Magnetic imaging and electrical resistivity tomography studies in a Roman military installation found in Satala archaeological site,northeastern Anatolia,Turkey

Satala is one of the last great military centers in the Roman East available for archaeological and historical investigations. This archaeological site is situated on the crossing of two singularly important routes in North-East Asia Minor. Only little archaeological fieldwork in and around Satala has so far been carried out, thus delimiting our knowledge of the site and its role within the Roman military structure of the East. In order to provide further data on the site, we carried out geophysical surveys including the application of magnetic and electrical resistivity techniques in an area north of the Sadak village. The geophysical surveys within this area (supposedly part of the Roman military camp) proceeded in two stages. The first stage saw magnetic gradiometer imaging studies being carried out on 2.1 ha, measured by a Geoscan FM-36 fluxgate gradiometer by using 0.5 × 1 m grid intervals. For the second stage a different geophysical technique was used—resistivity tomography. Resistivity data were collected using a number of combined 2D resistivity pseudosections in the eastern part of the area which contained very regular magnetic anomalies. The 3D data were obtained by the combination of all survey lines collected from 2D data sets, and thereafter the arranged data were processed by using the 3D robust inversion modified from the smoothness-constrained algorithm. Electrical resistivity tomography investigations revealed that the buried archaeological structures might be located near the surface, except for some structures found in the middle of the studied area. The archaeological structures were furthermore determined by realistic model sections and volumetric representations. Magnetic imaging and electrical resistivity tomography surveys show that the combined usage of these techniques advances the understanding of archaeological structures beneath the surface.     

The role of time-lapse bathymetric surveys in assessing morphological change at shipwreck sites

Data from time-lapse single-beam and multi-beam bathymetric surveys are used to assess the rate and scale of morphological change at shipwreck sites caused by anthropogenic forcing. The technique is illustrated by characterizing changes in wreck site morphology over two sites located on the east coast of Ireland – the Drogheda Boat site on the River Boyne and the Arklow Bank site in the Irish Sea. Results indicate that repeated bathymetric surveys accurately and rapidly capture morphological change, with time-lapse accretion–erosion models indicating possible erosion rates of up to 0.04 m per day and accretion rates of 0.36 m per day at dynamic riverine and marine sites in response to external triggers. These data are valuable in understanding site formation processes at fully submerged archaeological sites and in the derivation of high-resolution site formation models.     

The use of magnetometry and pole-dipole resistivity for locating Nabataean Hawar archeological site in the SW-Jordan

This paper is focused on the joint use of magnetometry and pole-dipole electrical resistivity geophysical methods for assessing their capability in the detection of a prehistoric site in the southwestern Jordan. The survey area, Auara, was built in the first century BC during the Nabataean time and is located in a very arid environment framed on the east and north by white sandstone hills. In order to test this site, a number of magnetic stations and two pole-dipole resistivity traverses were carried out in the investigated area. Magnetic data were taken with one sensor at height of 0.8 m along survey lines spaced 1 m apart. Resistivity measurements were carried out utilizing the pole-dipole array along two profiles. A total of 32 geoelectrical stations spaced 2 m were made along the two profiles. Magnetic method found structure with contrasting physical properties to those of the surrounding material. The archeological interpretation of such structure is in terms of rectangular cistern (pool) with dimensions 26 × 16 m. A probable location of two buried walls spaced 16 m are indicated by low resistivity values.     

Stable isotopes and diet at Ancient Kerma,Upper Nubia (Sudan)

Carbon and nitrogen stable isotope values were measured from bone collagen extracted from archaeological Nubian human (n = 54) and faunal (n = 61) populations from the site of Kerma, Sudan. Collagen suitable for isotopic analysis was extracted from 22 faunal and 48 human samples from the Eastern cemetery site, dated to the Middle Kerma (c. 2050–1750 BC) and Classic Kerma (c. 1750–1500 BC) periods respectively. The isotopic data indicate that the human dietary regimen included a mix of C₃ and C₄ plant-derived components, with a larger C₄ component than previously reported in archaeological Egyptian Nile Valley populations. Elevated δ¹⁵N values are attributed to consumption of dietary resources from a ¹⁵N-enriched terrestrial ecosystem. The faunal isotope data also indicate the consumption of C₃ and C₄ plants. The large range of δ¹³C values measured in both the human and faunal samples supports previous work suggesting that a significant portion of the populations buried at Kerma may have originated elsewhere, further confirming the Nile Valley as a major corridor for population movement in the region.     

