Applying Electrical Resistivity Tomography in Ornamental Stone Mining: Challenges and Solutions

Abstract

In this study, the use of electrical resistivity tomography (ERT) as a tool to guide ornamental stone extraction is investigated. ERT is not conventionally used in highly resistive environments, such as on rock faces, due to the high contact resistances that can impede current injection. Here, the challenges of conducting ERT in such environments are discussed and possible solutions suggested. For this, an example of the application of ERT in a deep and narrow marble quarry is used. The marble deposit is affected by fracturing and karstification. Due to the nature of these features, they present a significant resistivity contrast to the background resistivity of the marble and thus excellent targets to test the application of ERT. Their location was mapped using field observations and complementary ground penetrating radar data. By using an appropriate sensor deployment, a suitable resistivity meter, and advanced data processing routines, the derived 3D resistivity model is in good agreement with the independent observations. This shows that despite the challenges, ERT can be used as a non-invasive tool to obtain information on the stone properties prior to extraction. This will help in guiding quarry operations and will allow for a targeted, safe and efficient extraction of high quality stone, thereby increasing sustainability and economical competitiveness.

Setor produtivo de rochas ornamentais: uma revisão sistemática da literatura

“…Segundo os resultados apresentados pelos autores, os mesmos revelam que o GPR pode ser considerado como um dispositivo exitoso na otimização da recuperação de blocos fragmentados. Uhlemann et al (2018) investigam a aplicação da tomografia de resistência elétrica denominada como (TRE) na mineração de rochas ornamentais, como ferramenta para orientação da atividade extrativa, tendo como local de estudo uma pedreira de mármore dolomítico a céu aberto, localizada na região da Lombardia, Itália. Os autores concluem que ainda que a aplicação da tomografia de resistência elétrica não seja comumente empregada em ambientes eminentemente resistivos como as rochas, a TER pode ser utilizada como mecanismo não invasivo para o alcance de informações sobre as características do cálculo antes da extração, resultando em uma atividade extrativa orientada, efetiva e apropriada, vislumbrando-se um material de elevada qualidade, sustentabilidade e competitividade econômica.…”

Analytical Models and Laboratory Measurements to Explore the Potential of GPR for Quality Control of Marble Block Repair through Resin Injections

“…Geophysical surveys have always played an important role in different projects that concern natural resources. Wherever high contrasts in the physical properties of the target and its hosting medium are expected, proper geophysical techniques can be successfully applied to provide valuable information about the subsurface conditions, e.g., [7][8][9][10][11][12][13][14][15][16][17][18]. Among different geophysical techniques, the ground penetrating radar (GPR) method can provide high-resolution results in a variety of applications, e.g., [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33].…”

The Utilisation of Electrical Resistivity Imaging (ERI) for Geological Structures Mapping in Rock Mass: A Review

“…Besides that, the geophysical method is also used due to its non-invasive and non-destructive technologies, affordable price, rapid result, and compatibility with various materials in the subsurface [8]. The electrical resistivity method is widely used worldwide due to its non-invasive method and ability to cover extensive data [9] quickly. The electrical resistivity method is one of the in-situ geophysical methods that can measure physical features associated with lithological, hydrological, and geotechnical directly or indirectly [10].…”