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At the research location at PT. Ansaf Inti Resource, there are several mining stages such as exploration. In the exploration itself, drilling and logging activities are carried out. However, if not careful in calculating coal resource estimates, there can be potential discrepancies between the estimated coal resources based on the results of drilling data identification and well logging data with the actual results. Exploration activities are activities that are often carried out by companies to determine reserves in an area. Without carrying out these activities, companies will have difficulty estimating the profits to be obtained. To obtain the data needed to carry out exploration activities such as calculating the quality and quantity of coal, it is necessary to carry out drilling such as the full coring method and also carry out logging activities to complete the data and also as comparative data from core drilling. Coal Resources are part of a coal deposit in the form of a certain quantity and have reasonable prospects that allow for economic consideration. Coal resources are divided according to the level of geological confidence into inferred, indicated, and measured categories. Therefore, in this study, the author will calculate coal resources from exploration data collection such as coring data, cutting data, and well logging data as well as coal quality data and process it in Minescape 5.7 software so that it can obtain an estimate of coal resources for each seam at the research location.

Travertine is a non-marine carbonate rock precipitated from calcium- and bicarbonate-rich waters, commonly associated with hot springs, streams, and lakes in tectonically active regions. This study presents a systematic literature review of travertine deposit characteristics, encompassing mineralogical composition, geochemical signatures, petrographic textures, morphological types, isotopic properties, biotic–abiotic controls on formation, early diagenesis, and petrophysical implications. The synthesis indicates that travertine is predominantly composed of calcite, with aragonite forming under conditions of elevated temperature, high Mg/Ca ratios, and rapid CO₂ degassing. Travertines display exceptional textural diversity, ranging from abiotic crystalline crusts to microbially mediated fabrics such as shrub, peloidal, and stromatolitic structures. Major morphologies include fissure ridges, mounds, terraces, cascades, and slopes, strongly governed by tectonic setting, topography, hydrology, and substrate geology. Stable isotopes (δ¹³C and δ¹⁸O), strontium isotopes, trace elements, and REE patterns effectively constrain fluid provenance and distinguish thermogene from meteogene travertines. Microbial activity plays a crucial role in biomineralization, influencing precipitation rates, crystal morphology, and lamination patterns. Early diagenetic processes occurring during active deposition may significantly modify primary fabrics and geochemical signals. Travertine petrophysical properties exhibit distinctive porosity–velocity relationships, making them valuable analogues for subsurface carbonate reservoirs. This review highlights that travertines record complex interactions among physical, chemical, biological, and geological processes and hold significant value for paleoenvironmental reconstruction and carbonate reservoir studies.

Blasting is a critical method for overburden removal in open-pit coal mines, where fragmentation quality directly impacts loading efficiency and operational costs. This study aims to analyze the actual fragmentation resulting from overburden blasting at Pit 4 Middle of PT. Victor Dua Tiga Mega, Central Kalimantan, to predict fragmentation using the Kuz-Ram model, and to evaluate the conformity of both results against the company standard (boulder size ≤144.6 cm or ≥50 cm for analysis). The research employed a quantitative comparative method. Primary data included blasting geometry and photographs of muck piles from 10 blasting events, which were analyzed using WipFrag software to obtain actual fragmentation distribution. Secondary data comprised rock characteristics and explosive properties for Kuz-Ram prediction input. The results showed significant variation in actual boulder percentage (≥50 cm), ranging from 6.19% to 32.91% with an average of 16.05% (medium category). Statistical analysis revealed a very weak negative correlation (r = -0.21) between powder factor (PF) and boulder percentage, indicating that PF is not the dominant factor within the consistent application range (0.21-0.23 kg/bcm). Comparison with Kuz-Ram predictions showed that the model consistently over-predicted coarse material, with an average difference of +25.21%, suggesting the need for rock factor (A) recalibration. It is concluded that the blasting results are inconsistent, strongly influenced by uncontrollable factors such as geological conditions. Recommendations include geometri evaluation, particularly burden and spacing, and calibration of the Kuz-Ram model for more accurate future predictions.

Facies analysis and thin-section petrography are complementary and essential approaches for determining the lithological characteristics of deep-water deposits. Deep-water sediments are formed by diverse depositional processes such as turbidity currents, debris flows, slumps, and pelagic suspension settling, producing a wide range of lithofacies with distinctive textural, compositional, and sedimentary structural attributes. This literature review synthesizes studies that apply facies analysis and thin-section petrography to characterize deep-water deposits across various basins and geological ages worldwide. Field-based facies analysis emphasizes lithology, sedimentary structures, bed geometry, and vertical–lateral facies relationships to reconstruct depositional environments. In contrast, thin-section petrography provides microscopic insights into mineral composition, grain texture, cement types, porosity, and diagenetic features that are not observable in the field. The integration of these methods, often combined with advanced techniques such as XRD, SEM, and geochemical analyses, has proven effective in distinguishing lithofacies, understanding sedimentary processes, and evaluating reservoir quality. The review highlights that grain size, sorting, cement type, pore-throat size, and diagenetic processes are key controls on lithological characteristics and reservoir potential in deep-water systems. Therefore, the combined application of facies analysis and thin-section petrography provides a comprehensive framework for interpreting deep-water sedimentary systems.

