http://www.gsjournal.ir/ Scientific Quarterly Journal of Geosciences en daily 1 Mon, 22 Jun 2026 00:00:00 +0330 Mon, 22 Jun 2026 00:00:00 +0330 http://www.gsjournal.ir/article_242568.html This study aims to investigate the depositional environment of the Aghajari Formation (Upper Miocene-Pliocene) in the Hosseiniyeh area (Andimeshk). In this regard, three stratigraphic sections (Pa’alam, Khoshab, and Pirvali) were selected for study. The Aghajari Formation consists of sandstone, siltstone, mudstone, and shale, with a thickness exceeding 500 meters in the examined regions. Investigations in the field revealed 11 lithofacies, which include 6 sandstone facies (Sp/St/Sm/Sh/Sr/Sfl), 2 mudstone facies (Fm/Fl), 1 carbonate facies (bioclastic wackestone), 1 gray shale facies, and 1 skolithos ichnofacies. Evidence collected in the field suggests that the Pa’alam section exhibits characteristics of a deltaic environment, with delta-front facies containing sediments from the mouthbar, delta slope, and prodelta. In contrast, the deltatop facies includes deltaic channels and deltaic plains. This facies association constitutes the lower section of the Aghajari Formation. The upper part of the Aghajari Formation found in the Pa’alam section displays features typical of meandering rivers. The delta identified in the Pa’alam section is primarily river-influenced, with minimal tidal impact, where the maximum thickness of the tidal flat sediments reaches 2 meters. The two additional sections (Khoshab and Pirvali) were formed in a meandering river environment. http://www.gsjournal.ir/article_243333.html Heterogeneity in carbonate reservoirs is one of the key factors controlling reservoir quality and fluid flow. In this study, the heterogeneity of the Dariyan Formation in the Persian Gulf was evaluated using the Lorenz coefficient in combination with an integrated analysis of petrophysical and geological data. The study was conducted based on data from one well, incorporating quantitative interpretation of petrophysical logs, including gamma ray, bulk density, neutron porosity, sonic, and deep resistivity logs. In addition, 1093 thin sections from core samples were petrographically analyzed at the well scale to identify depositional facies, textures, microfacies characteristics, pore types, and dominant diagenetic processes. To quantitatively assess reservoir heterogeneity, the Lorenz coefficient was applied as a statistical index within depth intervals of 2 m. Lithological, textural, and facies-related heterogeneity in several intervals, shows a clear relationship with diagenetic trends. Increased heterogeneity is associated with reduction in average porosity and permeability, whereas diagenetic processes such as cementation and stylolitization locally reduce petrophysical heterogeneity. The findings provide a more detailed quantitative insight into intra-reservoir heterogeneity in the Dariyan Formation and highlight the applicability of the Lorenz coefficient for characterizing heterogeneity in carbonate reservoirs, with implications for improved reservoir modeling and production strategy optimization. http://www.gsjournal.ir/article_242427.html A detailed study aimed at investigating the abundance of Late Cretaceous ichnofaunal assemblages in the Jolfa area, East Azerbaijan Province, indicates that these assemblages are reliable tools for interpreting the depositional environment of submarine fans. The types of trace fossils and their stratigraphic arrangement are related to favorable biotic zones; therefore, they are employed to infer information concerning the differentiation of sub-environments within the turbidite fan system, sedimentation rate, and substrate consistency. The proximal and axial parts of the sandy system in the studied section contain assemblages characterized by low diversity and low bioturbation intensity, which are mostly dominated by post-depositional trace fossil suites. However, the distal parts show an increase in both diversity and bioturbation intensity, displaying pre-depositional trace fossil assemblages. The identified ichnofossil assemblages in the studied section correspond to the Nereites ichnofacies. Five sub-ichnofacies of the Nereites ichnofacies were recognized in the studied deposits, which may indicate a trend toward increasing water depth. These include: (1) Ophiomorpha rudis sub-ichnofacies, (2) mixed Ophiomorpha rudis–Paleodictyon sub-ichnofacies, (3) Paleodictyon sub-ichnofacies, (4) mixed Nereites–Paleodictyon sub-ichnofacies, and (5) Nereites sub-ichnofacies. http://www.gsjournal.ir/article_243726.html The Ghohroud granitoid complex, located southwest of Kashan in the central part of the Urumieh–Dokhtar Magmatic Arc (UDMA), mainly consists of granodiorite–tonalite rocks hosting mafic microgranular enclaves (MMEs) with compositions ranging from gabbrodiorite to tonalite. The