Latest developments in rock art recording: towards an integral documentation of Levantine rock art sites combining 2D and 3D recording techniques

This paper presents a further step in the integral documentation of prehistoric rock art, combining 2D and 3D digital recording techniques. Image processing and digital enhancement techniques are an invaluable aid to obtain high quality and accurate 2D recordings, especially when working with faint motifs or complex superimpositions. But what constitutes a real breakthrough is the possibility of combining 2D digital tracings with metric 3D models, providing a whole set of metric outputs that improve our understanding of the motifs in their context and, at the same time, can be used to deliver accurate metric reproductions.     

Object-based landform delineation and classification from DEMs for archaeological predictive mapping

In this paper we report the results of an experiment with automated landform delineation and classification from digital elevation models (DEMs) using object-based image analysis (OBIA). Archaeologists rely on accurate and detailed geomorphological maps to predict and interpret the location of archaeological sites. However, they have been using high-resolution DEMs primarily for visual interpretation and expert-judgement classification of landform. OBIA can perform these classifications much faster and in a more objective fashion. The method was tested on a study area in the south east of the Netherlands. It is concluded that OBIA is a suitable technique for quick and objective delineation of landform, but needs an improved conceptual framework adapted to the local situation and archaeological questions to better identify and interpret the derived landform objects.     

Laser scanning for conservation and research of African cultural heritage sites: the case study of Wonderwerk Cave,South Africa

The ‘African Cultural Heritage and Landscape Database’ project, initiated and directed by the senior author and administered by Aluka (www.aluka.org), is aimed at the creation of a digital library of spatial and non-spatial materials relating to cultural heritage sites in Africa. The archaeological site of Wonderwerk Cave (South Africa) is one of the 19 sites documented to date using laser scanning, conventional survey, digital photogrammetry and 3D modelling. To date, it is one of the few archaeological caves worldwide to be fully scanned. This paper explores the different uses to which the spatial data derived from this cave have been, or will be, put – for historical and educational purposes, scientific research and site conservation and development.     

Comparing closed system, flow-through and fluid infiltration geochemical modelling: examples from K-alteration in the Ernest Henry Fe-oxide–Cu–Au system

Potassic alteration of rocks adjacent to, and within the Ernest Henry Fe‐oxide–Cu–Au deposit is used here as a test case to investigate fluid–rock interactions using various equilibrium dynamic geochemical modelling approaches available in the HCh code. Reaction of a simple K–Fe–(Na,Ca) brine (constrained by published fluid inclusion analysis) with an albite‐bearing felsic volcanic rock, resulted in predicted assemblages defined by (i) K‐feldspar–muscovite–magnetite, (ii) biotite–K‐feldspar–magnetite, (iii) biotite–quartz–albite and (iv) albite–biotite–actinolite–pyroxene with increasing rock buffering (decreasing log w/r). Models for isothermal–isobaric conditions (450°C and 2500 bars) were compared with models run over a T–P gradient (450 to 200°C and 2500 to 500 bars). Three principal equilibrium dynamic simulation methods have been used: (i) static closed system, where individual steps are independent of all others, (ii) flow‐through and flush, where a part of the result is passed as input further along the flow line, and (iii) fluid infiltration models that simulate fluid moving through a rock column. Each type is best suited to a specific geological fluid–rock scenario, with increasing complexity, computation requirements and approximation to different parts of the natural system. Static closed system models can be used to quickly ascertain the broad alteration assemblages related to changes in the water/rock ratio, while flow‐through models are better suited to simulating outflow of reacted fluid into fresh rock. The fluid infiltration model can be used to simulate spatially controlled fluid metasomatism of rock, and we show that, given assumptions of porosity relationships and spatial dimensions, this model is a first‐order approximation to full reactive transport, without requiring significant computational time. This work presents an overview of the current state of equilibrium dynamic modelling technology using the HCh code with a view to applying these techniques to predictive modelling in exploration for mineral deposits. Application to the Ernest Henry Fe‐oxide–Cu–Au deposit demonstrates that isothermal fluid–rock reaction can account for some of the alteration zonation around the deposit.     

