This study assesses the distribution and ecological risk of potentially toxic elements (PTEs: Cd, As, Pb, Cu, Ni, Cr, Zn, Ag) in ten surface marine sediments along the western Moroccan Mediterranean coast (Fnideq–Azla). The results demonstrate that PTE transport and accumulation are mainly driven by continental inputs, marine hydrodynamics, and coastal morphology. Oued Martil represents the main contamination source, pollutants are transported northwestward by longshore drift and subsequently trapped by the Cabo Negro and Ceuta headlands, creating distinct accumulation zones. While the geo-accumulation index (Igeo) shows varying enrichment levels, ranging from uncontaminated (Cr, Cu) to severe (Cd at Oued Martil), the Pollution load index (PLI: 1.19–2.70) indicates widespread anthropogenic impact across the region. Martil is the main pollution hotspot, followed by Fnideq, Cabo Negro, and Azla. The M'diq fishing harbor shows moderate impact, whereas the adjacent M'diq coastline and Restinga remain the least affected. Ecological risk assessment (PERI) highlights very high risk near Oued Martil and considerable risk in the northern sectors of coastal headlands. The total toxic unit (ΣTU) exceeded 3 at most sites, with Ni contributing the highest toxic load. The biological risk index (BRI: 0.17–0.42) reflects moderate risk corresponding to an 11–30 % probability of adverse effects occurring on benthic communities. Except at M'diq and Restinga, PTE levels exceeded the American National Oceanic and Atmospheric Administration (NOAA) safe thresholds. Our results surpass previous regional reports, marking this area as a critical hotspot with escalating contamination patterns.

The Miocene Asl Member in the North October Field, Gulf of Suez Rift, offers a well-exposed case study of syn-rift slope-apron sedimentation, where gravity-driven depositional processes, Syn-depositional faulting, and diagenetic evolution combine to create highly heterogeneous reservoirs. This integrated study synthesizes detailed core facies analysis, petrography analysis, structural interpretation, and dynamic production data to construct a predictive reservoir model linking facies architecture to reservoir performance. The methodology integrates 230 ft of conventional core description, thin- petrography, SEM imaging, porosity–permeability measurements, and historical production data from three wells (GS172-2, GS183-1, and OCT-J5) to ensure quantitative and reproducible interpretation. Three principal facies associations: Facies A: sand-prone gravity flows, Facies B: heterolithic debris flows and Facies C: carbonate-rich deposits establish a complex stratigraphic framework, vertically partitioned by diagenetic baffles and laterally segmented by active growth faulting. Diagenetic processes, particularly feldspar dissolution and pervasive carbonate cementation, amplify contrasts in reservoir quality, controlling porosity-permeability distributions across facies. Structural and stratigraphic compartmentalization govern distinct pressure regimes and flow unit behavior, reflected in differential production responses between fault blocks. High initial oil production is sustained from clean, sand-prone compartments, while water breakthrough and rapid decline are strongly influenced by intra-reservoir heterogeneity. The Asl Member case study enhances understanding of how sedimentary, diagenetic, and structural factors interact to shape reservoir performance in syn-rift settings, providing a methodological framework applicable to other tectonically active rifted margins. The multi-disciplinary approach presented here offers an effective predictive framework for exploration and development strategies in structurally complex clastic reservoirs worldwide.

The Kaiama gold deposit, located within the Proterozoic basement complex of northcentral Nigeria, is hosted predominantly in structurally controlled quartz-sulfide veins emplaced within mylonitized quartzite and talc schist units. The mineralization is spatially associated with NE–SW-trending ductile shear zones, interpreted as subsidiary structures of the regionally extensive Anka–Yauri fault system. While gold occurrences in Nigeria have been widely documented, the origin and evolution of the ore-forming fluids have continued to be a subject of debate. This study integrates fluid inclusion petrography, microthermometric analysis, and stable isotope (δ18O and δD) geochemistry to unravel the physicochemical conditions and fluid sources involved in the mineralization process. Detailed petrographic examination identifies a sulfide assemblage comprising pyrite, galena, chalcopyrite, chalcocite, and sphalerite, with quartz, sericite, and feldspar as the dominant gangue minerals. Fluid inclusion petrography revealed three distinct fluid types: Type I (carbonic aqueous three-phase fluids), Type II (vapour rich biphasic fluids), and Type III (liquid rich biphasic fluids), whose coexistence indicates fluid mixing as a key ore-forming mechanism. Microthermometric measurements yielded homogenization temperatures ranging from 169 °C to 339 °C and salinities between 0.4 and 15.3 wt% NaCl equivalent, consistent with low-to moderate-temperature, moderately saline hydrothermal fluids. Stable isotope compositions of fluid inclusions (δ18O_water = +1.57 ‰ to +7.07 ‰; δD_water = −114 ‰ to −33 ‰) point to a mixed fluid source, involving both metamorphic and meteoric components. Collectively, the results suggest that structurally focused fluid flow and mixing of contrasting fluid sources played a pivotal role in the precipitation of gold at Kaiama.

