Time-Averaging Slows Down Rates of Change in the Archaeological Record

Measuring the pace of cultural change, and understanding its determinants is a fundamental goal of anthropological research. The archaeological record is the main source of information about the pace of cultural change, but it is an imperfect one, as taphonomic loss and mixing distort rate measurements. Here, I focus on the impact of time-averaging on rate measurements. Time-averaging arises when archaeological materials associated with activities and events that took place at different points in time are mixed into the same unit, whether because of depositional processes, disturbance factors, or because archaeologists lump together archaeological contexts when creating analytical units. I use analytical models to show how time-averaging can slow down the observed rates of change under two general modes of cultural change: random drift and directional change. I test this prediction using empirical rates of change from the archaeological record of North America. I show that empirical rates of change are indeed inversely correlated with the duration of time-averaging and provide a range estimate for this correlation.     

Looking for Ancient Fish Products Through Invisible Biomolecular Residues in the Roman Production Vats from the Atlantic Coast

As organic materials, fish and its derivative products are perishable and break down rapidly and ultimately disappear. Unless they include bones or scales, the only means of identifying them in the archaeological record is through the identification of the chemical constituents that are left behind after decomposition. Fish flesh mainly consists of proteins and lipids. Since these molecules are unstable they degrade irreversibly after death or discard, losing a significant part of the original chemical elements, consequently hampering or complicating their identification. In this paper, two main types of fish products are considered: raw, salted or cooked fish, and fermented fish-based products. In the first case, the degradation of the native markers results from chemical post-depositional degradation, and eventually thermal degradation during cooking. In the second case, the biochemical processes involve bacteria that cause the rapid decomposition of fish as part of the process of forming fish sauces, such as Roman garum. To detect and identify fish products we combined experimental archaeology and organic analyses. The identification of the degradation products of cholesterol appeared to provide a strong indicator for detecting the presence of fish sauces. Analysis of samples taken from fish-salting vats located along the Atlantic coast (Marsa, Baelo Claudia, Troia, Kerlaz, and Etel) with samples taken from actual experimental garum sauces made from mackerel (Scomber scombrus), sardines (Sardina pilchardus), and/or oysters (Ostreidae), revealed the presence of common markers of fermented fish-based products. The application of the analytical methodology described here to structures involved in ancient fish sauce manufacture and storage has enabled investigation of the production of the sauces by searching directly for the fish markers on the inner sides of the containers. For the first time the addition of molluscs and fruits in the fish product has been identified as part of the process of manufacturing garum.     

Identifying a technological style in the making of lime plasters at Teopancazco (Teotihuacan,México)

The aim of this article is to focus on the technology of archeological plasters at Teotihuacan (Central Mexico), from the Classic Period (200–650 A.D.), focusing in the study of Teopancazco, a neighborhood center in the city. Petrographic and chemical analyses by OM, SEM-EDS, and LA-ICP-MS were conducted to characterize samples from different constructive phases and sectors of the neighborhood center, to determine the provenance of the raw materials employed in the manufacturing (e.g., volcanic glass shards) and to assess whether a shift occurred in the manufacturing of plasters and in the procurement strategies of raw materials during the different phases. The results of the analyses show that almost no changes occurred in the making of the plaster during more than four centuries and allow us to consider the presence of a technological style in their manufacture, which is characterized by the making of plaster by mixing lime with volcanic glass shards, which in the case of Teopancazco were derived from the Altotonga (Veracruz) magmatic system. The data at our disposal suggest that this style was developed in Teopancazco and later introduced throughout the city of Teotihuacan in the Early Xolalpan phase (A.D. 350), although we still do not know whether the provenance of the raw materials is the same. The wide distribution of this technological tradition could be due to the technological properties of the materials and/or the influence of the intermediate elite who ruled over Teopancazco. The paper confirms that the study of material culture and technology sheds light on broader cultural aspects of ancient societies.     

Characterization of concrete from Roman buildings for public spectacles in <Emphasis Type="Italic">Emerita Augusta</Emphasis> (Mérida,Spain)

The aim of this work is to characterize the original concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required for a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (optical polarized microscopy and X-ray diffraction) and petrophysical (bulk and real density, open porosity to water and Hg, mechanical strength and ultrasonic velocity) analyses. With this work, it is possible to fill the gap that exists in this field and the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The results allowed us to determine the composition of the Roman concrete and to infer the provenance of the aggregates used in these monuments.     

A geometric morphometric relationship predicts stone flake shape and size variability

The archaeological record represents a window onto the complex relationship between stone artefact variance and hominin behaviour. Differences in the shapes and sizes of stone flakes—the most abundant remains of past behaviours for much of human evolutionary history—may be underpinned by variation in a range of different environmental and behavioural factors. Controlled flake production experiments have drawn inferences between flake platform preparation behaviours, which have thus far been approximated by linear measurements, and different aspects of overall stone flake variability (Dibble and Rezek J Archaeol Sci 36:1945–1954, 2009; Lin et al. Am Antiq 724–745, 2013; Magnani et al. J Archaeol Sci 46:37–49, 2014; Rezek et al. J Archaeol Sci 38:1346–1359, 2011). However, when the results are applied to archaeological assemblages, there remains a substantial amount of unexplained variability. It is unclear whether this disparity between explanatory models and archaeological data is a result of measurement error on certain key variables, whether traditional analyses are somehow a general limiting factor, or whether there are additional flake shape and size drivers that remain unaccounted for. To try and circumvent these issues, here, we describe a shape analysis approach to assessing stone flake variability including a newly developed three-dimensional geometric morphometric method (‘3DGM’). We use 3DGM to demonstrate that a relationship between platform and flake body governs flake shape and size variability. Contingently, we show that by using this 3DGM approach, we can use flake platform attributes to both (1) make fairly accurate stone flake size predictions and (2) make relatively detailed predictions of stone flake shape. Whether conscious or instinctive, an understanding of this geometric relationship would have been critical to past knappers effectively controlling the production of desired stone flakes. However, despite being able to holistically and accurately incorporate three-dimensional flake variance into our analyses, the behavioural drivers of this variance remain elusive.     

