{"title":"Geoelectrical Anomalies from Hearths and Their Origin","authors":"K. A. Ermolaev, V. V. Olenchenko","doi":"10.1134/S1069351324700691","DOIUrl":null,"url":null,"abstract":"<p><b>Abstract</b><i>—</i>The paper discusses anomalies that are observed in the electric fields above hearth deposits. Hearths are important objects for archaeological studies and are traditionally detected by the positive anomaly in magnetic induction. However, magnetic measurements are not available on every archaeological site, and burning sites are not the only sources of positive magnetic anomalies. In the 1960s, it was established that the hearths can be detected using the induced polarization method (IP), but the technique has not been developed because of the imperfection of equipment at that time. Currently, multi-electrode multichannel electromagnetic prospecting systems allow prompt assessment of the distribution of electrical properties of the object and reconstructruction of its three-dimensional geoelectric structure. In this study, we examined geoelectric anomalies from a hearth, elucidated their nature, and evaluated the possibility of using electrical resistivity tomography (ERT) method to search for such objects. By the example of the fieldwork and laboratory experiments it is shown that hearths create intense anomaly of induced polarization and are distinguished by a very low electrical resistivities. It is established that the boundaries of the burning sites are clearly expressed in the maps of normalized chargeability. To study the nature of the observed geoelectrical anomalies, we carried out X-ray phase analysis and measurements of induced polarization, electrical resistivity, and magnetic susceptibility. The results have shown that the anomaly of low electrical resistivity and the polarizability anomaly are caused by the presence in hearth material of X-ray amorphous carbon in the form of soot, but not magnetite. Application of electrical resistivity tomography combind with induced polarization measurements is recommended in the search for fireplaces in archaeological prospecting.</p>","PeriodicalId":602,"journal":{"name":"Izvestiya, Physics of the Solid Earth","volume":"60 4","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Izvestiya, Physics of the Solid Earth","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1134/S1069351324700691","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract—The paper discusses anomalies that are observed in the electric fields above hearth deposits. Hearths are important objects for archaeological studies and are traditionally detected by the positive anomaly in magnetic induction. However, magnetic measurements are not available on every archaeological site, and burning sites are not the only sources of positive magnetic anomalies. In the 1960s, it was established that the hearths can be detected using the induced polarization method (IP), but the technique has not been developed because of the imperfection of equipment at that time. Currently, multi-electrode multichannel electromagnetic prospecting systems allow prompt assessment of the distribution of electrical properties of the object and reconstructruction of its three-dimensional geoelectric structure. In this study, we examined geoelectric anomalies from a hearth, elucidated their nature, and evaluated the possibility of using electrical resistivity tomography (ERT) method to search for such objects. By the example of the fieldwork and laboratory experiments it is shown that hearths create intense anomaly of induced polarization and are distinguished by a very low electrical resistivities. It is established that the boundaries of the burning sites are clearly expressed in the maps of normalized chargeability. To study the nature of the observed geoelectrical anomalies, we carried out X-ray phase analysis and measurements of induced polarization, electrical resistivity, and magnetic susceptibility. The results have shown that the anomaly of low electrical resistivity and the polarizability anomaly are caused by the presence in hearth material of X-ray amorphous carbon in the form of soot, but not magnetite. Application of electrical resistivity tomography combind with induced polarization measurements is recommended in the search for fireplaces in archaeological prospecting.
摘要--本文讨论了在炉床上方电场中观察到的异常现象。炉膛是考古研究的重要对象,传统上是通过磁感应正异常来探测的。然而,并非每个考古遗址都能进行磁场测量,而且焚烧遗址也不是正磁场异常的唯一来源。20 世纪 60 年代,已经确定可以使用感应极化法(IP)探测炉膛,但由于当时的设备不完善,该技术一直没有得到发展。目前,多电极多通道电磁勘探系统可以迅速评估物体的电特性分布,并重建其三维地电结构。在本研究中,我们研究了一个炉膛的地电异常,阐明了其性质,并评估了使用电阻率层析成像法(ERT)搜索此类物体的可能性。通过实地考察和实验室实验的实例表明,炉坑会产生强烈的感应极化异常,并以极低的电阻率加以区分。通过归一化电荷率图可以清楚地看出燃烧点的边界。为了研究观测到的地质电异常的性质,我们进行了 X 射线相分析以及感应极化、电阻率和磁感应强度的测量。结果表明,低电阻率异常和极化率异常是由于炉床材料中存在烟尘形式的 X 射线无定形碳,而不是磁铁矿造成的。建议在考古勘探中应用电阻率层析成像与感应极化测量相结合的方法寻找壁炉。
期刊介绍:
Izvestiya, Physics of the Solid Earth is an international peer reviewed journal that publishes results of original theoretical and experimental research in relevant areas of the physics of the Earth''s interior and applied geophysics. The journal welcomes manuscripts from all countries in the English or Russian language.