main mineral assemblage includes amphibole, biotite, plagioclase, and alkali feldspar. Mineral chemistry indicates that plagioclase is andesine, amphiboles are Mg-rich hornblende, and biotites are also magnesium-rich. Amphiboles show relatively high Fe³⁺/(Fe³⁺ + Fe²⁺) ratios, while magmatic ones are characterized by low total Al and Fe/(Fe + Mg) ratios, suggesting crystallization under moderately oxidizing conditions. Oxygen fugacity (ƒO₂), calculated relative to the nickel–nickel oxide (NNO) buffer, ranges from 10⁻12 to 10⁻14 bar (ΔNNO +1.23) in tonalitic samples, and from 10⁻14 to 10⁻16 bar (ΔNNO +0.34) in granodioritic rocks and their associated enclaves. Thermobarometric calculations based on calcic amphiboles yield maximum pressures of about 4.39 kbar at 800 °C for tonalites, and around 3.89 kbar at 750 °C for granodiorites and their enclaves, corresponding to amphibole crystallization depths around ~12-16 km. Primary biotites in the Ghohroud granitoids crystallized slightly later, at 690–784 °C (average ~712 °C). http://www.gsjournal.ir/article_242745.html This study investigates the mineral chemistry, thermobarometric conditions, and petrogenetic evolution of Quaternary basaltic and olivine–basaltic lava flows exposed in the Negisan area, located in the southeastern segment of the Urumieh–Dokhtar Magmatic Arc (UDMA) and within the Dehaj–Sarduiyeh Magmatic Belt (DSMB). These volcanic units consist predominantly of porphyritic to glomeroporphyritic basalts characterized by phenocrysts of plagioclase (bytownite–labradorite), clinopyroxene (diopside–augite), and olivine (chrysolite), set within a microcrystalline to hyalomicrolitic groundmass. Comprehensive petrographic analysis reveals the pervasive presence of disequilibrium textures, including sieve-textured plagioclase and embayed olivine, indicative of dynamic open-system magmatic evolution. Quantitative major-element data obtained by electron probe microanalysis (EPMA) offer robust constraints on the physicochemical conditions of mineral crystallization. Clinopyroxene compositions correspond to an alkaline magma affinity and plot within the within-plate basalt tectonomagmatic field. Single-mineral thermobarometric calculations using clinopyroxene chemistry yield crystallization temperatures of 1160–1200 °C and pressures of 2–5 kbar, corresponding to mid- to upper-crustal magma storage depths (~7–18 km), under oxidizing and water-rich magmatic conditions. Systematic compositional contrasts between the olivine basalts (less evolved) and basalts (more evolved) demonstrate that fractional crystallization was the dominant differentiation mechanism. Nonetheless, petrographic evidence for magma mixing indicates that open-system recharge and interaction were also essential in magma evolution. These findings collectively support a model in which Negisan mafic volcanism represents late-stage, post-collisional magmatic activity associated with extensional tectonics following the final closure of the Neo-Tethys Ocean beneath the Central Iran microplate. The integration of petrography, mineral chemistry, and thermobarometry provides new insights into the magmatic plumbing system and geodynamic evolution of the southeastern UDMA. http://www.gsjournal.ir/article_245167.html Despite sharing several key features, the iron oxide–apatite deposits of the Bafq district, Central Iran, display variations in host rocks, wall rock alteration, and ore texture/mineralogy, and geochemical attributes, reflecting the complexity of the ore forming processes and the ore fluid sources. Here, oxygen and sulfur isotope composition of magnetite and pyrite, respectively, from various massive, vein-type, breccia, banded, and cumulate ores are used to investigate the source and evolution of the ore-forming fluids in the Bafq district iron deposits. The δ¹⁸O values of magnetite from Chadormalu, Gazestan, Mishdovan, Lak-e-Siah, and Se-Chahun deposits range from +0.7‰ to +8.2‰. Massive and vein-type magnetites exhibit lower δ¹⁸O values, between 0.7-4.4‰, consistent with crystallization from high-temperature magmatic fluids. The δ¹⁸O value of +3.9‰ for the banded ore at Mishdovan, interbedded with pyroclastic materials, indicates a significant contribution from high-temperature magmatic fluids. Magnetite from the cumulate ore in Chadormalu, yielded δ¹⁸O value at +2.5‰ implying formation under high-temperature magmatic conditions. In contrast, the higher δ¹⁸O values (up to +8‰) for magnetite from the Gazestan and Lak-e-Siah banded ore suggest deposition from non-magmatic fluids, compatible with a sedimentary–diagenetic origin or sub-seafloor replacement. The δ³⁴S values for pyrite from massive, brecciated, and vein-type ores range widely from +4‰ to +30‰, indicating the involvement of variable, dominantly nonmagmatic, sulfur sources. The broad ranges of oxygen and sulfur isotopic