarbon (PAH) pyrolysis products; typical molecular burning products. Several SUs of the Intermediate Howiesons Poort interval exhibit the latter composition, consistent with micromorphological evidence.δ13Cwax remains stable throughout the MSA, but leaf-wax n-alkane chain length and δDwax increase during the Late Howiesons Poort interval. Comparison with such patterns in modern plants in the region suggests this represents a shift towards the input of more arid-adapted vegetation into the shelter, driven either by aridification at the site locale or a change in selection practices. Our results suggest that these techniques have further potential in southern Africa and globally at sites where organic matter preservation is high.

Read more

Geospatial Big Data and archaeology: Prospects and problems too great to ignore

Posted on July 12, 2017 by ARCAS

Publication date: Available online 11 July 2017Source:Journal of Archaeological Science Author(s): Mark D. McCoyAs spatial technology has evolved and become integrated in to archaeology, we face a new set of challenges posed by the sheer size and complexity of data we use and produce. In this paper I discuss the prospects and problems of Geospatial Big Data (GBD) – broadly defined as data sets with locational information that exceed the capacity of widely available hardware, software, and/or human resources. While the datasets we create today remain within available resources, we nonetheless face the same challenges as many other fields that use and create GBD, especially in apprehensions over data quality and privacy. After reviewing the kinds of archaeological geospatial data currently available I discuss the near future of GBD in writing culture histories, making decisions, and visualizing the past. I use a case study from New Zealand to argue for the value of taking a data quantity-in-use approach to GBD and requiring applications of GBD in archaeology be regularly accompanied by a Standalone Quality Report.

Read more

A landmark-based approach for assessing the reliability of mandibular tooth crowding as a marker of dog domestication

Posted on July 11, 2017 by ARCAS

Publication date: September 2017Source:Journal of Archaeological Science, Volume 85 Author(s): Carly Ameen, Ardern Hulme-Beaman, Allowen Evin, Mietje Germonpré, Kate Britton, Thomas Cucchi, Greger Larson, Keith DobneyTooth crowding is one of several criteria used to infer the process of domestication in the zooarchaeological record. It has been primarily used to support claims of early animal domestication, perhaps most contentiously in claims for the existence of so-called “proto-domestic” dogs as early as the Middle-Upper Palaeolithic. Tooth crowding studies vary in their methodological approaches, and interpretation of the resulting data is constrained by the limited geographic and temporal scope of reference specimens used to construct an appropriate comparative framework. To address these key problems, we present a standardised landmark-based protocol for the measurement and quantification of mandibular tooth crowding that can be systematically applied in the context of dog domestication research. We then test the assumption that tooth crowding is less frequent in ancient and modern wild wolf populations by examining 750 modern dogs and 205 modern wolves from across the modern geographic range of Canis lupus as well as 66 Late Pleistocene wolves from Alaska.Our results demonstrate that landmark-based metrics provide a reliable approach for recording and analysing tooth crowding. Although it is likely that the relatively low frequency of tooth crowding found in our modern dog dataset (∼6%) in part reflects the ‘modern’ morphology of domestic breeds, the higher frequency of crowding in both modern (∼18%) and ancient (∼36%) wolves strongly suggests that current assumptions linking tooth crowding with the process of early domestication (at least in dogs) should be critically re-evaluated, and that further investigations into the drivers behind these developmental patterns should be pursued.

Read more

Cautionary tales on the identification of caffeinated beverages in North America

Posted on July 9, 2017 by ARCAS

Publication date: September 2017Source:Journal of Archaeological Science, Volume 85 Author(s): Adam King, Terry G. Powis, Kong F. Cheong, Nilesh W. GaikwadIn recent years several studies have attempted to understand the use of caffeinated beverages in North America before the coming of Europeans using absorbed residues. These studies have focused on the two key plant sources of caffeine in North America: Theobroma cacao (cacao) and Ilex vomitoria (yaupon holly). The authors initiated a study to explore the possibility that one or both plants were used at the Mississippian period (900–1600 CE) center of Etowah in northern Georgia. In the process, a series of problems with methodologies in use were revealed. Key among those were limitations on the methods used to identify ancient caffeinated beverage residues, distinguish them from modern contamination, and differentiate residues made by each plant. In this paper we explore what our data from the Etowah site reveal about methodologies currently in use and make suggestions for future studies of residues created by caffeinated beverages in North America.

