Prospection Of Archaeological Sites Research Articles

Geospatial integration in mapping pre-Hispanic settlements within Aztec empire limits

Mexico’s vast archaeological research tradition has increased with the use of remote sensing technologies; however, this recent approach is still costly in emerging market economies. In addition, the scales of prospection, landscape, and violence affect the type of research that heritage-culture ministries and universities can conduct. In Central Mexico, researchers have studied the pre-Hispanic Settlement Pattern during the Mesoamerican Postclassic (900-1521 AD) within the scope of the Aztec Empire and its conquests. There are settlements indications before and during the rule of the central empire, but the evidence is difficult to identify, particularly in the southwest of the capital, in the transition between the Lerma and Balsas River basins and their political-geographical complexities. This research focuses on a Geographic Information System (GIS)-based processing of multiple source data, the potential prospection of archaeological sites based on spatial data integration from Sentinel-2 optical sensors, Unmanned Aerial Vehicle (UAV), Digital Terrain Model (DTM), Normalized Difference Vegetation Index (NDVI) and field validation. What is revealed is the relationship between terrain morphologies and anthropic modifications. A binary map expresses possible archaeological remnants as a percentage; NDVI pixels and the morphometry values were associated with anthropic features (meso-reliefs with a tendency to regular geometries: slope, orientation, and roughness index); they were then interpreted as probable archaeological evidence. Within archaeological fieldwork, with limited resources (time, funding and staff), this approach proposes a robust method that can be replicated in other mountainous landscapes that are densely covered by vegetation.

Shallow Offshore Geophysical Prospection of Archaeological Sites in Eastern Mediterranean

Geophysical prospecting methods have been extensively used to outline buried antiquities in terrestrial sites. Despite the frequent application of these mapping and imaging approaches for the detection of archaeological relics in deep-water marine environments (e.g., shipwrecks), the aforementioned processes have minimal contribution when it comes to understanding the dynamics of the past in coastal and shallow aquatic archaeological sites. This work explores the possibilities of multicomponent geophysical techniques in revealing antiquities that have been submerged in diverse shallow coastal marine environments in the eastern Mediterranean. A group of four sites in Greece (Agioi Theodoroi, Olous, Lambayanna) and Cyprus (Pafos) spanning from prehistory to Roman times were chosen as test sites to validate the efficiency of electrical resistivity tomography, magnetic gradiometry, and ground penetrating radar methods. The comprehensive analysis of the geophysical data completed the picture for the hidden archeological elements in all the sites. The results manifest the significance and the potential of these methods for documenting and understanding the complex archaeological sites encountered in the Mediterranean. In view of climate change and the risks related to future sea level rise and erosion of low-level coastal areas, the results of this work could be integrated in a strategic framework to develop an effective interdisciplinary research model that can be applied to similar shallow water archaeological surveys, thus substantially contributing towards cultural resources management.

A multi-scalar approach to marine survey and underwater archaeological site prospection in Murujuga, Western Australia

During the past 20,000 years approximately one-quarter of the continental landmass of Australia was inundated by postglacial sea-level rise, submerging archaeological evidence for use of these landscapes. Underwater archaeological sites can offer substantial insights into past lifeways and adaptations to rapidly changing environments, however the vast scale of inundation presents a range of challenges in discovering such sites. Here we present a suite of methods as a model methodology for locating sites in submerged landscapes. Priority areas for survey were based on palaeoenvironmental contexts determined from the onshore archaeological record. Remote sensing was used to identify seabed composition and indicators of palaeolandscapes where high potential for human occupation and site preservation could be identified in Murujuga (or the Dampier Archipelago), northwestern Australia. Target locations were surveyed by scientific divers to test for the presence of archaeological material. Application of this methodology resulted in the discovery of the first two confirmed sub-tidal ancient Aboriginal archaeological sites on Australia's continental shelf. Survey methods are discussed for their combined value to identify different classes of landscapes and archaeological features to support future underwater site prospection.

The Use of Remote Sensing, Geophysical Methods and Soil Analysis in the Study of Sites Disturbed by Agricultural Activity

This study is based on an interdisciplinary approach to the prospection of archaeological sites impacted by modern agricultural plowing activity. We applied remote sensing, combined with geophysical, geochemical, and archaeological methods at Kushmanskoye III — a medieval Finno-Ugric site in the Cheptsa River basin, northern Udmurtia (9th–13th centuries AD). As a result of many years of plowing, the site cannot be visually demarcated, and visual traces of its extent have been obliterated. Scientifi c methods included aerial photography from unmanned vehicles (visual range, thermal, and multispectral imaging), geophysical techniques (resistivity and magnetometry surveys, ground penetrating radar, and electrical resistivity tomography), and soil studies (grain size composition, micromorphology, and chemical and biological analyses of soil cores). As a result, we effectively traced the boundaries of the site and of its “household periphery”, delineating areas with various degrees of disruption. Our research identifi ed two lines of defensive constructions, previously invisible on the surface. Our fi ndings have enabled us to initiate revision of the site’s status in the register of state-protected archaeological resources. The location of geophysical anomalies, caused by buried features, reveals a regularized row layout to the site. The results are supported by those of archaeological surveys.