Integrated geophysical surveys at the archaeological site of Tindari (Sicily,Italy)

The results of geophysical survey carried out at the archaeological site of Tindari, located 70 km west-north-west of Messina (Sicily, Italy), are presented and discussed. The site is one of the most important archaeological sites, about 90 ha large, on the north-eastern side of Sicily and it was one of the last Greek settlements in Sicily. Keeping in mind the vastness of the site, according to the archaeologists an area, of about 1200 m² was selected, for a geophysical survey. Electrical resistivity tomography (ERT), including induced polarization (IP) measurements, and seismic refraction tomography were applied in the course of geophysical exploration in the area. The objective of this preliminary geophysical investigation was to verify the effectiveness of the technique for a spatial definition of the buried archaeological structures (mostly walls, columns, etc.) to determine their characteristics and to study the presence of collapsed columns within the zone of archaeological interest, in view of their application in the rest of the site, that, for obvious reasons, could not be entirely excavated in brief times. The geophysical data, visualized in 3D space, revealed a distribution of low-contrast shallow anomalies that indicate the presence of different types of buried structures in the surveyed area. Also, the probable accumulations of collapsed columns could be determined. These results confirm the hypothesis of a large northern extension of the archaeological site and provide useful information to design a more efficient excavation plan.     

Three-dimensional image of seismic refraction tomography and electrical resistivity tomography survey in the castle of Occhiolà (Sicily,Italy)

A geophysical survey was carried out at the ruins of Occhiolà Castle (Sicily, Italy), a medieval village located at the north-western part of a hill named “Terravecchia” at 491 m asl. In order to map the archaeological structures (such as walls and burrows), Electrical resistivity tomography (ERT) and seismic-refraction tomography methods were used. The resistivity variations are known to correlate quite well with the lithology, thus providing important information for identifying the buried archaeological remains. On the other hand, seismic velocity variations provide information about the geometrical features of the remains. The two geophysical methods are used in an enjoined way to better aid the interpretation and evaluate the significance and reliability of the results obtained with each single method. The electrical and seismic data are displayed in three dimensions by using the iso-resistivity and iso-velocity surfaces, respectively. This allows us to effectively define the location of the anomalies present in the single electrical and seismic sections. The results obtained in the survey highlight the presence of structures of regular shape, probably due to features of archaeological interest.     

Holocene paleoshorelines,water levels and submerged prehistoric site potential of Rice Lake (Ontario,Canada)

Rice Lake, located in the eastern Great Lakes of North America, has a high density of prehistoric (11–0.5 ka BP) terrestrial archaeological sites. It has been speculated that a large number of sites are submerged on the lakebed, as lake levels have risen >9 m since the arrival of Early Paleoindian peoples (∼11 ka BP). In order to better understand the submerged landscape and its archaeological potential, a detailed bathymetric survey and sediment-coring program was conducted across a 30-km² area of northeastern Rice Lake. Changes in Holocene water levels and shoreline positions were reconstructed by integrating core data with a digital elevation and bathymetric model (DEBM) that accounted for differential isostatic uplift and basin sedimentation. The DEBM was used to generate a series of maps showing changes in the lake paleobathmetry and paleogeography and areas of prehistoric archaeological potential.     

Process-based models for port evolution and wreck site formation at Mombasa,Kenya

Mombasa Island, settled for almost 2000 years, played a central role in the development of the central seaboard of East Africa, emerging by the 16th century as a centre of sustained port dominance. Marine geoarchaeological surveys were conducted in Mombasa Harbour in 2001 (i) to quantify the nature and extent of the submerged archaeological resource, (ii) to investigate site formation and preservation potential of historic shipwrecks, and (iii) to explore the natural evolution of the Old Port and adjacent basins in the context of hydrodynamic and sedimentary processes. Backscatter and single-beam echo-sounder data were acquired, interpreted and diver-truthed using surface-demand and SCUBA systems. It is proposed that sustained scour processes, resultant from the interaction of ebb and flood tidal currents with bedrock ridges, control the bathymetric evolution of Mombasa Harbour, negating requirement for mechanical dredging. The submerged archaeological resource in the area comprises fish traps and shipwrecks. Physical processes govern shipwreck site formation, with scour and bed-migration dominant, ultimately leading to structural instability and site degradation. The wreck of Santo António de Tanná (1697) has been subject to gravitational collapse and mass down-slope movement of material, concentrating wreck structure and material along the portside stern third of the vessel.     