Read more

Chemical analyses of Egyptian mummification balms and organic residues from storage jars dated from the Old Kingdom to the Copto-Byzantine period

Posted on July 8, 2017 by ARCAS

Publication date: September 2017Source:Journal of Archaeological Science, Volume 85 Author(s): Jeannette Łucejko, Jacques Connan, Sibilla Orsini, Erika Ribechini, Francesca ModugnoTwenty three samples of Egyptian organic materials, spanning from the Old Kingdom to the Copto-Byzantine Period, were investigated by gas chromatography-mass spectrometry. The sample set was comprised of ten balm samples from human mummies, three balms from shrews, and ten samples of residues scraped from jars and amphora from storehouses.This research program was undertaken with two main goals:Firstly to provide complementary data on the mummification balms from both humans and animals with an emphasis on the occurrence of bitumen in mummification mixtures.Secondly to explore whether the jar residues were mixtures that were used for mummification purposes or whether they were pure ingredients stored for various uses including ritual practices.The analysis highlighted that the most abundant constituents of the mummification balms were: fats or oils, waxes, conifer resin, pitch, mastic resin, castor oil, and bitumen. Balms from animal mummies were not found to be significantly different from the balms from human mummies. Residues from potsherds appeared to belong to two categories: pure products (fats and castor oil) and mixtures containing fats, Pinaceae resin and pitch, mastic resin, and castor oil, i.e. the constituents also identified in mummification balms. The mixtures were thus residues of preparations for ritual practices and embalming.This study demonstrates that bitumen is underestimated by the chemical approach currently applied in most archaeometric studies of Egyptian organic residues, which are better suited for the identification of lipids and resinous materials. We thus applied a specific analytical design, targeted at bitumen. Bitumen from the Dead Sea was conclusively identified using as reference materials for comparison, i.e. the present day bitumen from the Dead Sea floating blocks, as well as several bitumens from mummification balms and bitumen lumps unearthed from the archaeological site of Tell Yarmouth near Jerusalem in Israel.

Read more

Micromorphological indicators for degradation processes in archaeological bone from temperate European wetland sites

Posted on July 8, 2017 by ARCAS

Publication date: September 2017Source:Journal of Archaeological Science, Volume 85 Author(s): Hans Huisman, Kristin Ismail-Meyer, Barbara M. Sageidet, Ineke JoostenMicromorphological investigations of archaeological bones make it possible to study decay processes and the associated depositional environment in one go. A selection of micromorphological thin sections from soil samples from three wetland sites in Switzerland, The Netherlands and Norway that contained bone fragments were studied. The goal was to investigate the type and the timing of decay processes to better understand the taphonomy of bones in such sites. Using optical microscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), a range of biological decay processes and chemical/mineralogical transformations were observed. In two of the sites – Zug-Riedmatt in Switzerland and Hazendonk in The Netherlands – a relatively short exposure to adverse conditions must have occurred: Some of the bones from Zug-Riedmatt show localized collagen decay related to exposure to fresh ashes; others show cyanobacterial tunnelling related to submersion in shallow, clear water. In Hazendonk, bone fragments and fish scales apparently have first been exposed to bacterial decay related to putrefaction. Subsequently, alternations between wet and dry conditions resulted in the dissolution of some of the bone mineral and the formation of Ca, Fe(III) phosphates, probably mitridatite. Fungal decay caused extensive tunnelling of bone and fish scales as well as the secondary phosphates. These processes apparently ended when the bone-rich layer became permanently waterlogged and anoxic. In Stavanger, bone mineral is transformed into mitridatite and possibly other Ca Fe(III) phosphates. Indications that the redox conditions are variable at present suggest that these processes are still active.

Read more

Editorial Board

Posted on June 29, 2017 by ARCAS

Publication date: July 2017Source:Journal of Archaeological Science, Volume 83

Read more

Heat-induced alteration of glauconitic minerals in the Middle Stone Age levels of Blombos Cave, South Africa: Implications for evaluating site structure and burning events

