Journal of Himalayan Earth Sciences

Mineralogical, and Geochemical Investigation of Sulfide Mineralization in Ushiri Valley, Western Kohistan Island Arc, Pakistan: Implications for Genesis

Israr Ud Din — 2026-04-01

The Ushiri Valley sulfide mineralization, a newly identified deposit in the Upper Dir region, is located in the western part of the Kohistan Island Arc, northern Pakistan. The mineralization occurs within massive amphibolites of the Kamila Amphibolites and the granodiorite and granite of the Kohistan Batholith. Three types of mineralization have been identified: 1) sulfide mineralization along quartz veins, 2) disseminated sulfide mineralization in the host rocks, and 3) supergene enrichment along localized shear zones. The amphibolites, granodiorite, and granite of the study area are extensively intruded by quartz veins, which generally host sulfide mineralization mainly in the form of chalcopyrite and pyrite, with a lesser amounts of bornite, galena, and sphalerite. Secondary minerals such as malachite, azurite, and limonite/hematite occur as products of supergene enrichment. The host rocks adjacent to the mineralized quartz veins contain the same sulfide mineral assemblage in disseminated form. Hydrothermal alteration, including saussuritization, sericitization, kaolinization, propylitization, and silicification is commonly observed in the mineralized host rocks within shear zones and at the contact between mineralized quartz veins and the host rocks. Geochemical data from hydrothermally altered host rocks indicate that the mineralizing hydrothermal fluids were significantly enriched in FeO, K₂O, and Cu, while the Pb, Zn, W, Cr, Ni, and Co show slight enrichment. Sulfur (δ³⁴S) and oxygen (δ¹⁸O) isotopic data suggest the involvement of heavy magmatic fluids related to deep-seated intrusions. These fluids likey formed metal complexes and acted as high-temperature metalliferous fluids responsible for the precipitation of base metals sulfides within quartz veins and the associated host rocks, which can be correlated with a porphyry-type mineralizaton system.

Micropaleontological Approaches to South Caspian Oil and Gas Development

Arzu Javadova — 2026-04-01

The South Caspian Basin is among the most structurally complex and geodynamically active regions globally, characterized by rapid sedimentation, high subsidence rates, extensive overpressure zones, and frequent mud volcanism. Together with strong seismicity, these factors pose substantial engineering challenges for offshore oil and gas development. Quaternary deposits, which underpin most offshore facilities, are critical to the safe and economical design of platforms, drilling rigs, and subsea infrastructure. Yet despite extensive studies of Caspian Sea sediments, engineering–geological data on the physical and mechanical properties of Quaternary deposits in hydrocarbon-bearing areas remain insufficient.

This study integrates micropaleontological, lithological, and stratigraphic analyses of 300 core samples from 70 boreholes across 45 offshore structures to characterize the composition, distribution, and engineering relevance of Quaternary deposits. For the first time, a detailed stratigraphic subdivision based on ostracod fauna is presented, comprising five supra-horizons, ten horizons, and seven biozones defined by index species. Eleven characteristic ostracod assemblages were identified, enabling correlation of deposits across the Apsheron and Baku archipelagos and the Turkmenian sector.

Results show pronounced lateral and vertical lithologic variability, strongly controlled by depositional environment, structural setting, and post-depositional processes. Quaternary sequences include Bakuvian, Khazarian, Khvalynian, Novo Caspian, and modern sediments, with facies ranging from fine-grained clays in deep-water settings to loams and sands in nearshore and eastern shelf areas. Integrating micropaleontological data with lithostratigraphy improves geotechnical mapping and zonation, supports the prediction of overpressure zones, and reduces development risk.

These findings establish a new stratigraphic framework for the Quaternary in the South Caspian Basin and provide essential baseline data for offshore engineering, supporting safer infrastructure design, optimized field development, and risk mitigation in one of the world’s most challenging petroleum provinces.

