Archaeological Prospection Research Articles

Aerial Bombing Crater Identification: Exploitation of Precise Digital Terrain Models

Places of past conflicts and persistent objects that reflect such events often attract the attention of archaeological prospection which facilitates the construction of conflict narratives. Field prospection as a precise method for localization of aerial bombing craters (as an example of such persistent features) is a highly time- and resource-consuming task. Therefore, methods for automatic identification of such features are evolving. We present a comparison of three methods for possible automatic crater detection based on (a) extraterrestrial crater detection algorithms, (b) geomorphology-based edge extraction, and (c) image pattern recognition via a state-of-the-art convolutional neural network (CNN). All methods were preliminarily tested on a case study of eight Second World War (WWII) aerial bombing crater sites in NW Czechia via Airborne Laser Scanned LiDAR-derived digital terrain models with different spatial resolutions. We found that extraterrestrial crater detection algorithms and geomorphology-based edge extraction methods yield worse results given the standard indices of precision and recall. By comparison, the CNN method utilized for a particular task achieved satisfying results, predominantly with 0.5 m/px resolution (which is often available at the country level) of the input raster. Nevertheless, overall performance with this resolution varies significantly among the sites. Therefore, the quality and readability of the input data are crucial factors for the successful acquisition of precise ordinance location identification.

New Perception to Proto History Burial Site in Andarawewa: An Archaeological and Geochemical Prospection

The megalithic burial site at Galgamuwa Andarawewa is situated at Anamaduwa Secretariat Division in the North Western Province, Sri Lanka. It is evident that 2500 years ago the proto history people had settled in this region. For burying of bodies, they have constructed different types of burials in several places in this region. Thus, to examine the geochemical prospection soil samples from the context (n=12), the glass bead samples from the furnace (n=3) and slag (n=2) were analyzed using X-Ray Fluorescence (XRF) for 22 major and trace elements. For the archaeological prospection, new findings of proto-history burials were found in the excavation carried out at Andarawewa and also many archaeological evidences were found through the field survey and excavations such as beads, inscriptions, pots and shard and chisels. The elemental values of the slag show that, Pb (470-483 mg/Kg) and Cu (855-1083 mg/Kg) are very much higher than Upper Continental Crustal Values. The white part contains higher Pb and Cu than the dark part of the slag. The concentrations of halides F, Br and I are almost similar in the white (glass) part and dark (slag) part. The Pb, Cu and as in the glass beads of the Andrawewa furnace shows that they range between 390-2920, 275-1411 and 12-127 mg/Kg respectively. However, the Fe and Ti concentrations are much lower than in the contexts though P2O5 is higher in the bead samples. The soil samples from the contexts of the area does not show high values for almost all the measured elements. Thus, indicating that the soils are local while the beads may have been prepared with sands brought from other areas. The carbon dating has dated that this burial belongs to the period from 500- 507 B.C.

Prospects for IXPE and eXTP polarimetric archaeology of the reflection nebulae in the Galactic center

The X-ray polarization properties of the reflection nebulae in the Galactic center inform us about the direction of the illuminating source (through the polarization angle) and the cloud position along the line of sight (through the polarization degree). However, the detected polarization degree is expected to be lowered because the polarized emission of the clouds is mixed with the unpolarized diffuse emission that permeates the Galactic center region. In a real observation, also the morphological smearing of the source due to the point spread function and the unpolarized instrumental background contribute in diluting the polarization degree. So far, these effects have never been included in the estimation of the dilution. We evaluate the detectability of the X-ray polarization predicted for the MC2, Bridge-B2, G0.11-0.11, Sgr B2, Sgr C1, Sgr C2, and Sgr C3 molecular clouds with modern X-ray imaging polarimeters such as the Imaging X-ray Polarimetry Explorer (IXPE), which is expected to launch in 2021, and the Enhanced X-ray Timing and Polarimetry mission (eXTP), whose launch is scheduled for 2027. We perform realistic simulations of X-ray polarimetric observations considering (with the aid of Chandra maps and spectra) the spatial, spectral, and polarization properties of all the diffuse emission and background components in each region of interest. We find that in the 4.0–8.0 keV band, where the emission of the molecular clouds outshines the other components, the dilution of the polarization degree, including the contribution due to the morphological smearing of the source, ranges between ~19% and ~55%. We conclude that for some distance values reported in the literature, the diluted polarization degree of G0.11-0.11, Sgr B2, Bridge-B2, Bridge-E, Sgr C1, and Sgr C3 may be detectable in a 2 Ms long IXPE observations. With the same exposure time, and considering the whole range of possible distances reported in the literature, the enhanced capabilities of eXTP may allow detecting the 4.0–8.0 keV of all the targets considered here.