compositions suggest a multi-stage evolutionary model for mineralization, with contributions from both magmatic and non-magmatic fluid sources. This is supported by the fluid inclusion data, where wide ranges of fluid salinity and homogenization temperature are reported from various IOA deposits in the Bafq district, and even in individual deposits. http://www.gsjournal.ir/article_243525.html Pumped storage power plants play a crucial role in balancing electricity supply and demand during peak periods. Given the structural complexity of underground facilities and the potential risks of design oversights, this study evaluates the structural stability of the lower headrace tunnel bifurcation at the Rudbar Pumped Storage Power Plant in Lorestan, Iran. A multi-method approach was employed, integrating empirical classification systems (Q, RMR, RMi, GSI, and Protodiakonov coefficient) with 3D numerical modeling using FLAC3D software. Initial results indicated that the underground opening is marginally stable with a low factor of safety (FOS), necessitating the installation of a support system. Upon implementing the designed support system comprising 10 cm of reinforced shotcrete (steel grid) and 2 meter long fully grouted anchors in a 2×2 m pattern the internal forces were analyzed. The efficiency of the system was verified using capacity diagrams and Sakurai’s hazard level criteria, ensuring an FOS of over 1.5. Furthermore, the Ground Reaction Curve (GRC) and Longitudinal Deformation Profile (LDP) confirmed the elastoplastic behavior of the rock mass. Based on these analyses, an optimal excavation step of 2 meters (full-face) is recommended for ensuring the long-term stability of the tunnel bifurcation. http://www.gsjournal.ir/article_242428.html The interpolation of GPS velocity vectors into continuous fields represents a significant challenge in geodesy and geophysics. Conventional methods, such as the elastic Green's function proposed by Sandwell and Wessel (2016), face limitations in modeling complex phenomena and accounting for data uncertainties. This paper investigates the application of Physics-Informed Neural Networks as a powerful alternative to these classical methods. In this study, a PINN model was implemented that directly incorporates the governing equations of elasticity into the Neural Network's loss function. The model was trained on GPS data from 89 stations across the Alborz Tectonic Region in the oblique collision zone of the Arabia-Eurasia tectonic plates. Results demonstrate that the proposed model can successfully reconstruct the velocity field with acceptable accuracy, achieving RMSE values of approximately 0.68 mm/yr and 0.99 mm/yr for the east and north components, respectively. The method offers several advantages, including high flexibility in modeling complex physics, the capability to integrate diverse data types, and automatic consideration of observational uncertainties. Although the computational time of this approach is longer compared to classical methods, its inherent ability to overcome the limitations of traditional techniques makes it a promising candidate for the next generation of geodynamic data processing tools. http://www.gsjournal.ir/article_245045.html The Sadat iron deposit to the west of the Siriz in the southern section of the Kashmar-Kerman block (KKB), Central Iran structural zone, is closely associated with a syenitic-monzonitic pluton, here referred to as Siriz intrusive body, intruded into the Cambrian sedimentary rocks. Calc-silicate minerals typical of skarns including anhydrous garnet-pyroxene- wollastonite, and hydrous phlogopite-epidote-tremolite-actinolite are developed in Sadat, the former minerals being of limited extent. The intrusive body is variably albitized to a distance from the ore deposit. Ore formation occurred with the retrograde skarn. Magnetite is the main ore mineral, commonly containing minor late pyrite and locally chalcopyrite. The iron ore occurs in massive, banded, and locally breccia textures, and distinguished by relatively low contents of the magnetite-compatible metals, Ni-Cr-V-Ti-Co. The spatial relations between the intrusive body and surrounding rocks suggest a post-Cambrian−pre-Triassic timing for emplacement of the intrusion and ore formation. The Sadat deposit is comparable in some respects, including albitic alteration, late pyrite, and low Ti contents, to iron oxide-apatite deposits of the Bafq-Saghand district in the central KKB. Significant differences, however, exist in host rocks (Middle-Upper Cambrian sediments and post-Cambrian intrusive body in Siriz; Early Cambrian, dominantly volcanic-subvolcanic rocks in Bafq-Saghand), and scarcity of apatite. http://www.gsjournal.ir/article_246051.html Mohammadabad titanium paleoplacer deposit is located in the Sabzevar subzone, NE Iran. This deposit occurs as a stratiform within the ore-bearing sandstone horizon of Middle-Late Eocene marly- conglomerate- limestone- sandstone sequences. Oxide minerals observed as stratiform, lenses, and disseminated forms. Oxide mineral assemblages comprise titanomagnetite, ilmenite, and magnetite. Mineral chemistry of the oxide minerals yields TiO2 in the range of 12.87–20.75 wt.