Paleoethology as a tool for the development of archaeological models of land-use: the Crimean Middle Palaeolithic

The principal aim of our research is to capitalize on the close relationship between prehistoric hunters and prey to develop spatial models for the investigation of land-use patterns. Ideally, these models should be useful both as predictive tools for designing regional archaeological surveys, and as analytical tools for studying the distribution of known archaeological sites. Here, we build upon a basic G.I.S. model (including standard environmental variables such as slope, aspect and distance to water) adding a paleoethological variable in the form of range reconstructions for the regionally dominant, prehistoric human prey species: Equus hydruntinus.     

Estimation of Soil Erosion Using Field and Modelling Approaches in an Undisturbed Arnhem Land Catchment,Northern Territory,Australia

An assessment of slope erosion at Tin Camp Creek catchment, Arnhem Land, Northern Territory, Australia, was carried out using the fallout environmental radioisotope caesium‐137 (¹³⁷Cs) as an indicator of soil erosion status, two numerical models (SIBERIA and the Revised Universal Soil Loss Equation (RUSLE)) and erosion pins. This undisturbed drainage basin is situated in the seasonally wet‐dry tropics, with high energy storms and a mean annual rainfall of 1389 mm. Tin Camp Creek catchment is unaffected by European agriculture or pastoral activities, but often experiences fire during the dry season. Two transects were sampled for ¹³⁷Cs in 2002 and 2004, and two models were used to convert ¹³⁷Cs measurements into soil loss estimates. Two methods using the theoretical Profile Distribution Model (PDM) gave net soil redistribution rates between +2.72 and –22.19 t ha^?1 yr^?1 and +2.95 and –24.06 t ha^?1 yr^?1, respectively, while an Australian empirical model (AEM) for uncultivated soils produced estimates between +1.84 and –7.00 t ha^?1 yr^?1 (negative values indicate soil erosion, positive, deposition). The RUSLE gave estimated soil losses for the two transects of approximately 10 t ha^?1 yr^?1, while the SIBERIA model produced values between 0.5 and 2 t ha^?1 yr^?1 for the transects and between 3.5 and 11 t ha^?1 yr^?1 for the total catchment. Average net soil losses of 14 and 15 t ha^?1 yr^?1 for the total catchment and slopes, respectively, were measured by erosion pins. The soil losses in the catchment are similar to those for some other transects in the Northern Territory and the Kimberley region of Western Australia (measured by the ¹³⁷Cs AEM), even though these areas are affected by pastoral activities. This may be at least partly explained by erosion in Tin Camp Creek catchment during high intensity rainstorms at the commencement of the wet season, especially if the slopes have been affected by fire during the previous dry season.     

Suicide: the spatial and social components of despair in Britain 1980–2000

In this paper we show that, by accounting for the varying influence of just three area indicators of social isolation, it is possible to predict the number of deaths due to suicide and undetermined injuries (most of which are suicides) across a great many areas remarkably closely. The exceptions to this model suggest that in a few unique areas of the country other local, often historical and cultural or intrinsically geographical factors matter also. These findings of the general predictability of suicide matter because suicide is such a common cause of death, particularly for the young. Between 1 January 1981 and 31 December 2000, the underlying cause of the deaths of 130 000 people in Britain were recorded as being directly due to suicide, or in all probability being due to suicide. Collectively, these thousands of personal stories are brought together here to show how a pattern of despair in Britain over this period was spread across the country, affecting different places and different groups in society to differing extents over changing times. The changing geography of despair can be shown to be largely the product of changing economic, social and demographic geographies. This paper is concerned with determining the extent to which the stories of suicide in Britain were more than the sum of thousands of individual acts of misery and the extent to which they reflected the changing social structure of the country. Quantitative analysis is used to identify possible key trends with a more qualitative set of interpretations placed on the possible meanings of these findings. The paper concludes by speculating on how current social trends may influence the future map of the extremes of despair in Britain.     

