Showing papers in "Archaeological Prospection in 2002"

Georadar in the Roman civil town Carnuntum, Austria: an approach for archaeological interpretation of GPR data

Abstract: The case study presented is a prime example of integrated geophysical–archaeological prospection. The aerial photographs available are complemented by non-destructive geomagnetic and geoelectric surveys with a reading distance of 0.5 m or less. To gain depth information and provide higher resolution, ground-penetrating radar (GPR) data are integrated. The GPR data were collected in a 0.5 × 0.05 m raster and visualized as black-and-white time or depth slices. The developments presented allow us to incorporate GPR into the standardized interpretation process of archaeological prospection based on a geographical information system (Grs). Using GPR and all the other prospection data available as a basis, a detailed three-dimensional interpretation model of the monument detected, the southern part of the forum of the civil town of Roman Carnuntum, is created. Copyright © 2002 John Wiley & Sons, Ltd.

Satellite remote sensing and archaeology: a comparative study of satellite imagery of the environs of Figsbury Ring, Wiltshire

Abstract: The abilities of three satellite remote sensed image products (low spatial resolution LANDSAT Thematic Mapper (TM); medium resolution SPOT Panchromatic; high resolution KVR-1000) to detect archaeological features in the environs of the Iron Age hillfort at Figsbury Ring, Wiltshire, have been evaluated. Given prior knowledge of their locations, relatively large features together and those possessing a strong linear nature could be detected on the LANDSAT TM multispectral and SPOT Panchromatic image products. Near-infrared TM imagery showed promise for the detection of smaller features as a result of differences in vegetation cover, but was constrained by its low spatial resolution. High resolution Russian KVR-1000 imagery was found to be capable of detecting both upstanding and ploughed-out archaeological features without the need for prior knowledge of ground truth. It is concluded that satellite imagery, although not a substitute for conventional aerial photography, represents a complementary source of information when prospecting for archaeological features. In a regional context, low resolution multispectral imagery can be used for the prospection for areas of high archaeological potential through the use of image processing and modelling techniques and, together with medium resolution imagery can be used to prepare base maps of regions for which up to date mapping is not available. High-resolution imagery, together with conventional aerial photographs, can be used subsequently to detect and map archaeological features. Copyright © 2002 John Wiley & Sons, Ltd.

Ground-penetrating Radar Survey to Map the Location of Buried Structures under Two Churches

Abstract: The range of ground-penetrating-radar (GPR) applications is very wide and diverse. Ground-penetrating radar provides high-resolution continuous profiles, and it has been used in various fields such as environmental, geology, geotechnical engineering, archaeology, etc. Two surveys with GPR were undertaken inside two churches (the church of St Oronzo and the church of Immacolata) at Novoli village, located a few kilometres northwest of Lecce (Italy). The purpose of the two surveys was to obtain information about the existence of ancient structures beneath the two churches. No document or writing exists to confirm the presence of structures under the two churches. However, there are several oral testimonies handed down over the centuries that suggest the presence of these ancient structures. Both surveys were carried out using a GSSI Sir System2, incorporating 500 MHz centre frequency antenna. The GPR time slices were constructed from closely spaced parallel profiles. The time slices, computed from averaging radar reflections over vertical time windows several nanoseconds thick, are used to map subsoil features associated with the structures, probably of anthropogenic origin. To facilitate the interpretation of the results, a three-dimensional image was constructed using closely spaced parallel profiles, which are linearly interpolated. Copyright © 2002 John Wiley & Sons, Ltd.