Cesium magnetometer surveys at a Pithouse Site near Silver City,New Mexico

The La Gila Encantada Site is located on an isolated ridge top north of Silver City, New Mexico in an area defined culturally as the Mimbres Mogollon region. The 180 m × 80 m (14400 m²) sized site was originally recorded as a dense scatter of ceramics, lithics, and ground stone along with a number of surface depressions that appear to represent pithouses. Cesium magnetometer surveys were conducted to identify hearths, pithouse boundaries, and activity areas outside of pithouses in support of archaeological investigations, and to test this instrument's ability to image these features. This paper presents a characterization of the magnetic signature of a pithouse as a magnetic high in the center caused by the central hearth, low magnetic variability along the floor of the house, and then increased magnetic variability at the pithouse boundary. This characterization was successfully confirmed for three pithouses using cesium magnetometery and archaeological excavation.     

Potential of satellite based sensors for studying distribution of archaeological sites along palaeo channels: Harappan sites a case study

A large number of remote sensing based studies have shown evidence of a prominent river system, which has become buried under sand cover of Thar Desert sometime during late Holocene. This major river has been identified as Sarasvati, a legendary river mentioned in ancient Indian texts. This region is rich with archaeological sites of Harappan civilization (2500–500 BC). The present study has utilised digital image processing and enhancements techniques on multisensor satellite data followed by field investigations to reconfirm known traces and detect hitherto unknown traces of palaeochannels of Sarasvati river through parts of Indus alluvial plain in Thar desert. Potentials of IRS-P4 OCM (Primarily an Ocean Color Sensor, with eight narrow spectral channels, high radiometric resolution of 12 bits and large swath of 1420 m) could be exploited for the first time to detect hitherto unknown traces of palaeochannels of Sarasvati river through sand dune topography of Thar desert in parts of Western Rajasthan in India and adjoining parts of Pakistan by applying Principal Component Analysis technique. Pattern of palaochannels indicate westward migration of the Sarasvati river in parts of Indus alluvial plain. Database of more than 1000 archaeological sites compiled from various published sources, prepared in GIS environment could be utilised to understand their relationship with identified courses of the Sarasvati palaeochannels. Through this study it was found that there is a large spread of Mature Harappan (2200–1700 BC) sites along the palaeochannel of the Sarasvati and its tributaries in north-west India, but late Harappan (1700–1500 BC) sites are limited to further west in adjoining regions of Pakistan indicating that the shift of cluster of settlements have followed the pattern of river migration towards west. Digital terrain modelling by superimposing archaeological sites on SRTM DEM along with draped satellite data (Resourcesat-1 AWiFS and IRS-1D LISS-III) has helped in identifying geomorphological guides for archaeological investigations such as presence of relict natural levees seen as raised mounds and coincidence of known archaeological sites over them. It is suggested that other relict natural levees or raised mounds adjoining the identified palaochannel courses may be taken up for further archaeological exploration.     

Using Multibeam Echo‐Sounder Data to Identify Shipwreck Sites: archaeological assessment of the Joint Irish Bathymetric Survey data

This paper describes Phase 1 of the project ‘Archaeological Applications of the Joint Irish Bathymetric Survey (JIBS) Data’, analysing bathymetric and backscatter data derived from multibeam surveys off the north coast of Ireland. In particular, the usability of the data for shipwreck detection, identification and site characterization is explored. In Phase 1, the data was screened for anomalous sea‐bed features, which were subsequently described, catalogued and categorized according to their archaeological potential and cross‐referenced against existing records. A planned second phase of this project will examine each anomaly in greater detail together with the local and regional hydrodynamic conditions. © 2010 The Authors     

Quantifying tomb geometries in resistivity images using watershed algorithms

Quantifying the geometries (defined here as width, height and depth of burial) of archeological structures within resistivity models produced as a result of the regularization constraints used in most inversion algorithms is difficult, especially when structures are closely spaced. Here we apply the watershed by simulated immersion method of boundary detection to smooth 2D resistivity images generated for synthetic and field data over 3D targets. The synthetic studies include a single cavity model, a model for two widely spaced cavities (spacing ? unit electrode spacing) and a model for two closely spaced cavities (spacing < unit electrode spacing). We also examine a single-cavity model where a relatively resistive overburden, common at archaeological sites in Egypt, is included. In the case of the single cavity models, the maximum error for any geometries are 18% for the model without the resistive overburden and 10% for the model where the overburden is included, whereas it increases to 24% for the widely spaced model and 40% for the closely spaced model. Despite, the higher errors in the closely spaced cavity model, application of the algorithm confirms the presence of two features, which is not ascertainable from the smooth resistivity images. Boundaries detected with the watershed algorithm are subsequently used to define a disconnect in the regularization, resulting in a markedly improved estimate of the resistivity structure (particularly for the closely spaced cavity model) in a second inversion step using the model obtained from the smoothness constraint inversion as the starting model. This revised resistivity model also results in a lower root-mean-square (rms) misfit between measured and theoretical data, and between synthetic and inverted models. We demonstrate how the method can be applied on images from the archaeological site at Qurnet Murai, Luxor City Egypt.     