High-resolution remote sensing and advanced classification techniques for the prospection of archaeological sites’ markers: The case of dung deposits in the Shashi-Limpopo Confluence area (southern Africa)

Archaeological prospection through remote sensing is based on the contrast between areas of archaeological interest and their surroundings. It has been used as the cheapest and the fastest way of locating and documenting areas of archaeological interest since the 1920s, initially with the aid of film-based aerial photographs. In recent years, there has been a shift towards the use of multispectral satellite data in prospecting for archaeological sites because of their ability to give information on spectral characteristics of archaeological material beyond the visible spectrum. However, spectral signatures for identifying archaeological sites are not universal, and an assessment of the applicability of remote sensing techniques in different archaeological landscapes is needed. This study tests the feasibility of prospecting for archaeological sites previously occupied by farming communities in the Shashi-Limpopo Confluence Area of southern Africa, using very high-resolution satellite WorldView-2 images. It also assesses the performance of advanced classification algorithms (support vector machine and random forest) and the contribution of new WorldView-2 bands in detecting archaeological sites. Two independent accuracy assessments were carried out, using a data set collected by Huffman (2011, 2009a) and a randomly generated holdout test dataset, respectively. The results demonstrate the potential of remote sensing methods in prospecting for archaeological sites previously occupied by farming communities using very high-resolution satellite images and advanced classification algorithms. Very high overall accuracies were achieved by: random forest, 95.29% using holdout sample and 97.71% using independent dataset; support vector machine, 88.82% using holdout sample and 95.88% using independent dataset, respectively. The new WorldView-2 bands were of least importance (compared to traditional bands) in detecting sites in Shashi-Limpopo Confluence Area. Despite high classification accuracies achieved by both classifiers, there were some misclassifications between vitrified dung sites and river sand. Therefore, to address this problem, this study recommends the use of robust classifiers such as object-based algorithms because of their ability to segment an image into homogenous objects and classify them using a combination of spectral, textual, sub-pixels, spatial, relational and contextual methods.

A ‘Reflexive’ Multi-Stage Survey Methodology for Historical Landscape Research in Central India:Field-Walking, Local Knowledge, and Satellite Imagery as Archaeological Site Prospection and Mapping Tools in the Sanchi Survey Project

This paper evaluates the relative usefulness of systematic v. unsystematic fieldwalking, local knowledge frameworks and satellite imagery as archaeological prospection and mapping tools for the Sanchi Survey Project (SSP) in Central India. Whilst the satellite imagery proved helpful as a supplementary site-prospection and mapping tool during later phases of the project, initial site identification was more effectively facilitated through ground-based explorations, and a ‘reflexive’ approach that included a sensitivity to local memory and the continued currency of archaeological sites in today’s socio-ritual landscape. Set within discussions on the role of the local in ‘reflexive’ field methodologies, and broader public archaeology debates, the paper stresses the importance of local perceptions of place and history in the development of a regionally specific research design.

Posterior Probability Modeling and Image Classification for Archaeological Site Prospection: Building a Survey Efficacy Model for Identifying Neolithic Felsite Workshops in the Shetland Islands

The application of custom classification techniques and posterior probability modeling (PPM) using Worldview-2 multispectral imagery to archaeological field survey is presented in this paper. Research is focused on the identification of Neolithic felsite stone tool workshops in the North Mavine region of the Shetland Islands in Northern Scotland. Sample data from known workshops surveyed using differential GPS are used alongside known non-sites to train a linear discriminant analysis (LDA) classifier based on a combination of datasets including Worldview-2 bands, band difference ratios (BDR) and topographical derivatives. Principal components analysis is further used to test and reduce dimensionality caused by redundant datasets. Probability models were generated by LDA using principal components and tested with sites identified through geological field survey. Testing shows the prospective ability of this technique and significance between 0.05 and 0.01, and gain statistics between 0.90 and 0.94, higher than those obtained using maximum likelihood and random forest classifiers. Results suggest that this approach is best suited to relatively homogenous site types, and performs better with correlated data sources. Finally, by combining posterior probability models and least-cost analysis, a survey least-cost efficacy model is generated showing the utility of such approaches to archaeological field survey.

Using satellite image analysis for locating prehistoric archaeological sites in Alaska's Central Brooks Range

In this pilot study, we apply satellite image analysis to archaeological site prospection in Alaska's Brooks Range. Our goal was to test whether satellite remote sensing, which has been successful in locating large archaeological features associated with sedentary peoples, could be applied to arctic interior sites associated with mobile hunter–gatherers. In particular, we strove to develop a relatively straightforward and inexpensive model using existing data which could be used to help guide archaeology surveys. Using 1-m resolution IKONOS imagery of Lake Matcharak along the upper Noatak River, we produced a Normalized Difference Vegetation Index (NDVI) and tasseled cap transformation of the study area and stacked these five vegetation indices into one image. We then applied unsupervised and supervised classifications to the image first, to test for the presence of a site-specific spectral class and second, determine the nature of that class. Through a visual analysis of the unsupervised classification, a spectral phenomenon was seen to co-occur with archaeological sites in the study area. The supervised classification provided a high-resolution land cover map used to identify the signature as the ecotone between un-vegetated sediments and dense willow (Salix sp.) stands. Dense willow stands along the Lake Matcharak shore visually correlate with most of the known archaeological sites, possibly reflecting landform and/or vegetation characteristics that would have appealed to past inhabitants. The methods described here could contribute to building better survey strategies and archaeological predictive models for elsewhere in the Brooks Range and Alaska.