Investigation of a Bronze Age plankway by spectral induced polarization

Abstract: The induced polarization (IP) method was developed originally for ore exploration. The transition from electronic to electrolytic conduction causes strong polarization effects in ores. However, other porous materials also exhibit polarization effects. They are caused by electrochemical processes at the internal interface between the pore fluid and the mineral grains. Although these effects are one to two orders smaller in size, modern IP equipment is able to resolve these phenomena. Spectral induced polarization (SIP) investigates the polarization effect in a wide frequency range. As a SIP measurement has an identical setup to conventional resistivity survey, a multichannel geoelectrical instrument (SIP-256) was developed that is able to measure both apparent resistivity and the polarization effect using a multi-electrode array. The Federsee bog near Lake Konstanz with its optimal preservation conditions is of international importance for archaeology. Pile dwelling settlements dating back to the eneolithicum have been revealed. Wood samples of a Bronze Age plankway (1500–1400 BC) were collected and investigated. The astonishing result of the laboratory measurements was that the samples showed a remarkable polarization effect in the classic frequency range of IP. Wood therefore can be regarded as a polarizable material. As a consequence a SIP survey was performed in order to investigate the plankway. The SIP survey was carried out in a frequency range from 1 to 60 Hz, where the maximum polarization effect in the laboratory was observed. Two profiles were measured, one parallel and one perpendicular to the plankway. In contrast to the result of the resistivity measurement, the plankway could be identified by weakly increased polarization effects. Copyright © 2002 John Wiley & Sons, Ltd.

Mapping the roots of agriculture in southern Arabia: the application of satellite remote sensing, global positioning system and geographic information system technologies

Abstract: Satellite remote sensing, global positioning system (GPS) and geographical information system (GIS) technologies form a powerful methodological and analytical triad for archaeological research, particularly in remote regions where few large-scale maps are available. This paper outlines the application of these technologies as a component of the Roots of Agriculture in Southern Arabia (RASA) research project and provides a review for archaeologists interested in potential applications, particularly in arid and semi-arid environments. We used LANDSAT satellite imagery and GPS data to construct a GIS and provide a foundation for the management and analysis of archaeological, geomorphological and palaeoecological evidence of middle Holocene environmental conditions and human land-use in the remote highlands of southern Yemen. Using both supervized and unsupervized multispectral landscape classification procedures we categorized the landscape into seven classes based on landform and sedimentary cover characteristics. The resulting GIS helps us evaluate the relationship between landscape characteristics, site location, site preservation, and investigate associations with sociocultural and environmental variables. Copyright © 2002 John Wiley & Sons, Ltd.

Soil and susceptibility: aspects of thermally induced magnetism within the dynamic pedological system

Abstract: Magnetic surveys now form part of the panoply of techniques used in archaeological investigations. Techniques such as magnetic gradiometry depend on bodies of soil developing enhanced magnetic susceptibilities. This enhancement, whether via heating or by ongoing pedological processes, is due to reduction and oxidation cycles within the soil. The salient point of this paper is that, the soil is a dynamic medium in which iron is subject to ongoing soil process. Several case studies are examined to illustrate these points. Copyright © 2002 John Wiley & Sons, Ltd.

Selected radar images of man-made underground galleries

Abstract: Ground-penetrating radar (GPR), as a high-resolution geophysical prospecting method, has proved to be a very useful tool in archaeological site investigations, especially in the detection and identification of tunnels and galleries. This work shows seven selected profiles collected at four different archaeological sites in Spain and Mexico, with a wide variety of targets, not only in terms of their size (from 1 × 1 m to 3 × 4 m) but also in their depth (from 0.5 to 7 m). In all, 14 galleries and/or tunnels were detected. The approach to these studies was organized in two ways: firstly the presence of a known subsoil was used to compare the response of different antennae looking for these kinds of targets; secondly, GPR was used to find unknown historical galleries before any excavation took place. The equipment used in these studies were the SIR-8, with 120 and 500 MHz monostatic antennae, and PulseEkko IV, with 100 MHz bistatic antennae. Copyright © 2002 John Wiley & Sons, Ltd.