Going underground: experimental carbonization of fruiting structures under hearths

We show that carbonized fruits and seeds recovered from Middle Stone Age deposits in rock shelters are likely to have been carbonized as part of post-depositional processes. We buried indigenous South African fruits, nuts and seeds at pre-determined depths and distances from the centers of experimental fires. The cold ashes of the hearths and the sand surrounding them were subsequently excavated, using standard archaeological techniques and dry-screening. The fruiting structures from the oxidizing part of the fire were burnt to ashes, whereas those buried in sand under anoxic conditions survived in varying forms. Those buried 5 cm below the center of the fire were carbonized; those buried 10 cm below the center of the fire were dehydrated; and those 5 cm and 10 cm below the surface at the outer edge of the fire were unaffected. Size, moisture or oil content of the original fruit or seed did not appear to influence whether or not carbonization took place. Temperatures recorded 5 cm below the experimental fires suggest that the carbonization occurred at or before a maximum temperature of 328 °C, and also at lower maximum temperatures (152 °C) that were maintained for long periods. Even when the quantities of a particular wood are controlled, open fires may produce variable underground temperatures and the temperatures below ancient hearths would have been equally variable. We suggest that Cyperaceae (sedge) nutlets, the most numerous fruiting structures in the Sibudu Middle Stone Age archaeobotanical assemblage, occur in the shelter as a result of human activity, subsequent burial, and accidental carbonization when hearths were built directly above the buried nutlets.     

Plant exploitation and ethnopalynological evidence from the Wadi Teshuinat area (Tadrart Acacus,Libyan Sahara)

Pollen analyses of 13 archaeological sites in the Wadi Teshuinat area, in southwestern Fezzan, Libya, were synthesised to explore the potential contribution of palynological investigation to archaeological research in this area. During the Holocene, the sites were occupied by pre-Pastoral (hunter–gatherers) and Pastoral (pastoralists) cultures. Different pollen stratigraphies and floras characterised the diverse sites and the relevant cultural phases. Pollen data were reported by discussing the sites separately, and by combining them to interpret the regional data set. Emphasis was made on the anthropogenic pollen indicators and grasses, including large grass pollen grains (>40 μm), which were considered evidence of plant transport into the site. These were ethnobotanical markers, human-made evidence of plant harvesting by hunter–gatherers, or of animal breeding by pastoralists. The disappearance of some wild cereals was also observed, consistent with increasing climate dryness and land exploitation. Macroremains were used as a parallel tool to better understand plant exploitation in the region.     

Morphological,chemical and physical changes during charcoalification of wood and its relevance to archaeological contexts

Wood exposed to a heat source can be transformed into charcoal if subject to conditions of carbonisation (in the absence of air) or charring (in restricted air). Charcoal recovered from archaeological sites can yield fundamental information to our understanding of human economic and cultural development over time and (ecological) setting. This work describes the morphological (anatomy, degree of shrinkage), physical (reflectance) and chemical (elemental, molecular composition) properties of charcoal in relation to heat source and wood variables. In this study charcoal and charcoal fuel were experimentally produced whereby temperature (160–1200 °C), time of exposure (2–1440 min), heating rate (high and low) and wood type (angiosperm and conifer) were varied. The results show that charcoal, often described as an inert, black material, has different chemical and physical properties in relation to the investigated variables. By using these different properties it is possible to distinguish between the different types of fires (domestic and industrial) exploited by humans in the past. Morphological analyses and reflectance measurements are effective tools for this purpose and can be used in wood exposed to temperatures of 300 °C and above—temperatures which are relevant to archaeological research. Angiosperm and conifer wood react in different ways when exposed to heat and thus the taxonomic identity of archaeological material needs to be known. Chemical analyses can be used for wood exposed to temperatures below 400 °C whereas elemental analyses of the carbon content can be used for wood exposed to temperatures up to a maximum of 650 °C.     

