TY - JOUR

T1 - Geoelectrical Anomalies from Hearths and Their Origin

AU - Ermolaev, K. A.

AU - Olenchenko, V. V.

PY - 2024/9/30

Y1 - 2024/9/30

N2 - 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.

AB - 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.

KW - archaeological geophysics

KW - electrical resistivity tomography

KW - hearths

KW - induced polarization

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85205812292&origin=inward&txGid=e8d1b0a2e0aca9567dc498483c8d7c60

UR - https://www.mendeley.com/catalogue/0b45cf1a-36a2-3d56-a95a-e279ae8f3b4a/

U2 - 10.1134/S1069351324700691

DO - 10.1134/S1069351324700691

M3 - Article

VL - 60

SP - 742

EP - 749

JO - Izvestiya, Physics of the Solid Earth

JF - Izvestiya, Physics of the Solid Earth

SN - 1069-3513

IS - 4

ER -