Mohamed Faisal

Well-trajectory optimization is frequently framed as maximizing reservoir contact, although additional contact does not necessarily enlarge the dynamically connected drainage volume. Here, vertical, J-shaped and horizontal trajectories were evaluated at three locations in the Upper Safa reservoir (Middle Jurassic Khatatba Formation), Western Desert, Egypt, using a controlled Petrel–ECLIPSE workflow that combines simulated cumulative reservoir response with relative drilling complexity under a consistent reservoir model realization. For every location, the reservoir realization, target interval, and operating constraints were held constant, and only the well path and completed grid cells were varied. The resulting nine cases were compared using modeled contact length, early productivity index, cumulative oil and gas recovery, and an authorization for expenditure (AFE)-based relative drilling cost index, used as a decision support indicator rather than a full economic evaluation. Within these single realization cases, the trajectory ranking was location-specific: vertical at SE-1X (1.92 MMSTB oil, 8.6 BSCF gas), J-shaped at SW-1X (1.78 MMSTB, 8.2 BSCF) and horizontal at SE-5 (1.55 MMSTB, 8.7 BSCF). The SE-1X and SW-1X selections were supported by implemented well geometries and production test observations, whereas the SE-5 horizontal case remains a simulation-based outcome because it was not field-implemented. The horizontal cases returned the highest early productivity index at every location but the highest cumulative recovery only at SE-5, indicating that geometric exposure alone was not sufficient to predict cumulative recovery. Directional surveys and discrete production tests for the two implemented wells were consistent with the selected simulation cases (oil-rate MAPE 7.0–7.9%; gas-rate MAPE 2.3–4.9%). Overall, cumulative response, interpreted together with reservoir quality and connectivity diagnostics, provided a more informative basis for trajectory optimization than geometric contact length alone.

Purpose. This study develops a reproducible, precision-first framework for targeting gold mineralization in arid environments, addressing both bedrock and placer deposits at the Wadi Umm Eish El-Zarqa area in Egypt, the first such investigation in this region. Methods. The methodology combines machine learning applied to hyperspectral EnMAP data and spatial geomorphometric analysis of ALOS-PALSAR DEM. Random Forest and Support Vector Machine with Radial Basis Function models were trained on pixel spectra from three known gold mining sites. A spectral probability tolerance of 0.05 was implemented to expand the training dataset. Drainage networks were extracted from DEM data to link upstream bedrock sources to potential downstream placer deposits. ASTER-derived alteration maps were generated for comparative assessment. Findings. Ground-truth validation of the delineated mineralization targets showed SVM-RBF achieved slightly higher overall accuracy (91.8 vs 89.9%), RF delivered perfect precision in identifying mineralized targets, and crucially delineated 37% more high-confidence (> 80% probability) potentially mineralized targets than SVM-RBF. Drainage analysis identified 3rd to 5th-order streams as optimal zones for placer deposition. Fieldwork confirmed active artisanal excavations, with stream sediments reportedly yielding 25-30 grams per truckload (~85 tons). Originality. This study addresses a clear gap in hyperspectral investigations for mineral exploration in the Eastern Desert of Egypt. It is the first study to integrate machine learning with EnMAP hyperspectral data to target placer gold deposits in this region, establishing a precision-focused exploration approach. Practical implications. The framework provides a transferable methodology for mineral exploration in analogous arid terrains worldwide, reducing financial risk and enabling efficient allocation of follow-up resources.

The Guangning district in western Guangdong Province hosts structurally controlled gold deposits associated with long‐lived granitic magmatism from the early Palaeozoic to the late Mesozoic. However, the metallogenic significance of these magmatic episodes remains debated. This study integrates zircon U–Pb geochronology, morphological analysis, trace element geochemistry and Ti‐in‐zircon thermometry for early Palaeozoic granodiorite, early Mesozoic monzogranite and late Mesozoic biotite granite to constrain the temporal evolution of magmatism and its relationship to gold mineralization. Zircon U–Pb dating identifies three distinct magmatic–hydrothermal episodes at ~453–448 Ma (early Palaeozoic), ~249–247 Ma (Triassic) and ~93 Ma (Cretaceous). Early Palaeozoic zircons are dominantly euhedral and oscillatory zoned, consistent with typical magmatic crystallization and suggesting an important role in crustal preconditioning and possible metal pre‐enrichment. Triassic zircons commonly show rounded to resorbed morphologies, dark cathodoluminescence, low Th/U ratios (< 0.16) and strong Eu depletion (0.0001–0.19), indicating highly evolved magmas and intense late magmatic fluid interaction. Combined with published petrogeochemical, structural and isotopic constraints, these features identify the Triassic magmatic event as the principal stage of gold mineralization in the Guangning district. Cretaceous zircons (avg. ΣREE = 820 ppm, Ce/Ce* = 39.68, Eu/Eu* = 0.16) record a younger, comparatively oxidized magmatic episode that caused thermal‐fluid overprinting, remobilization and local upgrading of pre‐existing mineralization. These results suggest that gold mineralization in the Guangning district was not the product of a single magmatic event, but was controlled by multi‐stage magmatic–hydrothermal processes, with the Triassic event representing the dominant metallogenic episode. This study demonstrates the effectiveness of multi‐parameter zircon analysis in resolving complex, multi‐stage granitoid‐related gold mineralization processes.

