Ancient lakes of the Sahara

As a result of climate change over the past 5000 years the Sahara changed from savannah to a desert landscape. The beds of ancient lakes are home to snail shells and the petrified roots of trees and shrubs. Examples of human occupation can also be seen in the form of fireplaces and discarded tools. Examination of the geological history of these sites can give a clearer picture of how the climate changed and how humans coped with these changes.

Rock art and social life - Revisiting the Neolithic transition in Mediterranean Iberia

This article revisits the Neolithic transition in Mediterranean Iberia taking into account an aspect usually neglected in the archaeological discourse: the rock art styles that emerged in this context. These distinct styles have been generally attributed to different populations, according to a historicist point of view that equates stylistic variability and ethnic identity. However, the recent recognition that they were developed by the same social group requires the formulation of an alternative explanation. My proposal is based on the exploration of the social context of production and consumption of the rock art, through the analysis of the patterns of location of the sites within the landscape and the definition of their archaeological context.

Experimental crop growing in Jordan to develop methodology for the identification of ancient crop irrigation

Crop irrigation has long been recognized as having been important for the evolution of social complexity in several parts of the world. Structural evidence for water management, as in the form of wells, ditches and dams, is often difficult to interpret and may be a poor indicator of past irrigation that may have had no need for such constructions. It would be of considerable value, therefore, to be able to infer past irrigation directly from archaeo-botanical remains, and especially the type of archaeo-botanical remains that are relatively abundant in the archaeological record, such as phytoliths. Building on the pioneering work of Rosen and Wiener (1994), this paper describes a crop-growing experiment designed to explore the impact of irrigation on the formation of phytoliths within cereals. If it can be shown that a systemic and consistent relationship exists between phytolith size, structure and the intensity of irrigation, and if various taphonomic and palaeoenvironmental processes can be controlled for, then the presence of past irrigation can feasibly be inferred from the phytoliths recovered from the archaeological record.

Stable isotope evidence for 1500 years of human diet at the city of York, UK

We present here the results of a large-scale diachronic palaeodietary (carbon and nitrogen isotopic measurements of bone collagen) study of humans and animals from a single site, the city of York (U.K.) dating from the Roman period to the early 19th century The human sample comprises 313 burials from the cemeteries of Trentholme Drive and Blossom Street (Roman), Belle Vue House (Anglo-Saxon), Fishergate (High and Later Medieval), and All Saints, Pavement (Later and Post-Medieval). In addition, 145 samples of mammal, fish and bird bone from the sites of Tanner Row and Fishergate were analyzed. The isotope data suggest dietary variation between all archaeological periods, although the most significant change was the introduction of significant quantities of marine foods in the Medieval periods. These are first evident in the diet of a small group of individuals from the High Medieval cemetery at Fishergate, although they were consumed almost universally in the following periods. The human isotope values are also remarkable due to unusually elevated delta N-15 ratios that are not sufficiently explained by the comparably small enrichment in C-13 that accompanies them. We discuss the possible reasons behind this and the archaeological significance of the data set.

Diet and diversity at later medieval Fishergate: The isotopic evidence

We present the results of stable carbon and nitrogen isotope analysis of bone collagen for 155 individuals buried at the Later Medieval (13th to early 16th century AD) Gilbertine priory of St. Andrew, Fishergate in the city of York (UK). The data show significant variation in the consumption of marine foods between males and females as well as between individuals buried in different areas of the priory. Specifically, individuals from the crossing of the church and the cloister garth had consumed significantly less marine protein than those from other locations. Isotope data for four individuals diagnosed with diffuse idiopathic skeletal hyperostosis (DISH) are consistent with a diet rich in animal protein. We also observe that isotopic signals of individuals with perimortem sharp force trauma are unusual in the context of the Fishergate dataset. We discuss possible explanations for these patterns and suggest that there may have been a specialist hospital or a local tradition of burying victims of violent conflict at the priory. The results demonstrate how the integration of archaeological, osteological, and isotopic data can provide novel information about Medieval burial and society.

A review of palaeoclimates and palaeoenvironments in the Levant and Eastern Mediterranean from 25,000 to 5000 years BP: setting the environmental background for the evolution of human civilisation

The southern Levant has a long history of human habitation and it has been previously suggested that climatic changes during the Late Pleistocene-Holocene stimulated changes in human behaviour and society. In order to evaluate such linkages, it is necessary to have a detailed understanding of the climate record. We have conducted an extensive and up-to-date review of terrestrial and marine climatic conditions in the Levant and Eastern Mediterranean during the last 25,000 years. We firstly present data from general circulation models (GCMs) simulating the climate for the last glacial maximum (LGM), and evaluate the output of the model by reference to geological climate proxy data. We consider the types of climate data available from different environments and proxies and then present the spatial climatic "picture" for key climatic events. This exercise suggests that the major Northern Hemisphere climatic fluctuations of the last 25,000 years are recorded in the Eastern Mediterranean and Levantine region. However, this review also highlights problems and inadequacies with the existing data. (c) 2006 Elsevier Ltd. All rights reserved.

Rapid characterisation of archaeological midden components using FT-IR spectroscopy, SEM-EDX and micro-XRD

Samples taken from middens at the Neolithic site of Catalhoyuk in Turkey have been analysed using IR spectroscopy backed up by powder XRD and SEM-EDX. Microcomponents studied include fossil hack-berries (providing evidence of ancient diet and seasonality), mineral nodules (providing evidence of post-depositional change) and phytoliths (mineralised plant cells, providing evidence of usage of plant species). Finely laminated ashy deposits have also been investigated allowing chemical and mineralogical variations to be explored. It is found that many layers which appear visually to be quite distinctive have, in fact, very similar mineralogy. (C) 2009 Elsevier B.V. All rights reserved.

Predictive vegetation mapping in the Mediterranean context: Considerations and methodological issues

The need to map vegetation communities over large areas for nature conservation and to predict the impact of environmental change on vegetation distributions, has stimulated the development of techniques for predictive vegetation mapping. Predictive vegetation studies start with the development of a model relating vegetation units and mapped physical data, followed by the application of that model to a geographic database and over a wide range of spatial scales. This field is particularly important for identifying sites for rare and endangered species and locations of high biodiversity such as many areas of the Mediterranean Basin. The potential of the approach is illustrated with a mapping exercise in the alti-meditterranean zone of Lefka Ori in Crete. The study established the nature of the relationship between vegetation communities and physical data including altitude, slope and geomorphology. In this way the knowledge of community distribution was improved enabling a GIS-based model capable of predicting community distribution to be constructed. The paper describes the development of the spatial model and the methodological problems of predictive mapping for monitoring Mediterranean ecosystems. The paper concludes with a discussion of the role of predictive vegetation mapping and other spatial techniques, such as fuzzy mapping and geostatistics, for improving our understanding of the dynamics of Mediterranean ecosystems and for practical management in a region that is under increasing pressure from human impact.