Integrating Surface Geological Mapping and Multi-Year Subsurface Data to Identify Lateral Lithological Variations Along the Jatinegara Diversion Tunnel, Central Java, Indonesia
Tunnel design in tropical regions requires careful attention to subsurface variability due to intense weathering and complex lithology. The ongoing design of the Jatinegara Diversion Tunnel, with a diameter of 6 meters and a length of 439 meters, relies solely on the 2024 borehole data without considering the recent 2017 data, revealing a contrast subsurface geological characteristic. This study investigates lateral lithological variations along the tunnel alignment by integrating surface geological mapping with multi-year borehole data from 2017 and 2024. The methodology includes geological mapping of a 2.0 × 2.0 km area, corebox analysis, surface-subsurface stratigraphic correlation, and rock mass quality evaluation using the Rock Mass Rating (RMR) system. Results show the tunnel traverses five zones with distinct rock mass characteristics. Zone 1, Zone 3, and Zone 5 consist of andesitic breccia with RMR values ranging from 20.21 – 39.57, indicating poor quality of rock mass. Zone 2 comprises interbedded carbonate sandstone and siltstone overlain by andesitic breccia, with RMR values ranging from 42.82 – 52.40 (fair). Zone 4 consists of interbedded carbonate sandstone and siltstone overlain by massive sandstone with siltstone intercalation with an RMR of 52.43 (fair). Given these rock mass conditions, the recommended excavation method is a top heading and bench approach with 1.0–1.5 meters advance in the top heading with support system consist of rock bolt, shotcrete, and steel set. These findings highlight the importance of integrating multi-year geotechnical data to support an adaptive and safe tunnel design in complex geological environments.
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.
Nazmun Nahar, Mst Monira, M. Reza et al.· Earth Sciences· 0 citations
To address the growing challenges of water resource management in coastal karst areas, this study investigated subsurface lithological characteristics and evaluated aquifer potential in Mon Ikeun Village, Aceh Besar. The research integrated Electrical Resistivity Tomography (ERT) and grain size gradation analysis to provide a scientific basis for sustainable groundwater exploration. Resistivity data were collected along three survey lines, each 420 m long, using the Wenner-Schlumberger configuration. The 2D inversion results identified conductive zones with resistivity values below 454 Ωm, interpreted as alluvium comprising sand, silt, and gravel. These high-porosity, permeable layers extend to depths of approximately 25 m, indicating significant aquifer potential. In contrast, resistive zones above 454 Ωm were interpreted as limestone bedrock, representing impermeable layers with very low porosity. Laboratory grain size analysis using the hydrometer method revealed sand-dominated samples with high porosity (25-50%) and moderate permeability (2.5-45 m/day), while gravel-sand mixtures displayed moderate porosity (25-40%) and high permeability (150-450 m/day). The strong correlation between resistivity data and grain size distribution confirms the consistency of the lithological interpretation. This integrated approach offers an effective framework for securing freshwater resources in regions with complex geological settings and high vulnerability to water scarcity.
Muhammad Syukri, Adila Latifa, D. Sugiyanto et al.· IOP Conference Series: Earth...· 0 citations
Seismic attributes are widely used to enhance geological interpretation by extracting quantitative information from seismic data. They provide insights into both structural and stratigraphic features, enabling interpreters to detect subtle changes in lithology, continuity, and geometry of subsurface formations. Attributes are especially useful in improving the resolution of seismic images, helping to delineate horizons, identify fault patterns, and visualize depositional features. This study focuses on using seismic attribute analysis to clarify the distribution of sand bodies within a reservoir interval. The objective is to identify zones with favourable sand development, define their geometry and connectivity, and outline areas with high hydrocarbon reservoir potential. The interpreted I Sequence was divided into three sub-sequences, each modelled with a geological grid size of 50m×50 m and subdivided into 150 layers. The porosity model showed mean values ranging from 0.228 to 0.2484 across the main reservoir zones, while water saturation varied from 0.90659 to 0.92747. After calculating seismic attributes, the authors delineated sand bodies in the I38_upper layer located in the North–Northwest, Northeast, and smaller bodies in the South. In the I90 layer, sand bodies were identified in the North–Northeast, East, and Southeast, along with narrow, laterally restricted sands in the western part of the study area. The P2 reserve with 50% confidence for the most potential interval (I23–I38) was estimated at 86 million cubic meters after running 200 cases.