A case study in the analysis of patterns of aerial reconnaissance in a lowland area of southwest Scotland

Abstract: Analysis of aspects of an ongoing programme of aerial reconnaissance, looking for archaeological sites revealed as cropmarks, in a lowland part of southwest Scotland has identified biases in the survey. Areas of known potential tend to be targeted at the expense of less rewarding ground, contributing to an imbalance in the known distributions of sites created by regional variations in land-use patterns. A relationship between areas with a high density of sites, in a year of exceptional cropmark formation, and a high incidence of sites that have not been adequately recorded also can be identified. The ongoing assessment of survey data is a key factor in offsetting the impact of such biases in the longer term, recognizing the active role of survey methods in data creation and the importance of understanding the biases inherent in data. Copyright © Crown Copyright 2002. Recorded with the permission of the controller of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.

Geoarchaeology of the Milfield Basin, northern England; towards an integrated archaeological prospection, research and management framework

Abstract: This paper presents the results of geoarchaeological investigations undertaken on the valley floor of the Milfield Basin in Northumberland, northern England. The area has a regionally and nationally important archaeological record, including a series of major neolithic and Anglian settlements, but has hitherto lacked archaeological assessment and management guidelines appropriate to the wide range of late-glacial and post-glacial environmental settings in the basin. This project has used geomorphological techniques to delimit and classify a total of nine valley floor landform elements in terms of their geomorphology and their known and potential archaeological and palaeoenvironmental associations. Terraced glaciodeltaic and glaciofluvial sand and gravel landforms comprise the oldest landform elements described here and have formed the primary regional focus for prehistoric and early historic settlement and associated subsistence and ritual activity. These landforms have experienced little post-glacial geomorphological activity, but their multiperiod archaeological landscapes lie beneath a shallow soil cover and are vulnerable to land-use activities that disturb terrace soils and underlying sediments. A second group of landform elements are of Holocene age and include localized surface peats, alluvial fans, colluvial deposits and extensive deposits of terraced alluvium. Archaeological landscapes in these environments may lie buried intact and unrecorded beneath protective covers of sediment although locally they may have been subject to erosion and reworking by fluvial and slope processes. Holocene alluviation may account, at least in part, for the paucity of recorded archaeology in these parts of the basin. However, peat and organic-rich sedimentary sequences identified here (including four 14C dated peat sequences) offer an opportunity to elucidate the environmental context and land-use histories of local prehistoric and early historic communities in the basin, and hence also should be regarded as an archaeological resource. Discussion of landform elements and their archaeological associations is followed by a brief outline of evaluation criteria developed with the aim of ensuring effective long-term management of archaeological and palaeoenvironmental resources. It is concluded that geoarchaeological analysis of landform elements may be considered central to development of frameworks intended to underpin future programmes of archaeological research and the development of cultural resource management and evaluation strategies. Copyright © 2002 John Wiley & Sons, Ltd.

Magnetic mapping and dating of prehistoric and medieval iron-working sites in northwest wales

Abstract: As part of a long-term research project on prehistoric and medieval iron-working sites in northwest Wales, a technique has been developed for processing magnetic survey data to improve the presentation and recognition of the high-amplitude dipolar signals that are characteristic of iron-smelting furnaces. This technique has now been used successfully on some 37 British iron-working sites. High-resolution surveys, on a 10-cm grid, have been made both by caesium magnetometer and fluxgate gradiometer over four prehistoric furnaces and one medieval furnace giving detailed maps of their magnetic signals. Mathematical models of these maps, using multiple dipoles, has given estimates of the directions of total magnetization of the furnaces. Three of the furnaces were also surveyed at subsequent stages of excavation and after the removal of the furnace, giving the background signal. The background signals can then be subtracted from the survey data to give clean residual maps. These are easier to model, giving more reliable results, and they give useful information on the contribution of the different furnace materials to the overall magnetic signals. The corrections required for the influence of induced magnetism and for viscous remanent magnetism are examined. The results are compared with the British archaeomagnetic curve, and with the archaeomagnetic date estimates from three of the furnaces, to assess the value of the modelling technique in giving usable estimates of the date of last firing of the furnaces. Copyright © 2002 John Wiley & Sons, Ltd.