Monuments on a migrating Nile

River courses migrate, but many Egyptologists plot the present-day River Nile on maps of the valley in archaeological times. This may have misled interpretations of ancient monuments and settlements. We show a river migrating rapidly on historical timescales in the Luxor region, sweeping > 5 km across the valley at rates on the order of 2–3 km per 1000 years. Satellite elevation data (SRTM), processed by a novel method, and Landsat imagery are used to trace ancient river levees and extend trends present in 200 years of archive maps thousands of years into the past. This supplements observations by Ptolemy (121–141 AD) and places local geo-archaeological studies in a wider spatial and temporal context. Satellite data are demonstrated to be a relatively quick and easy constraint upon ancient river courses, and a basis for investigations along the Egyptian Nile, even in logistically inaccessible regions.     

Shallow geophysical survey at the archaeological site of San Miguel Tocuila,Basin of Mexico

A combined near surface geophysical survey conducted in San Miguel Tocuila show that geophysical methods offer the possibility to characterize and reconstruct the geometry of subsurface structures without destroying the deposits, providing a way to find solutions to the questions of archaeological or engineering significance. The survey consisted of the application magnetometry, seismic refraction tomography (SRT) and ground penetrating radar (GPR) within a depth range of 10 m. Before Spanier conquest San Miguel Tocuila was a very prominent suburb of the main Aztec ceremonial complex located on the eastern margin of Lake Texcoco, central Mexico, where several mounds known as Tlateles in Nahuatl language have been identified. Nowadays, the rapid expansion of Mexico City's metropolitan area within the last four decades has strongly influenced Tocuila's environment and has compromised several of its archaeological and ancient human settlements. This study shows how the high resolution imagining of non-invasive geophysical methodologies in addition with surface archaeological studies [Parsons, J.R., 1971. Prehistoric Settlement Patterns in the Texcoco Region, Mexico. Memoirs of the Museum of Anthropology, University of Michigan, Number 3] provide different kinds of information that characterize the subsoil and a buried structure. Based on the history of the ancient settlements in the zone and considering the characteristics of shape and height of the structure, we interpreted that the subsurface images obtained depict a buried Tlatel which corresponds to a ceremonial–civic center of Late Aztec times.     

New radiometric ages for the Early Upper Palaeolithic type locality of Brno-Bohunice (Czech Republic): comparison of OSL,IRSL, TL and C dating results

New radiometric data are reported from the recent excavation of the type locality of the Early Upper Palaeolithic entity of the Bohunician. Recently obtained radiocarbon (¹⁴C) data on charcoal are compared with new Optically Stimulated Luminescence (OSL) dating of sediment. OSL ages were determined on sediment from the archaeological occupation at Brno-Bohunice, as well as from the over- and underlying loessic sediments. Multiple techniques were applied, which all gave congruent results. While a dual protocol (post IR-OSL) failed the quality criteria tests, ages were obtained by Multiple-Aliquot-Additive-Dose (MAAD) on polymineral material and Single-Aliquot-Regeneration (SAR) on fine grain quartz extract as well as on polymineral material. Fading tests show significant loss of Infrared Stimulated Luminescence (IRSL) after storage for 3 and 12 months for one sample, but little or no fading for others. The resulting (uncorrected) age estimates are smaller than those on quartz by OSL methods. The latter are considered to be more reliable estimates of the sedimentation age of these deposits. The measured OSL doses do not show a simple distribution and the lowest 5% was used for age calculation to represent the most likely sedimentation age. The quartz from the loess overlying the archaeological layer is OSL dated to 30.9 ± 3.1 ka, while the sediment for the paleosol which contains the archaeological layer gave an age of 58.7 ± 5.8 ka. The attribution of this paleosol to the Hengelo interstadial is therefore questionable. However, if the Hengelo interstadial is correlated with the Dansgaard/Oeschger (D/O) event 12, statistical agreement within 2-σ is achieved. The OSL result for the archaeological layer is in accordance with a weighted average TL date on heated flint artifacts of 48.2 ± 1.9 ka from this layer as well as calibrated radiocarbon data (CalPal Hulu 2007) from nearby locations. However, radiocarbon data on charcoal samples obtained during excavation at Brno-Bohunice 2002 provide age estimates between 30 and 40 ka ¹⁴C-years, which translate to approximately (33) 35–44 ka on the calendric time scale according to the Hulu 2007 model. For the underlying loess a depositional age of 104.3 ± 10.6 ka was obtained by OSL. The presented OSL ages indicate that a simple correlation of soil sequences between sites within a region has to be verified by chronometric dating.     

Effects of site lithology on geochemical signatures of human occupation in archaeological house plans in the Netherlands

This study presents the application of multi-element soil analyses (X-ray fluorescence spectroscopy and inductively coupled plasma optical emission spectroscopy of 1 M HCl extracts) to grid samples from 3 archaeological house plans embedded in sandy clays, clays and sands to assess effects of site lithology on geochemical signatures of human occupation.