Posted on June 27, 2017 by ARCAS

Publication date: Available online 27 June 2017Source:Journal of Archaeological Science Author(s): Magnus M. Haaland, David E. Friesem, Christopher E. Miller, Christopher S. HenshilwoodIn this paper we conduct geochemical and colourimetric measurements of glauconite grains in micromorphological thin sections from the Middle Stone Age site of Blombos Cave, South Africa, to investigate the formation, internal structure and reworking of heat-exposed cave deposits that are related to prehistoric burning events. Controlled heating experiments were first carried out on glauconite-rich loose sediments and block samples, both of which were collected from the Blombos Cave bedrock. The control samples were then subjected to Fourier transform infrared spectrometry (FTIR), microscopic Fourier transform infrared spectrometry (micro-FTIR) and petrographic-colourimetric analyses. The control experiment shows that glauconitic minerals undergo a gradual and systematic colour change when temperatures reach higher than c. 300–400 °C, primarily due to dehydration and iron oxidation. They also undergo clear structural changes when temperatures reach higher than c. 550 °C due to dehydroxylation and mineral transformation. By assessing the nature and degree of heat-induced optical and molecular alteration in glauconitic minerals, we demonstrate how glauconite grains in thin sections can be classified by the temperature to which they were exposed (20–400 °C, >400 °C, >600 °C and >800 °C). To assess the archaeological relevance of our controlled heating experiment, we applied this glauconite classification scheme to >200 grains found in three micromorphological thin sections of a Middle Stone Age (MSA) combustion feature. These grains were individually geo-referenced within the local coordinate system of Blombos Cave, through a thin-section-based GIS mapping procedure. With improved spatial control, we were able to study both the general distribution of non-altered and heat-altered glauconite grains in their original sedimentary context, as well as to calculate heat distribution models that cover the entire sampled section. This combined geo-chemical, optical and spatio-contextual approach provides insights into more elusive aspects of MSA site structure and burning events, such as heat intensity, burning frequency, temperature distribution, internal hearth structure and post-depositional reworking. The workflow we propose may easily be implemented and adapted to other archaeological contexts and to analogous sedimentary materials that show comparable heat-induced alteration patterns.

Read more

Materials analyses of pyrotechnological objects from LBA Tiryns, Greece, by means of Laser-Induced Breakdown Spectroscopy (LIBS): Results and a critical assessment of the method

Posted on June 23, 2017 by ARCAS

Publication date: July 2017Source:Journal of Archaeological Science, Volume 83 Author(s): Ann Brysbaert, Panayiotis Siozos, Melissa Vetters, Aggelos Philippidis, Demetrios AnglosLaser-Induced Breakdown Spectroscopy (LIBS) was used in the investigation of pyrotechnological materials (metal and ceramic items, glass-based objects, plaster-based materials) from several Late Bronze Age workshop and activity area contexts at Tiryns, Greece. The use of a portable instrument, which could be brought into the study place where all objects were housed, was crucial in order to establish the elemental content or verify the material composition of almost all materials analysed. In almost all cases, the LIBS analyses led to the preliminary identification of the materials investigated. In most cases, the results sufficed to confirm earlier research carried out or was in agreement with similar analyses published in the literature. The analyses demonstrate that the micro-invasive LIBS technique provides useful preliminary elemental characterization of most of the pyrotechnological materials while for some, additional work needs to be conducted for securing conclusive results. Essentially, the portability and compactness of the instrumentation enable its use in any workspace with a solid desk, light and electricity access which makes this technique very attractive for obtaining preliminary elementary results. While the technique remains limited by spot analyses it does open up an immense array of possibilities for routine characterization or speedy screening of different types of artefacts in any storage or museum context. These important methodological and scientific findings are considered prerequisite steps leading towards and aiding in responsible sampling strategies for further analyses.

Read more

Diet reconstructed from an analysis of plant microfossils in human dental calculus from the Bronze Age site of Shilinggang, southwestern China

Posted on June 23, 2017 by ARCAS

Publication date: July 2017Source:Journal of Archaeological Science, Volume 83 Author(s): Naimeng Zhang, Guanghui Dong, Xiaoyan Yang, Xinxin Zuo, Lihong Kang, Lele Ren, Honggao Liu, Hu Li, Rui Min, Xu Liu, Dongju Zhang, Fahu ChenThe extracted microfossils from the dental calculus of ancient teeth are a new form of archaeological evidence which can provide direct information on the plant diet of a population. Here, we present the results of analyses of starch grains and phytoliths trapped in the dental calculus of humans who occupied the Bronze Age site of Shilinggang (∼2500 cal yr BP) in Yunnan Province, southwestern China. The results demonstrate that the inhabitants consumed a wide range of plants, including rice, millet, and palms, together with other food plants which have not previously been detected in Yunnan. The discovery of various underground storage organs (USOs; tubers, roots, bulbs, and rhizomes) and acorns complements the application of conventional macrofossil and isotope studies to understand the diet of the Bronze Age human population of Yunnan. The wide variety of plant foods consumed suggests that the inhabitants adopted a broad-spectrum strategy of gathering food and cultivating crops in northwest Yunnan Province in the late Bronze Age at a time when agricultural societies were developed in the central plains of China.

Read more