Ground-penetrating radar and magnetic survey to the west of Al-Zayyan Temple, Kharga Oasis, Al-Wadi Al-Jadeed (New Valley), Egypt

Abstract: Al-Zayyan Temple or Qasr Al-Zayyan might be regarded as one in a chain of several fortresses that the Romans built to secure the salver's trade caravan route between Asyut and Sudan, known as Darb Al-Arbain. Al-Zayyan temple lies about 25 km south of Al-Kharga city, the capital of the New Valley, and deviates to the east of Al-Kharga-Paris main road some 2 km along the Al-Zayyan-Aarif minor road. The background information about the temple is very scarce, and even what is known is neither clear nor accurate. Some indications have ascribed it to Amenebis and that it was restored during the reign of Emperor Antoninus (AD 138–161). An integrated ground-penetrating radar (GPR)survey using the SIR 2000 Geophysical Survey Systems, Inc. (GSSI) together with magnetic survey using FM36 (GeoScan) and the three component fluxgate gradiometer TRM-70D (Tokin) have been applied to the western side of the temple. The results show relatively large-scale buried structures in a direction intersecting that of the present temple at about 45°. Some particular features within the structure have been speculatively ascribed on the basis of comprehending their signatures in the GPR sections. The magnetic results have improved the identification of some objects revealed by the GPR and provided ideas about some of the other features. Copyright © 2002 John Wiley & Sons, Ltd.

Comparison of seismic reflection and ground‐penetrating radar imaging at the controlled archaeological test site, Champaign, Illinois

Abstract: Shallow seismic reflection and ground-penetrating radar images were collected at a replicated burial mound in the Controlled Archaeological Test Site (CATS) in Champaign, Illinois. The CATS mound contains a pig burial within a wood-lined crypt at a depth of 1.6–2.4 m. Seismic reflection data were collected from two different energy sources: a small (0.5 kg) hammer for an impulsive source, and a vibrator for a frequency swept source. Seismic data were collected at densely spaced points (5 cm) along a line of 48 geophone receivers. These data were stacked in a common mid-point gather, band-pass filtered, and processed with frequency–wavenumber migration. The seismic image produced by the hammer source was dominated by bodywaves at 120 Hz, whereas the vibrator source image was dominated by surface waves at 70 Hz. Both seismic sources revealed clear reflections from the burial crypt, and placed the top of the crypt at the correct depth with a seismic velocity of 120 m s−1. The bottom of the crypt was poorly defined by the seismic data owing to multiple reflections within the crypt. The vibrator source also revealed a high-frequency (360 Hz) reflector at 2.7 m depth within the mound, perhaps due to a resonant cavity within the pig's body. Single channel ground-penetrating radar data were processed with the same approach, including band-pass filtering and migration. The radar data reveal clear reflections from the burial crypt. Extremely fast radar velocities (260 mm ns−1) are required in the upper portion of the burial mound to place the top of the crypt at its correct depth. The bottom of the crypt was well defined by ground-penetrating radar, and was located accurately with respect to the top of the crypt with a moderate radar velocity (170 mm ns−1). The application of both seismic reflection and ground-penetrating radar to the same site may be beneficial for improved understanding of their abilities for shallow subsurface imaging. Copyright © 2002 John Wiley & Sons, Ltd.

Structural layout of the suburbs of Roman Butrint, southern Albania: results from a gradiometer and resistivity survey