Trace metals dispersion from 1000 years of mining activity in the northern French Alps

This paper investigates the long-term dispersal of trace metals and their impact on the environment long after mine closure in the French Alps. Three statistical methods derived from modern mining (Exploratory Data Analysis, fractals and Sediment Quality Index) were applied to geochemical analyses of streambed sediments to produce mineral prospectivity maps. About 5% of the samples have a poor or marginal quality and may have an effect on biota. Positive anomalies are either related to the geological background (lithology, major tectonic contacts) or to ancient mining sites. The local impact of former mining was investigated on a medieval Pb–Ag district (Brandes; Pbmax ~8 000 mg kg−1), a small district mined during the 17th–19th c. (Peisey-Nancroix; Pbmax = 583 mg kg−1), and a major modern Pb–Ag mine (Macôt-La Plagne; Pbmax ~ 3 200 mg kg−1).The mining heritage is still traceable in the northern French Alps. The anomalies observed at local scale are related to the volume of extracted ore rather than to the timing and duration of mining, suggesting that old mining sites still release trace metals over centuries and up to a thousand years. The statistical methods used provide a strong tool for archaeological prospection and environmental studies.

Detecting Classic Maya Settlements with Lidar-Derived Relief Visualizations

In the past decade, Light Detection and Ranging (lidar) has fundamentally changed our ability to remotely detect archaeological features and deepen our understanding of past human-environment interactions, settlement systems, agricultural practices, and monumental constructions. Across archaeological contexts, lidar relief visualization techniques test how local environments impact archaeological prospection. This study used a 132 km2 lidar dataset to assess three relief visualization techniques—sky-view factor (SVF), topographic position index (TPI), and simple local relief model (SLRM)—and object-based image analysis (OBIA) on a slope model for the non-automated visual detection of small hinterland Classic (250–800 CE) Maya settlements near the polities of Uxbenká and Ix Kuku’il in Southern Belize. Pedestrian survey in the study area identified 315 plazuelas across a 35 km2 area; the remaining 90 km2 in the lidar dataset is yet to be surveyed. The previously surveyed plazuelas were compared to the plazuelas visually identified on the TPI and SLRM. In total, an additional 563 new possible plazuelas were visually identified across the lidar dataset, using TPI and SLRM. Larger plazuelas, and especially plazuelas located in disturbed environments, are often more likely to be detected in a visual assessment of the TPI and SLRM. These findings emphasize the extent and density of Classic Maya settlements and highlight the continued need for pedestrian survey to ground-truth remotely identified archaeological features and the impact of modern anthropogenic behaviors for archaeological prospection. Remote sensing and lidar have deepened our understanding of past human settlement systems and low-density urbanism, processes that we experience today as humans residing in modern cities.

A Pilot Study on Remote Sensing and Citizen Science for Archaeological Prospection