Duong Quoc Phong, Truong Minh Ngoc Quy, Nguyen Trong Dai et al.· IOP Conference Series: Earth...· 0 citations
Abstract A geothermal potential assessment was conducted in the Suban Curup–Rejang Lebong Hot Spring Area, Bengkulu Province, Indonesia. This study aimed to identify subsurface geological structures—faults, volcanic features, and sedimentary layering—that may control the development of geothermal reservoirs and caprock units. Two complementary geophysical approaches were integrated: (1) Three-dimensional (3-D) inversion modeling of Bouguer gravity anomalies derived from Global Gravity Model plus (GGMplus) 2013 and corrected using SRTM2gravity at 1,937 measurement points, and (2) microtremor acquisition at 106 sites with 60-minute recording duration, processed using the Horizontal-to-Vertical Spectral Ratio (HVSR) method. The residual gravity inversion results reveal density contrasts of 2.40–3.40 g/cm3 and sediment thicknesses exceeding 80 m, interpreted as potential geothermal reservoir units. These findings are consistent with the HVSR results, which show moderate to high amplification (A0 = 3–9) and natural frequencies of 1–10 Hz, indicating porous and fractured formations favorable for fluid storage. Overall, the integration of satellite gravity and microtremor data highlights the presence of thick sedimentary deposits and structurally controlled pathways, suggestive of promising geothermal reservoir targets in the Suban Curup area.
P. K. Putri, Ahmad Fauzi Pohan, A. M. Lubis et al.· Civil and Environmental Engi...· 0 citations
The Maduky Field, situated within the Coastal Swamp depobelt of the Niger Delta Basin, represents a structurally complex and geologically heterogeneous marginal field with untapped hydrocarbon potential. This study integrates 3D seismic interpretation, well log correlation, sequence stratigraphy, and petrophysical analysis to characterize its reservoir architecture and evaluate hydrocarbon volumes. Structural mapping reveals prominent listric growth faults and rollover anticlines that define three main field compartments, each with distinct depositional and trapping characteristics.
Sequence stratigraphic analysis, guided by five regionally correlated Maximum Flooding Surfaces (MFSs), delineates Genetic Sequences and system tracts (HST, TST, LST), each with unique parasequence stacking patterns and reservoir geometries. The highstand and lowstand system tracts host the most prolific reservoirs, characterized by clean, coarsening-upward sand bodies with high net-to-gross ratios and favorable porosity-permeability relationships. Petrophysical evaluation across five wells indicates effective porosity values of 20–34%, permeability ranging from 2.50 to 18 mD, and low water saturation (8–35%), confirming reservoir quality suitable for commercial exploitation. Crossplots further demonstrate the controls of porosity and depositional environment on fluid distribution and reservoir performance.
The study identifies key hydrocarbon-bearing units sealed by marine shales associated with MFSs and quantifies Stock Tank Oil Initially In Place (STOIIP) across fault blocks, highlighting potential development zones. These insights support the redevelopment of Maduky Field and provide a scalable model for optimizing marginal field performance in mature deltaic basins.
S. Onyekuru, Reginald Chinonso Maduka, T. C. Anyanwu et al.· Romanian Journal of Petroleu...· 0 citations
Semi-arid regions are often characterized by strong spatial heterogeneity of geological formations, surface processes, and groundwater circulation, which critically control water availability and land use planning. This study investigates the subsurface structure of the Wadi Zouzfana basin (south-western Algeria) using an integrated approach combining vertical electrical sounding (VES) and lithological data from three core boreholes (21-30 m depth). Twenty-four VES measurements were conducted using the Schlumberger configuration (= 200 m) and calibrated against borehole logs to establish reliable resistivity-lithology relationships in a karstified carbonate environment. Five main geoelectrical units were identified, corresponding to recent alluvium, karstified limestone, transitional carbonates, weathered dolomite, and compact bedrock. Low resistivity values (100-600 Ω•m) dominate the wadi axis, reflecting water-saturated alluvial deposits and karstified limestone, while higher resistivities (>1200 Ω•m) characterize structurally uplifted carbonate formations along the basin margins. Spatial interpolation of resistivity data within a GIS frame-work reveals an asymmetric bedrock morphology controlled by NE-SW tectonic structures, with a central depression guiding surface runoff concentration and groundwater storage. The results highlight the strong geomorphological and structural control on groundwater distribution and infiltration potential in this semi-arid karst basin. The integrated geophysical-lithological methodology provides a cost-effective framework for site-scale subsurface characterization applicable to similar semi-arid karst environments and supports sustainable water resource management and land planning in data-scarce arid environments.
S. Samai, L. Benhenni, Leila Bouchama· Glasnik Srpskog Geografskog...· 0 citations