Abstract: Butrint, a World Heritage Site in southern Albania, encompasses 3000 years of Mediterranean history from the Hellenistic Greeks to the Venetians. In Roman times a suburb of Butrint spread out across the marsh plain to the south of the city, where approximately 20 ha have been surveyed with a fluxgate gradiometer, and 4 ha with a ground resistivity meter. The magnetic anomalies show that the line of the aqueduct into the centre of Butrint is evident for part of this area, but the aqueduct signature becomes progressively less distinct on approaching the Vivari Channel, probably owing to deeper burial. A complex of confused, short-wavelength anomalies, but with some linear elements covers about 3 ha and is associated with exposed building remains. The abrupt termination of these anomalies to the west may be associated with the former Roman water front. Isolated smaller areas of magnetic anomalies up to 0.5 ha in the area surveyed, show buildings and associated ditches away from the main complex. The resistivity survey allows some detailed constraints on the position of buildings in the densely occupied area. Analysis of the orientation of linear anomalies indicates there are two co-genetic sets of magnetic and resistivity linear anomalies. A strong NW-SE and weaker NE-SW set, which parallel the aqueduct and the alignment of standing walls. This set appears to indicate a regular building alignment across the whole site, which is reflected in the orientation of the few current standing walls on the site. This set may post-date the building of the aqueduct, because these reflect the latest standing remains on the site. A second stronger set of E-W and (subsidiary) N-S linear anomalies may signify either an early system of streets, or perhaps an agricultural-based ditch system developed prior to the buildings on the site. This second set may pre-date the building of the aqueduct in the first century BC, when Butrint became a Roman colony. An alternative interpretation suggests part of the suburbs street plan may be based on a non-conventional triangular network of roadways, the design of which may have been emulated in the construction of the medieval Triangular Castle. Copyright  2002 John Wiley & Sons, Ltd.

Remote detection and identification of organic remains: an assessment of archaeological potential

Abstract: This paper reviews the various methods of using natural or induced light spectra as analytical tools in forensic archaeology. Chemical identification can be made at long range and wide scale (tens of metres) down to short range and very small scale (nanometres). The identification of organic gases and materials has used either chemical capture and chromatography, induced (laser or ultraviolet) light sources or laser Raman microscope spectroscopy. The remote gas detection method relies on the identification of atmospheric gases by their characteristic light spectra. Modern spectroscopes can detect gases down to a few parts per million of an atmosphere. When the light source (wavelength) and direction is controlled, so laser-induced spectroscopy may be used to monitor the emission of gases such methane from buried organic remains. In order to identify the location of buried organic remains, a grid of sample points must be established using a base line or global positioning system. When matched to base line or ground-positioning systems, such data can be manipulated by geographical information system packages. This would enable pinpointing of anomalies for excavation or avoidance. Microscope-based laser Raman spectroscopy can be used to directly analyse captured gases, swabs and surfaces without the problems of long-path detection. Copyright © 2002 John Wiley & Sons, Ltd.

Archaeogeophysical investigations around the Bilge Qagan monument in Khosho Tsaidam, Mongolia

Abstract: Ancient Turkish monuments in Mongolia are historically important owing to the earliest Turkish and Chinese inscriptions written on them. In this paper, magnetic and conductivity meter surveys conducted in the vicinity of the Bilge Qagan monument are presented. Magnetic and conductivity maps show rectangular shaped anomalies, which could be caused by a buried wall-like structure or floor tiles to protect the Bilge Qagan monument. The Altar Stone, which is also described as a base for a pagoda, gives a strong magnetic anomaly. This anomaly is processed by advanced geophysical methods and it is demonstrated that the actual rock body has some form of remanent magnetization, which causes the magnetic anomaly. By means of conductivity surveying, it also can be suggested that the near-surface formations have significant water content. Copyright © 2002 John Wiley & Sons, Ltd.

The geophysical evaluation of British lead and copper working sites. Comparisons with iron working

Abstract: Recent research at the University of Bradford has been very effective in evaluating early iron-working sites using geophysical techniques. In addition, lead and copper smelting sites have been surveyed with a fluxgate gradiometer. Although the fluxgate gradiometer readings from these sites are lower than those from iron-smelting sites it is possible to identify anomalies related to the different smelting methods. The paper provides details of some of the surveys and the different features that may be identified. Magnetic susceptibility measurements of selected slag samples provided additional information. Copyright © 2002 John Wiley & Sons, Ltd.