Simulating archaeologists? Using agent-based modelling to improve battlefield excavations

The study of material culture generated by military engagements has created an emergent sub-discipline of archaeological studies centred on battlefields. This approach has developed a particular and sophisticated methodology that is able to deal with the fact that archaeologists will often not find either structures or a useful stratigraphical record on the site, as the material remains of the battle will basically be metallic objects carried by combatants. It is therefore rather complicated not only to test hypotheses about battle events based on archaeological data, but also to validate the methodology used. Here we propose the use of agent-based models to explore these issues in the case of eighteenth-century battlefield archaeology. The simulation is divided into four different steps. Firstly, a battle is simulated in order to generate realistic virtual archaeological remains left by an engagement between two armies of this era. We then simulate the loss of information that the passing of time produces in the battlefield. The third step involves simulating the archaeological survey, enabling us to explore different survey strategies and the impact on the interpretation of the event itself. Finally, we design a confidence index in order to compare the results of the different virtual excavations using spatial analysis and statistics. The results show that the methodology is fully functional in terms of understanding a battle, and it allows us to suggest new strategies to improve fieldwork and to develop new ways of exploring these particular archaeological sites. It is concluded that the described approach illustrates how simulation can be used to explore methodological issues of archaeological science.     

ARTIFICIAL ACCELEROGRAMS REPRESENTATIVE OF THE DAMAGE DISTRIBUTION ON A LOW-RISE SHEAR WALL

This study attempts to reproduce in an artificial way, at a given magnitude-distance couple, the statistical characteristics of damage caused by real accelerograms. The structure adopted is a low-rise shear wall, modelled as a nonlinear, one degree of freedom system with a degrading frequency as a function of a non-cumulative damage variable. Strong-motion records, contained in a large database, are characterised in terms of seismological and seismic parameters. Artificial accelerograms are generated from response spectra representative of real accelerograms belonging to different magnitude-distance zones. Although the mean damage is consistent, the low dispersion of damage caused by the artificial accelerograms with respect to that caused by the real accelerograms is highlighted. In order to reproduce the damage dispersion in addition to the mean damage, a generation method of representative artificial accelerograms is proposed. This method introduces the standard deviation drawn from attenuation relationships into a dispersion pre-process with respect to the regressed spectrum at a given magnitude-distance point. The method turns out to be capable of reproducing the statistical features of damage produced by real strong-motion records.     

Deep geothermal groundwater flow in the Seferihisar–Balçova area,Turkey: results from transient numerical simulations of coupled fluid flow and heat transport processes

The Seferihisar–Balçova Geothermal system (SBG) is characterized by complex temperature and hydrochemical anomalies. Previous geophysical and hydrochemical investigations suggest that hydrothermal convection in the faulted areas of the SBG and recharge flow from the Horst may be responsible for the observed patterns. A numerical model of coupled fluid flow and heat transport processes has been built in order to study the possible fluid dynamics of deep geothermal groundwater flow in the SBG. The results support the hypothesis derived from interpreted data. The simulated scenarios provide a better understanding of the geophysical conditions under which the different fluid dynamics develop. When recharge processes are weak, the convective patterns in the faults can expand to surrounding reservoir units or below the seafloor. These fault‐induced drag forces can cause natural seawater intrusion. In the Melange of the Seferihisar Horst, the regional flow is modified by buoyant‐driven flow focused in the series of vertical faults. As a result, the main groundwater divide can shift. Sealing caprocks prevent fault‐induced cells from being overwhelmed by vigorous regional flow. In this case, over‐pressured, blind geothermal reservoirs form below the caprocks. Transient results showed that the front of rising hot waters in faults is unstable: the tip of the hydrothermal plumes can split and lead to periodical temperature oscillations. This phenomenon known as Taylor–Saffman fingering has been described in mid‐ocean ridge hydrothermal systems. Our findings suggest that this type of thermal pulsing can also develop in active, faulted geothermal systems. To some extent, the role of an impervious fault core on the flow patterns has been investigated. Although it is not possible to reproduce basin‐scale transport processes, this first attempt to model deep groundwater geothermal flow in the SBG qualitatively supported the interpreted data and described the different fluid dynamics of the basin. Geofluids (2010) 10 , 388–405