% and Fe2O3 from 39.99–64.68 wt.%, values. Comparison of geochemical patterns of elements in sandstones with same patterns in Late Cretaceous mafic-intermediate intrusions of the region, along with the presence of significant amounts of titanomagnetite and magnetite in the mineral composition of these igneous rocks, indicates that the Late Cretaceous monzogabbro, diorite, and monzodiorite intrusions, aged 100 to 75 million years ago, are the probable source rocks of the oxide minerals in the sandstones of southern Sabzevar. These intrusive rocks are outcropped in the form of sill within the Late Cretaceous volcanic-sedimentary sequences in the southern Sabzevar region. The Mohammadabad titanium deposit is a paleoplacer that originated from the weathering and erosion of Late Cretaceous outcropped rocks, and was deposited in the shallow fluvial and coastal environments of the foreland of the Sabzevar ocean basin during Eocene http://www.gsjournal.ir/article_246354.html The Alvand and Boroujerd intrusive bodies are among the largest coeval plutons in the northwestern part of the Sanandaj–Sirjan Zone. Both bodies preserve magmatic, transitional, and solid-state fabrics, though with notable differences. In the Alvand granite, magmatic fabrics are generally well preserved across most parts, whereas in the Boroujerd granite, they are largely obliterated by overprinting solid-state fabrics. Moreover, mylonitization is much more pronounced in the Boroujerd granite than in the Alvand granite, indicating stronger overprinting by subsequent deformation. Transitional fabrics in both bodies are expressed by the occurrence of late-stage minerals within fractured domains. In the Alvand granite, although both magmatic and transitional fabrics are well preserved, mylonitization is not pervasive throughout the entire pluton, suggesting that this pluton was not uniformly affected by later deformation. Field and microstructural evidence further indicate that the Alvand pluton formed within an open, dynamic, and multiphase magmatic system. In contrast, the Boroujerd pluton exhibits features of a relatively closed system, where crystallization occurred under comparatively calm conditions without significant magma flow perturbations, and deformation was mostly restricted to the solid state after complete cooling. http://www.gsjournal.ir/article_246443.html This study investigates the impact of the Guriyeh earthquake swarm, which occurred between November 2017 and July 2018 in the Shushtar and Mianab aquifer systems, on groundwater levels and hydrochemistry. Groundwater data from production wells , geological maps, and earthquake bulletins were integrated to evaluate groundwater table fluctuations and variations in EC, TDS, pH, and major ions (Na⁺, K⁺, Ca²⁺, Mg²⁺, HCO₃⁻, Cl⁻, and SO₄²⁻) before and after the seismic swarm. Spatial interpolation using the Kriging method in GIS revealed that seismic activity altered groundwater flow paths through fracture opening and enhanced fault permeability, resulting in significant hydrochemical changes. Following the earthquake swarm, EC and TDS increased markedly along active faults and in areas with the highest seismic density, indicating the upward migration of deeper saline fluids. Spatial distributions of Na⁺, Ca²⁺, Mg²⁺, SO₄²⁻, and Cl⁻ shifted from widespread patterns to localized clusters, suggesting reactivation of fault-controlled hydrogeological pathways. Concurrent decreases in SO₄²⁻ and increases in pH likely reflect pore-pressure changes, intensified water-rock interaction, and mixing of shallow and deep groundwater. These findings demonstrate that the Gurieh earthquake swarm exerted a measurable influence on aquifer hydrochemistry and may serve as an indicator of concealed faults and preferential subsurface flow pathways. http://www.gsjournal.ir/article_248366.html Sistan and Baluchestan Province is located in southeastern Iran. Its geology, magmatism, and metallogeny have been largely controlled by tectonic events related to the opening and closure of the Neotethys. Several magmatic episodes have occurred in the province, some of which are particularly significant for mineralization and metallogeny. Remnants of the Neotethys oceanic crust, preserved as Cretaceous ophiolitic sequences, host mineralizations of chromium, copper, manganese, iron, titanium, and magnesium. The Cretaceous Bazman granitoids are likely associated with iron, copper, zinc, tungsten, and tin mineralization and were generated from magmas related to the subduction. Upper