Geophysical Prospection Survey of an Ancient Amphorae Workshop at Tsoukalia, Alonnisos (Greece)

Abstract: At Tsoukalia, Alonnisos, there are substantial remains of a fourth century BC transport amphora production site, consisting of dense surface scatters of ceramics and kiln debris. Typological studies have shown that Tsoukalia, together with other major coastal amphora workshop centres in the area of Sporades islands, participated in a trade network extending up to the Black Sea. The archaeological investigations in the area of the workshop, initiated in 1999, included surface survey, ethnographical studies, topographic mapping, geomorphological studies and geophysical survey. Geophysical techniques included magnetic (both fluxgate gradiometer and caesium gradiometer) and electromagnetic techniques and the application of ground-penetrating radar. Geophysical prospection was used to locate areas of specific archaeological interest and map the subsurface architectural remains of the site, enhancing the reconstruction of the diachronic land use of the site and the wider area of interest and contributing to the further understanding of the economic patterns of ancient Ikos. Copyright © 2002 John Wiley & Sons, Ltd.

Statistical quality control in archaeological survey

Abstract: This paper proposes a statistical method to establish the quality of the results in archaeological survey. A random sample, a simple statistical operation and the use of standard tables, adapted to this kind of work, allow us to determine when the archaeological prospection has an acceptable quality or not. This kind of investigation has never been undertaken in archaeology, but it will be of the most suitable use in the future to know the reliability of the results for scientific or heritage purposes. Copyright © 2002 John Wiley & Sons, Ltd.

Geoelectrical investigation beneath Behbiet ElHigara and ElKom ElAkhder archaeological sites, Samannud area, Nile Delta, Egypt

Abstract: Geoelectrical resistivity and resistance geoscanning techniques were conducted on Behbiet ElHigara and ElKom ElAkhder archeological sites for two purposes. The first was aimed to study the palaeohydrography and the subsurface geological picture of these sites; for this purpose, 19 vertical electric soundings were conducted along two E–W profiles across the sites. The results indicate that both archaeological sites represent buried high sand gizeras occupied by the ancient Egyptians as they were safe from the high floods and near to the freshwater courses that passed by the sites. The second purpose was to delineate any buried archaeological remains under the soil. For this purpose, resistance geoscanning survey was conducted on the two sites, together with three detailed and shallow geoelectric resistivity profiles along ElKom ElAkhder for more confirmation. The results indicate that the low-resistivity clayey deposits predominate on the two sites. Behbiet ElHigara is characterized by shallow, circular and small-extent anomalies that could be referred to small granitic blocks at shallow depths, whereas at ElKom ElAkhder, a high resistivity anomaly embedded within a low resistivity clayey facies was noticed: this could represent the buried sand gezira (islet) of ElKom ElAkhder. Copyright © 2002 John Wiley & Sons, Ltd.

Archaeological geophysics in East Anglia, UK

Abstract: Geophysical surveying in East Anglia has proven to be less successful than in other parts of the UK, and this is attributed to the soils in the region, which tend to contain much gravel and sand. However, some interesting results have been obtained using both resistivity and magnetometry. Three examples are given, at Caistor St Edmund, Norfolk, Pleshey, Essex, and Gosbecks, Colchester, Essex. Copyright © 2002 John Wiley & Sons, Ltd.

Archaeomagnetic surveys of the anonymous graves in Khosho Tsaidam, Mongolia

Abstract: There are ancient graves in the Khosho Tsaidam region of Mongolia, in the vicinity of historical Turkish monuments. The geological setting of the region is indicative of a marshland with partitioning of the Orkhun River into two branches. Magnetic surveys were carried out at two of the anonymous graves to decipher their origin and possible relationship with the old Turkish temples. Grey images of the magnetic anomaly maps are produced to enhance the contour maps with reduced ranges. The grey image maps display visible rectangular and square shaped lineaments. In both of the graves, high-frequency areas, thought to be caused by fired floor tiles, are observed and these features resemble one of the Turkish monuments recently surveyed. Copyright © 2002 John Wiley & Sons, Ltd.