Estimation of the Pb Content in a Tailings Dam Using a Linear Regression Model Based on the Chargeability and Resistivity Values of the Wastes (La Carolina Mining District, Spain)

The study area is located in the old mining district of Linares–La Carolina (southeastern Spain), the largest global producer of lead between 1875 and 1920. The selected environmental liability is the dam of the Federico mine and the waste that was generated during the flotation process. Geophysical techniques were applied along the slope of the dam, specifically ERT and IP. In total, 26 waste samples were taken along the entire slope of the dam, in which a high metal(oid) content was identified, sometimes much higher than the reference levels established by European and regional legislation for contaminated soils. The concentrations of Pb, As, and Ba stood out, with mean values of 4863 mg.kg−1, 89 mg.kg−1, and 794 mg.kg−1, respectively. Univariate and multivariate statistical analysis could characterize the distribution of the contents of the different elements along the slope, defining the associations and dispersion patterns of the metal(oid)s in the interior structure of the mine wastes. With the results of the Pb content (the most abundant metal in mineral paragenesis), a mathematical model was obtained by linear regression that related the variability of this cation with the variation in electrical resistivity and chargeability obtained by geophysical techniques.

Geophysical prospection for late Holocene burials in coastal environments: Possibilities and problems from a pilot study in South Australia

Geophysical techniques have been widely employed for the noninvasive location of burial sites in archaeological and forensic investigations. This approach has met with varying degrees of success, depending on factors such as equipment choice, survey methodology, burial type, and geological setting. This paper reports the results of a multitechnique geophysical survey carried out immediately prior to the salvage excavation of two Indigenous burials from an eolian dune in coastal South Australia. Ground-penetrating radar was not successful in defining the location of the burials owing to the disturbed nature of the local stratigraphy. Magnetic field intensity and apparent magnetic susceptibility surveys identified discrete anomalies that coincided with the location of skeletal material revealed during excavation, which we hypothesize to be due to burning or ochre use during funerary practices. Despite the spatial association of these features, subsequent laboratory analyses of the mineralogy and magnetic properties of sediments collected from the site failed to find a definite cause of the anomalies. Nevertheless, the association between them and the primary interment locations has implications for archaeological surveys carried out in the Australian coastal zone, as it highlights the potential of magnetic field intensity and apparent magnetic susceptibility geophysical techniques undertaken with a more refined survey methodology to afford a noninvasive, culturally appropriate means through which to detect Indigenous burials. This approach may prove particularly useful in areas with disturbed stratigraphy where ground-penetrating radar is less effective.

Trialing geophysical techniques in the identification of open Indigenous sites in Australia: A case study from inland northwest Queensland

The use of geophysical techniques as an aid to archaeological investigations has become common-place, however these methods have only occasionally been applied in Indigenous Australian archaeology. This is despite recognition (and recommendations) since the 1970s that such approaches have the potential to yield positive results in such contexts (e.g. Connah et al. 1976; Stanley 1983; Stanley and Green 1976). Australian archaeologists have perhaps been reluctant to embrace these techniques because of their perceived high cost (both of equipment and specialist staff) and the subtle nature of subsurface Indigenous sites as geophysical targets. Nevertheless, there have been a number of recent applications of these techniques in Australia, particularly in relation to burial and hearth sites. We report the results of a pilot study conducted in northwest Queensland. This study aimed to test the applicability of geophysical methods being routinely employed to locate a variety of open site features (particularly hearths and middens) as part of reconnaissance surveys. While not being entirely successful, this study demonstrated that certain archaeological features can be readily identifi ed using geophysical techniques, though further research and trials should be carried out to refi ne the uses of these techniques to allow their more widespread applicability.

Locating Graves with Geophysics

The detection and mapping of unmarked graves is a significant focus of many archaeological and forensic investigations however traditional methods such as probing, forensic botany, cadaver dogs or dowsing are often ineffective, slow to cover large areas or excessively invasive. Geophysics offers an appealing alternative suitable for the rapid non invasive investigation of large areas. Unfortunately graves are a challenging target with no diagnostic geophysical response and so the use of a rigorous application-specific methodology is essential for a successful outcome. The most important inclusions in a successful survey methodology include ultrahigh density data, the use of multiple geophysical techniques to validate results based on several physical properties, excellent quality positioning and intensive site recording. Regardless of the methodology applied, geophysics should not be considered a panacea for locating all graves on all sites but should be used as an integral part of a comprehensive survey strategy.

Some preliminary notes on the limited 2020 campaign of the Palamas Archaeological Project (PAP)

This paper presents a short summary of archaeological operations carried out in 2020 in the area of the modern village of Vlochos on the western Thessalian plain, Greece, as part of the Palamas Archaeological Project (PAP). Initially, the project aimed to conduct a significant campaign of fieldwork during the 2020 season, but operations were severely scaled back by limitations imposed by the COVID-19 pandemic. Therefore, only a small-scale campaign, aimed at method testing and exploratory investigation, could be carried out. Fieldwork included an evaluation of complimentary geophysical techniques, cleaning operations, and oral history enquiries. The work—despite its limitations—highlighted the value of using multiple geophysical techniques, as well as proving the importance of a systematic cleaning of the site. Overall, the first season of PAP highlighted the productivity of the research project and will act as a strong foundation for the forthcoming field seasons.

Geophysical Delineation of Barite-Galena Mineralization Using Coupled Electrical Resistivity (ER) and Induced Polarization (IP) Techniques. A Case Study of Iyamitet, Cross River State, South-South, Nigeria

A combined Electrical Resistivity (ER) and Induced Polarization (IP) techniques were carried out at Iyamitet, Cross-River State Nigeria with the aim of mapping the Barite-Galena mineralization zone within the area. Five traverses were established in orthogonal directions with length of 100 m. The traverses were established in grid format for better coverage of the study area and Dipole-Dipole electrode configuration was adopted for the data acquisition for both ER and IP. Res2Dinvx software was employed for the joint inversion of the data and the resulting 2D resistivity and chargeability images of the subsurface were interpreted qualitatively and semi-quantitatively to locate the mineralized zone. The result of the investigation revealed that the resistivity values of the suspected mineralized zones fall between 1023 ohm-m to 377599 ohm-m and the chargeability falls between 232 msec and 727 msec. The depth to the top of some of the mineralized zones is as shallow as 1.25 m and as deep as 19.8 m in other places. The results of the investigation have indicated the presence of the Barite-Galena ore within the area and this manifested as high resistivity and high chargeability zones along the traverses. The result of this investigation highlights the efficiency of combined geophysical techniques in locating mineralized zones in a basement area.