Modulation of Australian Summer Surface Heat Fluxes by Coupled Indian and South Pacific Highs

Nasir Ilyas — 2026-04-01

This study investigates the combined influence of the Indian Ocean High Pressure (IOHP) and South Pacific High Pressure (SPH) systems on summer (DJF) surface heat fluxes and regional thermal conditions over the southeastern Indian Ocean and eastern Australia during 1988–2017. Using the Center of Action (COA) framework, years were classified into combined phases, identifying six HH (high IOHP–high SPH) and six LL (low IOHP–low SPH) years. Composite analyses reveal that HH years exhibit drier air, suppressed evaporation, and reduced latent heat flux (LHF), alongside moderate increases in sensible heat flux (SHF), enhancing near-surface warming. Thermodynamic anomalies (Qa, Qs, Ta, Ts) overlaid with wind vectors indicate enhanced boundary-layer stability and strengthened easterly to southeasterly flow, limiting onshore moisture transport and confirming weaker air–sea interaction during HH phases. Correlation analyses show a significant negative association between IOHP and LHF (r = –0.38, p < 0.05) and positive spatial coupling between IOHP longitude and SPH pressure (r = 0.40, p < 0.05), highlighting the role of subtropical highs in modulating surface fluxes. Detrended spatial correlations further indicate IOHP–SPH as primary drivers of LHF and SHF variability, while broader climate modes—SAM, IOD, and ENSO (Niño 3.4, Niño 4)—exert secondary, regionally modulated influences on surface fluxes and seasonal skin temperature. Spatial trend analyses reveal declining LHF across the subtropical southeast Indian Ocean, heterogeneous SHF patterns, and subtle sea level pressure increases, suggesting potential IOHP intensification. Monte Carlo and bootstrapped tests confirm the robustness of these results. Overall, coupled subtropical highs dominate regional ocean–atmosphere energy exchange and surface heating patterns, providing a process-level understanding of how circulation anomalies amplify summer climate extremes in a warming climate.

Preliminary paleomagnetic constraints on vertical-axis rotations and tectonics of the Makran–Khojak Flysch Basin, Pakistan

Waseem Khan — 2026-04-01

The Makran-Khojak Flysch Basin (MKFB), situated in the northwest of the Indian Plate in Pakistan, exhibits a comprehensive sandstone sequence. This sequence has experienced significant tectonic bending and rotation due to orogeny during plate convergence. The MKFB is a compelling case study for examining the geological characteristics of an active convergent plate boundary marked by the oceanic lithosphere subduction. This is a preliminary investigation with specimen limitations, and the vertical axis rotations (VARs) obtained from preliminary paleomagnetic (PMag) data and geodynamic investigations offer a first-order constraint on the tectonic deformation within the MKFB. The findings show that the east-west trend rotated clockwise (CW) due to the subducting Arabian Plate underneath the Makran. The north-south trend rotated counter-clockwise (CCW) due to the main stress-strain driven by the Chaman fault in association with the northwest advance of the Indian Plate. The exception of CCW rotation of the GA section with < 1° acts as a transition zone, which has been influenced by the interactions between the CRA, Afghan Block, Arabian Plate, Indian Plate, and the Chaman Faults’s strike-slip movement. Additionally, pre-depositional tectonic deformations occurred between the Arabian and Indian plates, with tranpressional interactions bringing up an NNE-SSW convergence zone without any tectonic deformation in the Makran arc-trench gap until the late Eocene. While the post-depositional tectonic deformations of the MKFB occurred since the late Eocene, presenting the tectonic interactions between Indian and Eurasian plates. Whereas the interactions between the Eurasian, Arabian, and Indian plates occurred throughout the Oligocene to late Miocene, which originated the Chaman Transform Fault. Moreover, the geodynamic results show that the MKFB formed as a minor symmetry typical of a Y-shaped junction similar to that of a horsetail structure during Oligocene to Miocene.

Toxicity Potential of Lead in Nile Tilapia (Oreochromis niloticus) Using Bioaccumulation and Oxidative Stress Indicators

