Structural geology analysis using Electrical Resistivity Imaging (ERI) In Felda Chiku 5, Paloh, Gua Musang, Kelantan.

INTEGRATED METHODS USING MULTICHANNEL ANALYSIS OF SURFACE WAVES (MASW) AND ELECTRICAL RESISTIVITY TOMOGRAPHY (ERT) FOR GEOTECHNICAL HAZARD ASSESSMENT (A Case Study of Queen Ede, Benin City, Edo State)

Gully erosion has been among the most serious environmental and geotechnical risks within the southeastern part of Nigeria, which endangers infrastructure, livelihood, and sustainable land use. This paper discusses the use of an integrated geophysical technique that consists of Electrical Resistivity Tomography (ERT) and Multichannel Analysis of Surface Waves (MASW) to study the Queen Ede gully site in Benin City, Edo State. ERT was used to describe the subsurface changes in resistivity and MASW was used to give the profile on shear-wave velocity and soil stiffness. The findings indicate that there are major lateral and vertical differences in underground materials. Areas of high resistivity are associated with sandy and erosion-prone soils and low resistivity areas are associated with clay-bearing sediments, which, while more cohesive, become vulnerable to undercutting once overlying sandy units are eroded. A type of analysis using MASW revealed that the changes in stiffness were between very soft and stiff soils with shallow weak zones directly correlated to the regions of active erosion and slope instability. This combination of MASW and ERT leads to the identification of areas of increased vulnerability, which supports the idea that the use of single methods would have given incomplete results. The given study proves that combined near-surface geophysical methods can provide an efficient and rather economical instrument of geotechnical hazard assessment in the erosion-prone areas. The results furnish essential data in the urban planning, infrastructure planning and erosion control strategies, and provide a methodological framework to be used in other sites of gully erosions in Nigeria and other regions.

Groundwater Identification Using the Geoelectric Method (Electrical Resistivity Tomography/ERT) For the Utilization of Mining Areas

Geoelectrical Resistivity for Delineating Slip Surfaces in Landslide Areas: A Case Research from Selopamioro, Bantul, Indonesia

Landslides are a common natural disaster in Indonesia, particularly in areas with steep slopes and high rainfall intensity. They can cause significant damage to property, loss of life, and disrupt the daily lives of affected communities. Bantul Regency is especially susceptible to landslides due to its geological structure and the tectonic activity resulting from the convergence of three major tectonic plates in the region. This research aimed to identify subsurface lithology and slip surface in the landslide-prone area of Selopamioro Village, Imogiri District, Bantul Regency, using the Wenner configuration resistivity geophysical method. Four measurement lines were conducted, each with a length of 225–240 meters and an electrode spacing of 15 meters. Data processing was performed using the Res2Dinv application to produce a two-dimensional resistivity model and RockWorks 17 for three-dimensional visualization. The modeling results revealed resistivity values ranging from 0.11 to 779 Ω·m, which were classified as sandy clay (0.11–44 Ω·m) and breccia (>44 Ω·m). The low resistivity zone indicated the presence of a wet sandy clay layer. The slip surface is estimated to be located at a depth of 20–30 meters below the surface, marked by a resistivity contrast boundary between the sandy clay layer and the fractured breccia. Local geological conditions, including volcanic breccia, rock fractures, and high rainfall infiltration, exacerbate the potential for slope instability.

Structural Control and Evaluation of the Geothermal System in Seulawah Agam, Aceh: A Geological and Geophysical Approach Using Fault Fracture Density, Land Surface Temperature, and Gravity Data

Seulawah Agam, located in Aceh Province, is a Quaternary stratovolcano with notable geothermal manifestations, making it a promising target for renewable energy exploration. This study aims to evaluate the geothermal system and its structural controls through an integrated geological and geophysical approach. Geologically, Fault Fracture Density derived from remote sensing data is used to identify major fault zones, ridgelines, and structural trends that may act as conduits for geothermal fluid migration. Land Surface Temperature (LST) data from thermal infrared satellite imagery are employed to detect surface thermal anomalies indicative of subsurface geothermal activity. Geophysically, gravity data processed into Complete Bouguer Anomaly (CBA) and derivative maps are used to delineate subsurface structures, density contrasts, and potential heat sources. The study area covers approximately 17 × 16 km, with Bouguer anomaly values ranging from a minimum of 394.74 mGal to a maximum of 614.23 mGal. The integration of these datasets allows for the correlation between surface features and deeper geothermal reservoirs, highlighting structurally controlled zones with elevated geothermal potential. Preliminary findings indicate that NE-SW and NW-SE trending lineaments intersect with thermal anomalies and gravity lows, suggesting the presence of deep-seated fractures and fault zones associated with heat migration pathways. The study emphasizes the importance of structural mapping and geophysical validation in assessing geothermal viability. This integrated approach provides a robust foundation for future exploration efforts in Seulawah Agam and supports Indonesia’s broader goals for sustainable and renewable energy development in tectonically active regions.

Subsurface Lithostratigraphic Characterization Using Integrated Log and Cross-Plot Analysis: Re-evaluation of a Borehole in Chirirbandar, Dinajpur, Bangladesh

This research represents a detailed Litho-stratigraphic characterization of Precambrian basement complex by integrating geophysical log and drilling data of GDH-76 from technical reports of the Geological Survey of Bangladesh (GSB). It is a re-evaluation of a Borehole data by interpreting drilling parameter and interval-averaged geophysical log data. A high-resolution petro-physical “fingerprint” of the Northwestern Bangladesh basement complex is identified by integrated cross-plot analysis. This study delineates a six subsurface zones by correlated Rate of Penetration (ROP), Percentage of Core Recovery, Magnetic Susceptibility, Gamma-Resistivity signatures. The Result shows a distinct 6 meter weathered transition zone (200-206 m) characterized by low core recovery (45%) and moderate ROP (1.02 m/hr). The basement entry at 206 m is marked by moderate to high (0.46 to 1.1 m/hr) in ROP and moderate resistivity (72.5 ohm-m) indicating weathered condition. Notable feature include a 15-meter thick magnetic anomaly zone (295-310 m), identified with a peak susceptibility of 1130 cgs unit, suggesting a mineralization zone. Moreover, a high-gamma unit (318-336 m) exhibiting a value of 375 cps (peak value) with extremely low ROP (0.132 m/hr) indicates a high strength potassium-rich felsic lithology. Furthermore, the research also pinpointed the F39 fault boundary between two boreholes.

Identification of Weak Zones with Resistivity Values Using Electrical Resistivity Imaging in Bentiring Subdistrict, Bengkulu