The Tieshilong Pb-Zn polymetallic district is located along the northern margin of the Dongpo ore field in the middle section of the Nanling metallogenic belt, southern Hunan, China. It represents a typical granite-related, fault-controlled hydrothermal vein-type lead–zinc polymetallic deposit in southern Hunan. In recent years, large-scale tin mineralization has been newly discovered during exploration in the deeper and peripheral areas of the district. However, the timing and genetic nature of this tin mineralization remain undetermined, which limits understanding of the characteristics of the deposit’s metallogenic system and its deep exploration potential. In this study, we present in situ cassiterite U–Pb geochronology and trace element data from deep Pb-Zn-Sn orebodies in the Tieshilong mining district. LA-ICP-MS U-Pb analyses of cassiterite yield a Tera–Wasserburg lower-intercept age of 159.2 ± 6.2 Ma (MSWD = 1.4), indicating that Sn mineralization occurred during the Late Jurassic. This age overlaps, within uncertainty, with the main ca. 160~150 Ma W–Sn metallogenic event recognized throughout the Nanling belt. Trace element data reveal that Tieshilong cassiterite is enriched in Fe (1100–5800 ppm) and W (120–11,660 ppm), and depleted in Nb (0.1–87 ppm) and Ta (0–7.1 ppm). The Zr/Hf ratios range from 23 to 52, with a mean value of approximately ~36, which is close to the chondritic values. These geochemical signatures, together with the occurrence of cassiterite intergrown with hydrothermal quartz and its replacement by later sulfides, support precipitation from a granite-related magmatic–hydrothermal system. Based on the findings and the literature, the Tieshilong deposit is therefore interpreted as a Pb–Zn-dominant expression of a Late Jurassic granite-related polymetallic system, in which deeper Sn ± W mineralization was overprinted by later Pb–Zn–Cu sulfide mineralization along fault-controlled fluid pathways. The recognition of cassiterite-bearing, medium- to high-temperature assemblages at depth suggests that down-dip extensions, fault intersections, and strike-inflection zones of the ore-controlling structures represent priority targets for future exploration.

The Dongliujia-Longkou gold deposit, situated on the northeastern margin of the Jiaolai Basin within the Jiaodong Peninsula, is a representative “Jiaodong-type” orogenic gold system. In the study area, the roles of deformation-induced microstructures in hosting invisible gold, controlling fluid pathways, and governing metasomatic enrichment have not been systematically investigated. To address this gap, we conducted an integrated study of pyrite hosted in leptynite and marble using Electron Backscatter Diffraction (EBSD) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) trace element analysis. EBSD results show that pyrite records a spectrum of deformation from dominant brittle fracturing with low intracrystalline strain to well-developed crystal-plastic microstructures. These deformation-induced microstructures generate high-density grain boundaries, dislocation-rich domains, and micro-fractures, which control gold enrichment through multiple mechanisms. The LA-ICP-MS trace-element signatures reveal that the study area is a meso- to epithermal system affected by successive pulses of magmatic-hydrothermal, metamorphic, and meteoric fluids. Au/As ratios, together with the scarcity of visible gold in many pyrite domains, indicate that a substantial proportion of gold occurs as invisible, lattice-bound gold within pyrite. Gold precipitation was primarily controlled by a combination of multiple processes, including water–rock interaction, fluid boiling, and meteoric water mixing. Overall, these results demonstrate that mineralization at the Dongliujia–Longkou mining district is a structurally controlled, multi-stage fluid–rock interaction system. The study proposes a macro- to micro-scale metallogenic model for the deposit and provides new constraints for deep and peripheral gold exploration in the Jiaodong Peninsula.