Arooj Atiq — 2026-04-01

This contemporary study was carried out to determine the toxicity potential of lead (Pb) using the fish Oreochromis niloticus as a bioindicator. Further, the study was also undertaken to determine the oxidative stress, bioaccumulation factor, metal pollution index, and antioxidant enzymatic and non-enzymatic activities of CAT, GST, and GSH in different fish organs due to absorption of Pb. A total of 50 fish were exposed for 30 days to graded Pb concentrations (0.08, 0.016, 0.0016, and 0.000016 mg/L) under controlled laboratory conditions. Pb accumulation was organ-specific, with the highest concentrations in muscles (0.409 mg/kg) and gills (0.247 mg/kg), both exceeding the WHO permissible limits for fish tissues. The bioaccumulation factor (BAF) followed the order muscle > brain > heart > liver > gills, indicating preferential storage in metabolically active tissues, while the metal pollution index (MPI) reflected an overall low contamination degree. Oxidative stress biomarkers revealed marked alterations in enzymatic activities: catalase (CAT) activity decreased by 41.3 % in liver and 2.0 % in gills, glutathione S-transferase (GST) by 13 % in liver and 27.7 % in gills, and reduced glutathione (GSH) by 12.7 % in liver and 14.7 % in gills, demonstrating a clear Pb-induced oxidative imbalance. The enzyme suppression corresponded with elevated Pb residues in tissues, reflecting compromised antioxidant defense mechanisms. These findings confirm that even low Pb exposure disrupts biochemical homeostasis and promotes oxidative stress in O. niloticus. The results emphasize the utility of oxidative biomarkers as sensitive indicators of heavy-metal pollution and highlight the urgent need for stricter monitoring of aquaculture and freshwater systems to mitigate potential ecological and public-health risks.

Innovative Trend Analysis of Hydrometeorological Parameters in the Upper Indus Basin, Pakistan

Farjad Aziz — 2026-04-01

This study aims to identify climatic shifts and their implications for water resource management, particularly with the Tarbela Dam. The innovative Trend Analysis (ITA) method was used to determine key hydrometeorological parameters' monthly and seasonal trends, including precipitation, relative humidity, solar radiation, maximum and minimum temperatures, and inflows, in the Upper Indus Basin, Pakistan. Historical time series data spanning 1981 to 2024 evaluated past trends while future climate projections spanning 2025 to 2100 were obtained from the CMIP6 model using two scenarios, SSP2-4.5 and SSP5-8.5. Historical data reveals a decreasing precipitation trend in spring by -0.007mm/year. Future projections under SSP2-4.5 and SSP5-8.5 also suggest a decreasing trend of precipitation. Tmax increased by 0.118°C/year in Spring historically, while under SSP2-4.5 a strong increase of 0.155°C/year is observed in spring, and under SSP5-8.5 about 0.2°C/year. Tmin showed a positive trend of 0.095°C/year in spring, while for SSP2-4.5 dominant increase occurred in spring by 0.137°C/year, and for SSP5-85 increased about 0.155°C/year. Relative humidity slightly increased by 0.046 %/year in the monsoon period and for SSP2-4.5 and SSP5-8.5 it shows a slight increase whereas in solar radiation, historical trends increased by 6.563 W/m²/year for spring and SSP2-4.5 about 7.745 W/m²/year and for SSP5-85 increased about 9.028 W/m²/year during spring. Historical inflows increased during summer by 0.589 m³/s/month and for SSP2-4.5 increased by about 1.017 m³/s/month and for SSP5-85 about 1.3 m³/s/month during summer. This study demonstrates ITA's effectiveness and supports sustainable water management in the Upper Indus Basin underscores the urgent importance for water resource managers to adopt adaptive reservoir management and policy adjustments at Tarbela Dam to ensure long-term water security.

Hydrological Response and Flood Potential Assessment of a Tropical Small Island: Integration of Geomorphometric Indices and Water Balance in Wai Ruhu Watershed, Ambon, Maluku, East Indonesia

Nabila Kalsum Tuanany — 2026-04-01

High annual rainfall on Ambon Island significantly increases its vulnerability to hydrological disasters, particularly flooding. This study evaluates flood potential in the Wai Ruhu Watershed by integrating geomorphometric indices with water balance analysis. Geomorphological characteristics, including stream order, bifurcation ratio (Rb), drainage density (Dd), form factor (Rf), circularity ratio (Rc), and elongation ratio (Re), were analyzed using ArcGIS 10.8. The water balance was determined using 11 years of precipitation and evapotranspiration data (2014–2024), while surface runoff and infiltration were estimated based on land cover and slope gradients. The results indicate that the watershed’s low bifurcation ratio and moderate-high drainage density reflect a rapid hydrological response and strong structural control on flow. Furthermore, steep topography and land cover changes significantly increase the runoff coefficient, leading to high surface discharge and limited infiltration. The integration of these parameters confirms a high flood risk, particularly in densely populated downstream areas. These findings provide a critical framework for watershed management and land-use planning to mitigate hydrological hazards in small tropical island environments such as Ambon City.