Cost-effective techniques for systematic archaeological prospection are essential to improve the efficiency of preventive archaeology and the preservation of cultural heritage. Web Mapping Services, such as Microsoft Bing Maps, provide imagery covering extensive areas at high resolution. These can, in some cases, reveal cropmarks of buried historical structures. Given that archaeological prospection is not generally the priority of most common Web Mapping Services, the conditions under which images are acquired are not always suitable for the appearance of cropmarks. Therefore, their detection is typically serendipitous. This pilot project attempts to assess the potential to use the Microsoft Bing Maps Bird’s Eye service within a crowdsourcing platform to systematically search for archaeological cropmarks in the surroundings of the city of Rome in Italy. On this platform, which is hosted by the company Scifabric (Southampton, UK) and based on PyBossa, an Open Source framework for crowdsourcing, members of the public are invited to interpret oblique air photo tiles of Bing Maps Bird’s Eye. While the project is still on-going, at least one seamless coverage of tiles in the area of interest has been interpreted. For each tile, the Bing Maps Bird’s Eye service provides oblique air photo coverage in up to four possible orientations. As of 5 July 2020, 18,765 of the total 67,014 tasks have been completed. Amongst these completed tasks, positive detections of cropmarks were recorded once for 1447 tasks, twice for 57 tasks, and three or more times for 10 tasks. While many of these detections may be erroneous, some correspond with archaeological cropmarks of buried remains of buildings, roads, aqueducts, and urban areas from the Roman period, as verified by comparison with archaeological survey data. This leads to the conclusion that the Bing Maps Bird’s Eye service contains a wealth of information useful for archaeological prospection, and that to a certain extent citizen researchers could help to mine this information. However, a more thorough analysis would need to be carried out on possible false negatives and biases related to the varying ease of interpretation of residues of different archaeological structures from multiple historical periods. This activity forms the first part of a research project on the systematic prospection of archaeological cropmarks. The ultimate aim is to reach a critical mass of training data through crowdsourcing which can be augmented and used as input to train a machine learning algorithm for automatic detection on a larger scale.

Identification of Archaeologically Relevant Areas Using Open Geodata

Light detection and ranging (LiDAR) and digital terrain models (DTM) revolutionized archeological prospection in the last two decades. Using the new technique, comprehensive areal detections of archeological relief structures (field monuments) hidden under dense vegetation became possible and archeologists found new sites even in well-known areas. In times of Open Geodata policies, archeologists have access to geospatial data sets such as DTM. Assessing its full potential requires automated workflows, which is a recent research topic in archeological research. However, all approaches, both manually and automated, are affected by misclassifications caused by confusions of archeological and modern structures. Digital landscape models (DLM) help differentiating structures by their location. Concerning these data, only 74% of the total area of Westphalia and Lippe need archeological investigation, increasing precision of automated classification approaches.

Recognition method of typical anomalies during karst tunnel construction using GPR attributes and Gaussian processes

Ground penetrating radar (GPR) is a geophysical exploration technique used in a wide range of applications such as polar exploration, hydrogeological surveys, and archeological prospection. In recent years, it has been applied to tunnel construction for forecasting geological anomalies in front of the tunnel face. However, the application of GPR, forecasting geological anomalies in karst tunnels, has always been restricted by the problem of ambiguity. In the paper, based on the GPR investigation of highway tunnels in the karst areas in Guangxi, China, several GPR data of typical karst geological anomalies were selected as the analysis objective. The purpose of this study is twofold: to analyze and summarize the GPR attribute characteristics of typical geological anomalies by studies of laboratory tests and to introduce a new method for identifying different types of karst geological anomalies automatically in karst tunnel construction. Firstly, the attribute analysis technology of GPR is introduced, and the propagation law of electromagnetic waves in karst geological anomalies is studied from three perspectives: the time domain, frequency domain, and time-frequency domain by using physical laboratory simulations. Then, an intelligent identification model for typical karst geological anomalies is established in accordance with a Gaussian process (GP). Results from the Gaussian classification of field cases indicate that the type of typical karst geological anomalies can be effectively identified via comparing model prediction probability. The findings of this research allow for quantitative description of the GPR interpretation of typical karst geological anomalies in tunnel advanced prediction.

Archaeological Investigation at the Urartian Sites of Bastam Castle Using Magnetics Method

Archaeological Investigation at the Urartian Sites of Bastam Castle Using Magnetics Method

A UAV-borne magnetic survey for archaeological prospection of a Celtic burial site

A UAV-borne magnetic survey for archaeological prospection of a Celtic burial site

Geological Challenges of Archaeological Prospecting: The Northern Peloponnese as a Type Location of Populated Syn-Rift Settings