This study aims to reflect on the theological meaning of natural disasters in Sumatra (Aceh, Simeulue, Padang) from an ecological perspective. Although Sumatra is geologically prone to earthquakes and tectonic activities due to its location on the Pacific Ring of Fire, hydrometeorological disasters such as floods and landslides are exacerbated by human actions, including deforestation, watershed degradation, and uncontrolled land conversion. This research employs a qualitative-descriptive approach using library research and a theological-reflective method. Primary sources include Sacred Scripture, Church documents (Laudato Si', Gaudium et Spes, General Directory for Catechesis), and relevant ecological theology literature. The findings indicate that natural disasters in Sumatra can be interpreted as "signs of the times" revealing both ecological and moral crises. Disasters are not divine punishment but consequences of humanity's misuse of freedom in managing creation. Ecological conversion is urgently needed at personal, social, and structural levels. Within the catechetical framework, disaster experiences become "texts of life" that guide the faithful toward mature faith expressed in lifestyle changes, solidarity, and responsibility for our common home.

Landslides in the Giritengah Catchment Area are influenced by several factors, including geological conditions, rainfall intensity, geomorphology, soil characteristics, and inappropriate land use practices, all of which affect regional spatial planning and environmental stability. This study presents a literature review that analyzes landslide vulnerability, evaluates the impact of land use changes, and proposes integrated Soil and Water Conservation Techniques (SWCT) to support sustainable land management. The analysis applies Geographic Information System methods using thematic map overlays such as rainfall distribution, slope gradient, geological structure, and land use patterns. The results show that areas categorized as having high landslide vulnerability cover 44.02% or approximately 158.69 hectares of the catchment area, while areas with very low vulnerability account for only 0.12% or about 0.79 hectares. Land use conversion, particularly mixed dryland agriculture, has increased landslide risk by reducing slope stability and increasing surface runoff. To address this issue, conservation strategies are recommended, including vegetative measures such as greening 38.51 hectares in settlement areas and implementing agroforestry systems across 218.48 hectares. In addition, structural measures such as three dam retainers and twenty gully plugs are proposed in both protected and cultivation zones to support disaster mitigation and align with regional spatial planning policies.

This study aims to evaluate the actual sump capacity in accommodating mine water discharge, design a sump that fits field conditions, and determine the optimal pump capacity and system at PT Satria Alam Manunggal, Telen Orbit Prima Site. The research methods include field data collection (sump condition, water discharge, and pump capacity) and supporting data (rainfall, geological maps, and pump specifications). The design rainfall was calculated using the Gumbel method with a five-year return period, while water discharge was estimated from runoff, rainfall, and groundwater inflow. The results indicate that the existing sump, with a capacity of 508 m³, is insufficient to accommodate an inflow of 1.210 m³/s. Therefore, two new sumps were designed: the West Sump with a capacity of 38,400 m³ and the East Sump with 78,281 m³. Each sump employs a DnD 150-4H pump with a discharge rate of 480 m³/hour. The West Sump pump can drain water within approximately three days, while the East Sump requires about seven days. The trapezoidal sump design was chosen for its efficiency, structural stability, and effectiveness in sediment (TSS) deposition control, maintaining levels within safe limits. In conclusion, the design of the West and East sumps is considered optimal in accommodating mine water discharge and improving the overall effectiveness of the mine drainage system.

Guaranteeing the geotechnical stability of slopes is an absolute prerequisite for the sustainability of open pit mining operations, considering the potential for multidimensional losses due to slope failure. The specific geological conditions at PIT B1 PT. Pancaran Surya Abadi, which is composed of sedimentary rocks (coal, sandstone, and claystone), are susceptible to degradation and softening, especially due to high rainfall that causes an increase in pore water pressure and a decrease in rock shear strength. This study aims to analyze the stability of highwall slopes using the Morgenstern-Price Method to determine the Safety Factor (SFF) value according to Ministerial Decree number 1827 K/30/MEM/2018, and continued with a semi-quantitative risk analysis. The analysis results show that the initial slope has a static SFF of 0.77 (Not Safe). After redesign, the recommended optimal single slope geometry is: sandstone (Height 5 m, Angle 20°, Berm 5 m) and claystone (Height 10 m, Angle 60°, Berm 5 m). This redesign resulted in a FK of 1.34 (Safe). Sensitivity analysis to groundwater level rise (GTL) showed that the GTL value remained safe (GTL ≥1.30) up to a 30% increase in GTL. However, a 40% to 80% increase in GTL caused the GTL to decrease (1.28–1.21), classified as Medium Risk. A 100% increase in GTL drastically reduced the GTL to 1.05, classified as High Risk. This study emphasizes the need for close monitoring and additional drainage to maintain the long-term stability of slopes under the influence of rainfall.