The Afyon Zone basement, regarded as part of the northern passive margin of Gondwana during the Late Paleozoic, comprises Paleozoic quartz-muscovite schists and phyllites intruded by Carboniferous metaplutonic bodies. The Triassic cover rocks consist of metadacite and ore-bearing metabasic. The plutonic assemblage in the area is represented by two principal intrusive phases: (i) metagranite porphyry and (ii) metagranite. Of these, age of the metagranite porphyry unit was determined to be 311.1 ± 5.0 Ma, and that of the metagranite to be 309.3 ± 1.9 Ma, using the U-Pb zircon SHRIMP method. Mineral chemistry analyses indicate that the temperature of the plagioclase in the metaplutonic and schist rocks is below 600 °C. The muscovite mineral in the schists is of the muscovite-ferromuscovite type and is crustal in origin. The metaplutonic suites correspond to S-type, peraluminous granitoids with high-K calc-alkaline affinities. Trace element distribution diagrams show enrichment in large ion radius lithophile elements (LILE; K, Rb, Th and U), while some high-field-strength elements (HFSE; Nb, Y and Sr) show depletion. The rare earth element distributions, are concave in shape (average LaN/LuN = 4–23) and exhibit a slight negative Eu anomaly (Eu/Eu∗ = 0.40–1.06). Both plutons are tectonically associated with a volcanic arc and formed within the continental crust. The primary magmas of the metaplutonic rocks formed through magmatic interaction with partially melted metapelitic rocks in the lithospheric mantle and the lower continental crust. Metamorphic basement rocks are high in potassium and exhibit a shoshonitic character. The average primary 87Sr/86Sr for metaplutonic rocks is around 0.720, while the 143Nd/144Nd values range from 0.512139 to 0.512257. These values suggest that the source area from which the plutons was originated from enriched-mantle. Accordingly, the Middle Carboniferous metagranitic magmatism in the Afyon Zone is interpreted to have developed within a continental volcanic arc setting associated with the southward subduction and progressive closure of the Paleotethys Ocean along the northern margin of Gondwana.

The heterogeneous nature of carbonate reservoirs necessitates an integrated evaluation of depositional, diagenetic, and mechanical attributes to predict their reservoir potential. The Sarvak Formation, a key Cretaceous carbonate reservoir in the Zagros Basin, hosts major hydrocarbon reserves in Middle East. This study combines petrographic observations, routine petrophysical measurements, and wireline logs to describe depositional microfacies, diagenetic features, geomechanical units (GMUs), and reservoir rock types. Six microfacies were identified, ranging from distal mid-ramp to lagoonal settings. Various diagenetic processes influence reservoir quality and connectivity of the pores. Four third-order sedimentary sequences were identified from the vertical stacking patterns of the microfacies. According to Lucia's classification, six reservoir rock types were defined, with reservoir quality increasing progressively from RT0 to RT5. Comprehensive geomechanical analyses, including unconfined compressive strength, Young's modulus, shear modulus, and Poisson's ratio, were conducted. The results show that these mechanical properties strongly control reservoir stiffness, ductility, and fracture susceptibility, and consequently influence fluid flow and storage capacity. Based on K-means clustering, four GMUs were identified, exhibiting a progressive increase in reservoir quality. GMU1 is predominantly associated with rock types 0 and 1, whereas GMU4 corresponds mainly to rock type 4, highlighting the systematic relationship between geomechanical behavior and reservoir rock quality. The integrated analysis of microfacies, diagenetic alterations, and geomechanical units demonstrates that reservoir quality improves from GMU1 to GMU4. Early transgressive systems tracts are mechanically stiff and contain limited porosity. In contrast, the overlying regressive systems tracts particularly in sequences 3 and 4, exhibit highly connected pore networks and superior fluid-storage capacity. These findings highlight the critical role of facies–diagenesis interactions in controlling both petrophysical and mechanical properties, providing a robust framework for reservoir characterization.