The Northern Peloponnese is not only home of a series of ancient poleis that are being studied by archaeologists, but it is also located on the southern shoulder of the most active extensional crustal structure in the world; the Corinthian rift. This rift has shaped the Northern Peloponnese as we now see it today since the Pliocene. Normal faulting, the tectonic uplift of syn-rift sediments and sea level changes, has shaped a landscape of steps rising from the coast to the ridges in the hinterland that provides challenging conditions to a geophysical survey. Where we can find coarse grained slope and delta deposits of conglomerate on top of banks of marl on ridges and slopes, the lower marine terraces and the coastal plain as well as valleys show the protective caprock eroded and the marl covered by young alluvial deposits. These materials show only a small contrast in their magnetic properties, which reduces the importance of magnetic mapping for the archaeological prospection in this region. The human utilization of the coastal plain and the urban areas pose additional challenges. These challenges have been overcome through various approaches that are shown in exemplary case studies from Aigeira and Sikyon. Whereas a combination of magnetic mapping and ground-penetrating radar (GPR) works very well on the ridges and along the slopes where we find coarser sediments in addition to the magnetic mapping, it is not suitable in the coastal plain due to the attenuating properties of the alluvial sediment. Here, electrical resistivity tomography (ERT) proved to be very successful in mapping entire parts of a settlement in great detail. Seismic soundings were also sucessfully applied in determining the bedrock depth, the detection of walls and in the question of locating the harbor basin. In the presented six exemplary case studies, the following findings were made: (1) A fortification wall and building foundations at a depth of 0.4–1.2 m on a plateau northwest of the acropolis of Aigeira was found by 400 MHz GPR. (2) A honeycomb-shaped pattern of magnetic anomalies that suggested cavities could be identified as a weathering pattern of conglomerate rocks. (3) A rock basement 2.3 m deep and remains of an enclosing wall of the Aigeira theater area were found by shear wave refraction measurements. (4) Extensive ERT surveys detected several building remains in Sikyon like a potential building and grave monuments as well as several small houses. (5) A silted-up depression in the sediments of the coastal plane located through Love wave measurements, could be taken as evidence for either a silted harbor or a navigable riverbed.

If the archaeological context is missing: the use of LiDAR prospection to uncover features at the medieval Christian position on Malvecino Hill (Alcalá de Henares, Spain)

AbstractThe ongoing study of the Andalusian castle of Alcalá la Vieja (Alcalá de Henares, Madrid, Spain) continues to provide new insights about this Muslim fortress. However, the investigation of other battlefield locations around this stronghold, such as Malvecino Hill, have remained in the background. As the site where the Christian army built a temporary castle, Malvecino played a decisive role during the siege and conquest of Alcalá la Vieja in 1118 and is a strong candidate for archaeological study.Some early archaeological prospections carried out at Malvecino in the 1970s corroborated the existence of medieval remains. Scholars have debated whether those remains derive from the fortress built by the Christians or to an earlier settlement. Unfortunately, those artefacts and features disappeared and are not available for additional investigation.Given the lack of archeological context, our investigation included the process of locating potential archaeological features in Malvecino Hill using both aerial photography and light detection and ranging (LiDAR) datasets. This article highlights the value of LiDAR prospection as a preliminary step to fieldwork and describes two early medieval structures on Malvecino Hill that were newly revealed by our LiDAR visualization.

Microgravity method in archaeological prospection: methodical comments on selected case studies from crypt and tomb detection

AbstractDetailed and precise measurement of the Earth's gravity field (microgravity method) can be effectively used for the detection and quantification of subsurface voids and/or cavities. There exist a variety of successful applications of the microgravity method in near surface geophysics, namely in geotechnical, environmental and archaeological prospection. Using state‐of‐the‐art ‘microgal’ relative gravity meters, cavities of several metres in each dimension (positioned at a similar depth) can be detected and interpreted. Such objects produce negative anomalies with amplitudes of several tens of microGals (1 microGal = 10−8 m s−2). This contribution is focused on a methodological overview of the most important acquisition and processing steps in archaeological microgravimetry. In the processing of acquired gravimetrical data into a Bouguer anomaly, the so‐called building correction plays an important role, because the gravitational effect of building masses can produce false, usually negative anomalies. Several selected methods for quantitative interpretation are presented, these are based on depth estimation and density modelling. These interpretation methods give satisfactory results in the case of these type of negative anomalies that are caused by subsurface cavities. Microgravimetry can obtain good support from electromagnetic and electrical methods, mainly from ground penetrating radar and electrical resistivity tomography, respectively. Finally, we present successful case‐studies of microgravimetrical detection of crypts in various churches from the Middle Ages and period of Modern History, surveyed during recent decades in Slovakia and Czechia.