Parameters in the use of pXRF for archaeological site prospection: a case study at the Reaume Fort Site, Central Minnesota

Field portable/hand-held x-ray fluorescence (pXRF) analyzers have been characterized as potentially useful for archaeological site prospection, but little has been published on the parameters of their use in this manner. The purpose of this study is to explore whether the variability of surface geochemistry as characterized with a pXRF analyzer corresponds with subsurface archaeological features at a site subsequently excavated, and what conditions influence the success of this endeavor, including feature depths, soil moisture, and sample processing. A 520 m2 within-site area was systematically surveyed on a 2 m interval, within which several types of archaeological features were excavated (chimney bases, wall trenches, and a bonebed of faunal waste), taking readings in situ and collecting samples for ex situ testing (undried, dried but not powdered, and dried/powdered). The four different tests of each grid location, analyzed through univariate and multivariate tests, showed that the pXRF surface data does correspond with some types of subsurface features when those features are very shallow (within 5 cm of surface level) and are associated with clayey fills. Further, the data from the subsurface samples provides excellent distinction of feature fills from other sediments, regardless of sample preparation. In situ surface survey with pXRF analyzers may however be adequate for sites with a thorough baseline geochemical database.

Recent achievements and trends of research for geophysical prospection of archaeological sites

Our times are characterized by an increasing need for prospection particularly within the context of rescue archaeology. Geophysics has an important part to play due to its ability to identify some well defined targets as well as to investigate large areas. Several recent surveys, using carefully selected methods chosen in accordance with the type of expected remain or a combination of methods in order to refine or confirm the interpretation, have demonstrated the expertise of several organisations in a wide variety of archaeological contexts. However, important improvements are still to be expected from the laboratories. Our team, working within the framework of three dissertations, is investigating several original subjects, for which the initial results are presented and discussed here: (1) The use of magnetic susceptibility measurements on wide mesh grids in order to survey extensive areas immediately prior to their occupation or destruction by large modern equipment; (2) Experiments to test a new survey device (Slingram - CS150) able to measure the magnetic susceptibility of the ground; (3) Interpretation of a series of geophysical measurements integrated with other types of data into a G.I.S.

Relationships between human activity and the magnetic properties of soils: a case study in the medieval site of Roissy-en-France

Magnetic prospection of archaeological sites depends strongly on the susceptibility, χm, of the upper layer of soils and on their ferrimagnetic mineral content. The minerals involved may be authigenic, biogenic or anthropogenic (by firing). To characterize and identify different ferrimagnetic minerals in several archaeological soils, we performed thermomagnetic and hysteresis measurements on a set of samples. Pedological and micromorphological analyses allow us to determine the relationship between pedological and human activities (ferruginization and anthropogenic objects) and their magnetic parameters. Maghemite was identified by the thermomagnetic curves as the main ferrimagnetic mineral in these archaeological sediments. The link between ferruginization and high magnetic susceptibility is complex. However, a correlation between the ratio of susceptibility to saturation magnetization, χm/Js, and the abundance of anthropogenic objects was observed. In association with magnetic susceptibility and remanent coercive field, we can provide an estimation of human alteration of the sediments. The thermomagnetic curves and a comparison between heated natural sediment and the anthropogenically altered sediments may provide an estimate of the furnace temperature. Copyright © 1999 John Wiley & Sons, Ltd.

Geophysical prospection of archaeological sites in Brandenburg, Germany

Over the last few years archaeologists have collected considerable knowledge about several sites in Brandenburg by aerial photography. In addition they have carried out geophysical prospection in order to obtain more information about interior structures, depth ranges and physical properties. Several circular ditch systems were investigated in different geological areas. In the south of Brandenburg there is a Neolithic ditch system, which produces significant magnetic anomalies of about 2–5 nT m−1 (fluxgate gradiometer) and thus it is possible to detect not only the main structures but also some palisades. In the eastern part of Brandenburg there are two sites that are also supposed to be of neolithic origin. One of them responds fairly well to the magnetic method, but there are some parts that can be seen only in aerial photographs. The other site is covered by Ortstein (cemented sandstone with oxides), which makes magnetic investigations impossible. Because of the higher conductivity correlating with higher humidity within a ditch system, however, such structures can be prospected with the help of the electromagnetic method and georadar. This correlation leads to the conclusion that former ditches can be prospected not only outside built-up areas but also within a city using the direct current electrical method. Copyright © 1999 John Wiley & Sons, Ltd.