Climate Change Influence on Streamflow Projections Across the Chenab River Basin in Pakistan Under CMIP6 Scenarios

Tabinda Masud — 2026-04-01

This study investigated the historical and projected climatic and hydrological patterns in the high-altitude Chenab River Basin for the 21^st century. It has been observed that the average temperature (30.61 ^°C) for the 1981-2010 baseline period is expected to increase by 2.00 ^°C (2.65 ^°C) in the mid-century (2041-2070) and 2.82 ^°C (5.05 ^°C) in the late-century (2071-2100) under SSP 2-4.5 (SSP 5-8.5). Similarly, a 3.74% and 4.71% increase in precipitation is concluded for the mid and late centuries under SSP 2-4.5, while a 7.09% and 13.03% increase is recorded under SSP 5-8.5. Although average annual flows are projected to increase by 9.52–20.82% relative to the base period by 2100, a decline is expected in the late century compared to mid-century. This analysis reveals a significant rise in the peak flow's amplitude and an earlier accomplishment. As a result, hydrological extremes are likely to intensify. The optimal management of hydrological resources in the basin will require substantial modifications to the construction and maintenance of storage reservoirs, irrigation withdrawals, flood alleviation, drought control measures, and action plans.

The geophysical approach to interpret reservoir characterization of the Middle Jurassic Shinawari Formation, Upper Indus Basin, Pakistan

Muhammad Salman — 2026-04-01

The Shinawari Formation of Middle Jurassic age is represented by the stratigraphy of mixed carbonate and clastic rocks. The present study attempts to incorporate data from subsurface wells CDW 01 and MW 01 and seismic lines, covering the area of the Upper Indus Basin, Pakistan. In the CDW 01 well, the Shinawari Formation reaches a total thickness of about 71 m, between 4579 and 4650 m. Zone 1, the principal zone of interest, is developed between 4580 and 4635 m, having 39% Ω·m water resistivity (Rw), 4.2% average porosity (PHIE), 58 μs/ft Delta-T (DT) value, and 8% effective porosity. At the CDW 01 well, the reservoir shows approximately 68% water saturation (SWA) and 32% hydrocarbon saturation. While the MW 01 well is characterized by 116 meters of thickness, having a zone of interest designated as zone 1 with 32% average shale value, 49 % Ω·m water resistivity (Rw), 64% average porosity (PHIE), 50.64 μs/ft Delta-T (DT) value, and 20.0 % effective porosity. At the MW 01 well, the reservoir shows approximately 42% water saturation (SWA) and 58% hydrocarbon saturation. Furthermore, depth contour and two-way time (TWT) maps are generated and interpreted from the seismic data. Furthermore, an integrated approach from seismic and well logs (Bulk density vs Neutron porosity cross plot) data portrays that the Middle Jurassic, Shinawari Formation has good potential for the indigenous hydrocarbons and heavy minerals.

Evaluating Fold-Thrust Structures and Hydrocarbon Potential in the Western Marwat-Khisor Ranges and Sheikh Budin Hills, North Pakistan

Iftikhar Alam — 2026-04-01

The Marwat-Khisor Range, part of Pakistan’s Himalayan frontal fold-thrust belt, showcases thin-skinned tectonics driven by north-south crustal shortening from the Indo-Asian collision. This work presents the structural style, geometries, and potential of the hydrocarbon in the western part of the Marwat Khisor and Sheikh Budin hills. The key structures include the south-divergent thrust sheets, asymmetric folds, and active faults (e.g., Khisor Frontal Thrust) juxtaposing Cambrian strata against younger sediments. Recent deformation near Dhupsari shapes the Punjab foredeep basin, accumulating synorogenic deposits having Permian-Triassic marine sequences that correlate with adjacent ranges. The notable units have shale with high organic content that is rich in carbon, as seen in the outcrop. These units are the Amb Formation and the Sardhai Formation of Permian Age. Based on outcrop observations, these units can act as source rock in the area. The Reservoir potential exists in porous Permian sandstones (e.g., Warchha Sandstone), sealed by Triassic evaporites. The Structural traps (anticlines, fault compartments) and thick carbonate overburden enhance hydrocarbon retention. This system mirrors productive analogs in the Potwar Basin, suggesting significant untapped potential. Recommended exploration includes 3D seismic surveys and geochemical analysis to target areas where mature source rocks align with structural complexity. The region is positioned as a promising frontier for hydrocarbon development, having source, reservoir, and cap rocks within Pakistan’s fold-thrust belt.