The Applicability of an Inverse Schlumberger Array for Near-Surface Targets in Shallow Water Environments

We investigate the applicability of offshore geoelectrical profiling in the littoral zone, e.g., for archaeological prospection, sediment classification and investigations on coastal ground water upwelling. We performed field measurements with a 20 m long multi-electrode streamer in inverse Schlumberger configuration, which we used to statistically evaluate measurement uncertainty and the reproducibility of offshore electric resistivity tomography. We compared floating and submerged electrodes, as well as stationary and towed measurements. We found out that apparent resistivity values can be determined with an accuracy of 1% to 5% (1σ) depending on the measurement setup under field conditions. Based on these values and focusing on typical meter-scale targets, we used synthetic resistivity models to theoretically investigate the tomographic resolution and depth penetration achievable near-beach underneath a column of brackish water of about 1 m depth. From the analysis, we conclude that offshore geoelectric sounding allows the mapping of archaeological stone settings. The material differentiation of low-porosity rock masses < 15% is critical. Submerged wooden objects show a significant resistivity contrast to sand and rocks. Distinguishing brine-saturated sandy sediments from cohesive silty-clayey sediments is difficult due to their equal or reversed resistivity contrasts. Submarine freshwater discharges in sandy aquifers can be localized well, though difficulties may occur if the seafloor encounters massive low-porosity rock masses. As to the measurement setups, submerged and floating electrodes differ in their spatial resolution. Whereas stone settings of 0.5 to 1 m can still be located with submerged electrodes within the uppermost 4 m underneath the seafloor, they have to be >2 m if floating electrodes are used. Therefore, we recommend using submerged electrodes, especially in archaeological prospection. Littoral geological and hydrogeological mapping is also feasible with floating electrodes in a more time-saving way.

Remote Sensing Materials for a Preliminary Archaeological Evaluation of the Giove Countryside (Terni, Italy)

A collaboration between the American University of Rome, the Municipality of Giove, and Soprintendenza Archeologia, Belle Arti e Paesaggio dellʼUmbria has resulted in an academic project aimed at a preliminary evaluation of a particular area along the Tiber river that straddles the border between Umbria and Lazio. Archaeological prospection methods, such as Unmanned Aerial Vehicle (UAV)-based remote sensing, ground-penetrating radar (GPR), and photogrammetry, have made it possible to better study the landscape with respect to not only the changes the area has undergone recently, but also its evolution during the Roman and Medieval periods, while keeping the main communication route represented by the Tiber river as its fulcrum.

Targeting the Mesolithic: Interdisciplinary approaches to archaeological prospection in the Brown Bank area, southern North Sea

This paper describes some results of the research undertaken over the Brown Bank area during recent (2018/2019) geoarchaeological surveys in the North Sea which included seismic imaging, shallow (vibro)coring and dredging. It examines the benefits of simultaneous high-resolution (0.5 – 1 m) and ultra-high-resolution (10–20 cm) seismic survey techniques and a staged approach to resolving the submerged Holocene landscape in the highest possible detail for the purpose of targeted prospecting for archaeological material from the Mesolithic landscape of Doggerland. The materials recovered from such surveys offer significantly greater information due to an enhanced understanding of the context in which they were recovered. The importance of this information cannot be understated archaeologically, as few locations on land provide the opportunity to recover archaeological finds in situ within preserved landscapes. Moreover, it allows offshore areas of potential human activity to be prospected with some certainty of success.