The Current Status of the Kenya Capsian

East Africa is home to a rich array of stone-tool traditions that span human prehistory. It is unsurprising, therefore, that the region attracted pioneer prehistorians in the early twentieth century, including L. S. B. Leakey, E. J. Wayland and T. P. O’Brien, who created the first cultural framework for East African prehistory during the 1930s. Although aspects of this framework remain relevant today, others have become misunderstood relics of an old classification system that hinders current research. This is particularly evident in the classification of a Later Stone Age (LSA) culture – the Kenya (East African) Aurignacian, later known as Kenya (East African) Capsian. Although this cultural entity was redressed during the 1970s and 1980s and redefined as the Eburran industry, there is still mystique surrounding the current status of the Kenya Capsian, its original scope and definition, the relationship with the Eburran and its position within a modern understanding of the East African LSA. This is largely due to paradigmatic shifts in researcher attitudes, leading to the use of the Eburran as a false proxy. It is necessary now to completely remove the term Kenya Capsian as an indication of similarity among the different LSA technologies. However, there also needs to be less emphasis on the importance of the Eburran and recognition that it is just one example of a multitude of diverse localised LSA industries. This will open the way for future research into the LSA and facilitate our greater understanding of recent prehistory in East Africa.     

A Context for Concealment: The Historical Archaeology of Folk Ritual and Superstition in Australia

Are there traditions of folk ritual practice in Australian historical contexts, and are they observable in the archaeological record? Studies from the US and UK have documented a range of practices suggesting the persistence of British and European traditions of folk magic well into the twentieth century and previous historical work has identified numerous examples of ritual concealments in Australian buildings. In examining over 4,500 Australian historical archaeological sources, however, we found very few examples of possible folk ritual practices. This raises the question of why such practices are not being captured by current archaeological recording methods. As counterpoint, a general model is constructed from US, UK and Australian work that raises intriguing possibilities for the situating of superstitious behavior in Australian historical archaeology, including the contexts in which people might be more prone to practise such behaviors and how they might be materially identifiable.     

A Place for Convicts: The Fremantle Lunatic Asylum,Western Australia and John Conolly’s “Ideal” Asylum

This article considers the mid to late nineteenth-century world of the Fremantle Lunatic Asylum, Western Australia. By examining the built environment of the asylum and the uses of spaces within its walls, it is possible to understand not just the experiences of the inmates, but to highlight attitudes towards the insane. The asylum was built under authority of the British Government, and later transferred to the Western Australian Government’s care. Reflecting on this volume’s theme of colonial institutions, this article will highlight the effects of center and periphery relationships on life within the asylum.     

Terrestrial and maritime taphonomy: differential effects on spatial distribution of a Late Pleistocene continental drowned faunal bone assemblage from the Pacific coast of Chile

Site GNL Quintero 1 (GNLQ1), located on the central coast of Chile, is the only documented Late Pleistocene drowned terrestrial site along the Pacific Coast of South America. Faunal evidence at the site is varied, and so far, remains of the following taxa have been found: extinct Camelidae, Cervidae, Equidae, Mylodontidae, Xenarthra, but also Myocastoridae, Canidae and Octodontidae. Both geological and paleoenvironmental data indicate that GNLQ1 developed in a floodplain or low-energy environment during the Last Glacial Maximum (LGM). Prior to the post-glacial rising of the sea level, the site would have been located several kilometres inland as the paleoshoreline was farther out on the continental shelf. In accordance with this background, the present study addresses the analysis of the spatial distribution of the bone deposits of GNLQ1 by considering both scenarios, the terrestrial phase related to the formation and modification of the fossil assemblage prior to the transgression, and the marine phase, subsequent to inundation. Results indicate modifications related to low-energy flow environment and carnivore activity dominated during the terrestrial phase and the action of marine organisms during the marine phase. Other taphonomic modifications are not easily attributable to either one or the other environmental context.     

Diet,social differentiation and cultural change in Roman Britain: new isotopic evidence from Gloucestershire

This study uses stable isotope analyses (δ¹³C and δ¹⁵N) of human bone collagen to reconstruct the diet of three Romano-British (first to early fifth century AD) populations from Gloucestershire in South West England. Gloucestershire was an important part of Roman Britain with two major administrative centres at Gloucester (Glevum) and Cirencester (Corinium) and numerous smaller settlements and farmsteads. To investigate potential dietary differences between the rural and urban populations of Roman Gloucestershire, we compared human bone collagen stable isotope values from 32 individuals from urban Gloucester with those of 46 individuals from two rural cemeteries at Horcott Quarry and Cotswold Community, respectively. Seven individuals from urban Gloucester were buried in a mass grave; all others were buried in single inhumations. Results show small but significant differences in stable isotope ratios between the urban and rural populations which indicate that the urban population might have consumed slightly more marine and/or freshwater resources than the people living in the rural communities. We interpret this difference as a direct reflection of Rome’s influence on Gloucester’s population and the town’s economic status. Subtle differences in stable isotope ratios were also observed at the site level, as burial practice does correlate with diet in some cases. Overall, the results from this study demonstrate that diet, as reconstructed through stable isotope analysis, is a very sensitive, if settlement-specific, indicator of social differentiation and culture change.