Eocene–Lower Oligocene subduction and collisional magmatism led to the formation of the Zahedan granitoids, and the associated hydrothermal fluids produced gold, antimony, and copper mineralization. Olig-Miocene post-collisional magmatism in the northern parts of the province resulted in the development of porphyry, epithermal, and skarn mineralization systems at Lar, Janja, Seyasteragi, Kaftarkuh, Kalegar, and Asagi. Olig-Miocene magmatism related to subduction also generated skarn iron, porphyry copper–gold, and epithermal gold mineralization in the Samsur, Mirabad, Qalehsouli, Bidster, Kuh-e Madofti, Kharestan, and Sarkahnu areas. The Plio-Quatrnary subduction-related magmatism at Bazman and Taftan is particularly important for gold mineralization and geothermal energy potential. http://www.gsjournal.ir/article_248367.html The Dahane-ye Gomrokan copper deposit, located in the southern part of the Kerman porphyry belt within the Urumieh-Dokhtar magmatic arc, is one of the few systems that exhibits evidence of formation in a magmatic-hydrothermal environment with a reducing nature. Three stages of post-Eocene intrusive bodies have been identified in this deposit. The quartz-monzonite to quartz-monzodiorite body is the primary host for copper mineralization. Alteration zones include silicification, potassic, phyllic, argillic, propylitic, and carbonatization. The widespread occurrence of potassic alteration, along with the presence of hypogene sulfide minerals, the absence of magnetite, primary hematite, and anhydrite, and the occurrence of reducing minerals such as pyrite, ilmenite, and arsenopyrite, all indicate a reducing system. Alteration patterns, mineralization features, and their relationship with the intrusive bodies provide valuable evidence for the formation of this deposit in a reducing environment. This contrasts with classical oxidized porphyry models in Iran, which exhibit distinct mineralogical and metallogenic characteristics. These results not only present a new model for interpreting alteration and mineralization processes in the southern Kerman porphyry belt but also have the potential to play a key role in revising exploration models and identifying other reducing porphyry systems within the Urumieh-Dokhtar magmatic arc. http://www.gsjournal.ir/article_248581.html In this study, the alluvial terraces of southern Lorestan (Mamulan–Poldokhtar region) were investigated using petrographic and geochemical approaches to determine their provenance. Four alluvial terrace outcrops along the Mamulan–Poldokhtar road were selected for sampling. Fifteen gravel-sized clast samples were collected for petrographic investigation, 20 sandstone samples were selected for modal analysis, and 12 mudrock samples were analyzed geochemically using XRF and ICP–MS. Modal analysis of the sandstone samples plotted on the QmFLt diagram indicates a recycled orogen provenance. The petrofacies of the studied deposits, based on the QFL diagram, are dominated by chert arenite and calclithite arenite. The abundance of sedimentary lithic fragments, particularly chert and carbonate clasts, indicates extensive recycling of older sedimentary successions and demonstrates that sedimentary recycling was the dominant process controlling the provenance of the detrital material. Geochemical results indicate that the source rocks experienced moderate chemical weathering under arid climatic conditions. http://www.gsjournal.ir/article_250393.html The Neogene perlitic rocks of the Galumak area, located northeast of Bardsir and within the Urumieh-Dokhtar magmatic assemblage, are associated with limited extent rhyolitic lava flows. These perlites appear to have formed through hydration of rhyolites, progressively devitrifying into spherulites. Geochemical data reveal a rhyolitic composition, high-K calc-alkaline affinity, and meta- to peraluminous character. Spider diagrams and rare earth element (REE) patterns exhibit LREE enrichment relative to HREE, with negative Nb-Ti and Eu anomalies, indicative of an arc-related source, involvement of continental crust, and the role of fractional crystallization (particularly plagioclase and zircon) in magma evolution. Tectonomagmatic discrimination diagrams place the samples in a syn- to post-collisional setting. Geochemical evidence, including incompatible element ratios, suggests that the magma originated from partial melting of meta-greywacke in the middle to upper continental crust. Considering the tectonic setting and Miocene age, the formation of these acidic rocks is attributed to melting of thickened continental crust in a syn- to post-collisional environment, likely triggered by processes such as slab breakoff or lithospheric delamination. These findings provide significant insights into the closure of the Neotethys Ocean and the crustal evolution of Iran during the Miocene.