It takes all kinds of trees to make a forest. Using historic maps and forestry data to inform airborne laser scanning based archaeological prospection in woodland

AbstractWhile airborne laser scanning (ALS) data is a key resource for studying afforested landscapes, other datasets are essential to understanding the character of surveyed areas, and for assessing the reliability of the remote sensed data interpretation. This article presents results of such assessment based on the analysis of contemporary forestry data and historic maps for a study area located south of Polanów, Poland, which was subject of bespoke ALS survey. Forestry data and historic maps were initially used to plan ALS data collection, and thereafter to assess data quality and bias. As a result, the longevity and patterning of afforestation were determined and these correlate with the outputs of interpretative mapping together offering a benchmark methodology for identifying survival zones for prehistoric and early medieval earthworks beyond the extents of early and late modern cultivation. In addition, the data characteristics discussed in this article demonstrate the importance of data analysis and survey methodology to inform the understanding of potential bias in the outputs of ALS surveys of afforested landscapes. By understanding this phenomenon at a local scale, the reliability of the data can be estimated. Given the nationwide availability of forestry data across Europe, as well as extensive coverage of historic maps, the results discussed in this article have a general application. Focusing on areas with the highest survival potential can lead to immediate discovery of premodern monuments, and hence prevent them from extensive, forestry management related, destruction.

Beyond Amplitudes: Multi-Trace Coherence Analysis for Ground-Penetrating Radar Data Imaging

Under suitable conditions, ground-penetrating radar (GPR) measurements harbour great potential for the non-invasive mapping and three-dimensional investigation of buried archaeological remains. Current GPR data visualisations almost exclusively focus on the imaging of GPR reflection amplitudes. Ideally, the resulting amplitude maps show subsurface structures of archaeological interest in plan view. However, there exist situations in which, despite the presence of buried archaeological remains, hardly any corresponding anomalies can be observed in the GPR time- or depth-slice amplitude images. Following the promising examples set by seismic attribute analysis in the field of exploration seismology, it should be possible to exploit other attributes than merely amplitude values for the enhanced imaging of subsurface structures expressed in GPR data. Coherence is the seismic attribute that is a measure for the discontinuity between adjacent traces in post-stack seismic data volumes. Seismic coherence analysis is directly transferable to common high-resolution 3D GPR data sets. We demonstrate, how under the right circumstances, trace discontinuity analysis can substantially enhance the imaging of structural information contained in GPR data. In certain cases, considerably improved data visualisations are achievable, facilitating subsequent data interpretation. We present GPR trace coherence imaging examples taken from extensive, high-resolution archaeological prospection GPR data sets.

Joint interpretation of seismic refraction tomography and electrical resistivity tomography by cluster analysis to detect buried cavities

In the last few years, the geophysical methods of seismic refraction tomography (SRT) and electrical resistivity tomography (ERT) are among the most used geophysical techniques for the reconstruction of subsoil geometries, for the investigation of underground cavities and also for the archaeological prospecting. However, the main disadvantage of each geophysical method is the difficulty of final interpretation of the data. In order to eliminate artifacts and generally improve the reliability and accuracy of geophysical interpretation, it is useful to perform a joint approach of different geophysical methods, also introducing the a priori information. In this work, it is shown the integrated study of seismic refraction tomography and electrical resistivity tomography techniques, the two geophysical methods are tested on both synthetic and real data and the integration of data is useful in detecting buried cavities and also evaluate their geometric characteristics. Likelihood parameters has been defined and tested, in order to help recognizing voids from other lithological structures. Finally, a statistical approach based on cluster analysis of the P-wave velocity, the density of the seismic rays and the electrical resistivity of the synthetic and experimental models was used. Multi-space cluster distribution maps were built, allowing to better define and interpret the anomalies of the subsoil.

VIAS – the Vienna Institute for Archaeological Science

The Vienna Institute for Archaeological Science (VIAS) was founded within the University of Vienna in 1992 as a forward-looking transdisciplinary institution. VIAS aims to develop and integrate methods from the natural sciences in a dynamic relationship with the culture-oriented investigative frameworks of archaeology, and to provide support, knowledge and partnership in multidisciplinary research programmes and projects. VIAS functions as a core facility and is conducting research in the fields of archaeobotany, archaeozoology, bioarchaeology, archaeometry and archaeometallurgy, analysis of precious metals, ceramology, geophysical archaeological prospection on land and underwater, geoarchaeology, digital archaeological documentation methods, and experimental archaeology. VIAS reaches out beyond the university by developing and collaborating in projects together with the Austrian Academy of Sciences and regional museums and cultural heritage administrations as well as many international partners. VIAS has substantially contributed to the development of efficient high-resolution prospection methods as a founding partner in the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology.