Igneous intrusives in northern Pakistan can provide valuable insights into pre-Himalayan metaluminous to peraluminous magmatism along the northern boundary of the supercontinent Gondwana and its potential tectonic significance. This study generates new geochronologic, petrographic and geochemical data for intermediate (monzonite, syenite, and foid syenite) and felsic (granite and quartz monzonite) rocks within the NW Himalayan region of Pakistan. Both the intermediate and felsic rocks have values of A/NK > 1.1, implying a metaluminous to peraluminous composition, and are distinguished by high FeOT/(MgO + FeOT) (0.81-1.0), high 10,000 x Ga/Al ratio (2.1-5.1), elevated Nb + Zr + Y + Ce contents (122-1,204 ppm), and negative anomalies of P and Ti, consistent with aluminous A-type magmatic affinity. These rocks are classified as A(1)-type, which is linked to anorogenic intraplate extensional setting. Both rock groups yield high calculated average whole-rock Zr saturation temperatures (i.e., T-Zr; 790-823 degrees C), which suggests formation from high-temperature magmas. Whole-rock geochemistry, including variable (Sr-87/Sr-86)(i) values (0.7034-0.7086), positive epsilon Nd(t) (+0.1 to +3.9), high Pb isotopic values (that is, (Pb-206/Pb-204)(i) = 18.68 to 19.31, (Pb-207/Pb-204)(i) = 15.64 to 15.74, and (Pb-208/Pb-204)(i) = 38.93 to 39.78), and variation in zircon epsilon Hf(t) values (+0.8 to +7.0), indicates diverse magma sources for the intermediate-felsic rocks and provide evidence of partial melting of metasomatized lithospheric mantle, producing a primary magma of foid to quartz syenitic composition. Subsequently, this magma was responsible for the partial melting of the overlying juvenile crust, producing granitic, quartz monzonitic and monzonitic magmas. During the magma evolution process of these rocks, this process was primarily determined by partial melting that followed fractionation of K-feldspar, ilmenite and apatite. T-DM2 ages indicate that the parent materials of intermediate-felsic rocks were generated during the Mesoproterozoic-Neoproterozoic. LA-ICP-MS U-Pb dating of magmatic zircons documents their formation in the Late Paleozoic at similar to 278-268 Ma. The intermediate-felsic rocks are correlatable with alkaline igneous rocks of the Peshawar Plain, which record the breakup of the supercontinent Gondwana and the subsequent opening of Neo-Tethys during a Late Paleozoic rifting event. The nepheline syenite records a younger episode during the Cenozoic (37 Ma), corresponding to the collision of the Indian-Eurasian tectonic plates.

The Koga Carbonatite-Alkaline Complex (KCAC) in northwestern Pakistan is emplaced within the Early Paleozoic Greater Himalayan Sequence of the region, marking a significant magmatic event. The complex primarily comprises quartz syenite, nepheline syenite, and carbonatite lithologies. Apatite grains extracted from these lithologies were systematically analyzed using cathode-luminescence (CL) imaging, trace elements and Sr-Nd isotopic compositions, and LA-ICP-MS U-Pb geochronology. The homogeneous cathode luminescence of apatite grains from quartz syenite (Q-Ap1), nepheline syenite (N-Ap1) and carbonatite (C-Ap1) and their high concentrations of REE (2400 ppm - 22,130 ppm; 3832 ppm - 14,532 ppm; and 2494-9050, respectively), particularly light REE (with LaN/YbN = 12 to 78; 22 to 113; and 30-166; respectively), indicate their magmatic origin. Texturally and chemically zoned apatite from nepheline syenite (N-Ap2) and carbonatite (C-Ap2) are also enriched in light REE (LaN/YbN = 38 to 97 and 24 to 108; respectively) relative to heavy REE, which is consistent with a magmatic origin. The Q-Ap1 apatite are showing distinct negative Eu anomalies (0.18-0.75) indicative of crystallization from an evolved melt that experienced significant plagioclase fractionation. The N-Ap2 apatite exhibit a rim-ward increase in REE + Y contents, which can be attributed to fractional crystallization of pyroxene, alkali feldspar and biotite. While in C-Ap2 the rim-ward increase in REE + Y is coupled with increasing Na and decreasing Mn, suggesting early crystallization of calcite. Moreover, patchy texture and depleted REE + Y contents of N-Ap3 apatite from coarse-grained nepheline syenite compared to N-Ap1, reflect their metasomatic nature by interacting with fluids. However, N-Ap3 show similar initial Sr and Nd composition with magmatic apatite from nepheline syenite (i.e., N-Ap1) suggesting that the fluids involved in metasomatic alteration were likely originated from the cooling host magma. The LA-ICP-MS U-Pb apatite geochronology data from KCAC align closely with previously published zircon U-Pb ages, indicating rapid cooling following the emplacement of the complex. The U-Pb dating of apatite yields an emplacement age of 287 +/- 16 Ma, 279 +/- 9 Ma and 274 +/- 9 Ma for the quartz syenite, nepheline syenite and carbonatite, respectively; implying their emplacement during the Permian rifting and breakup of the northern margin of Gondwana. The Sr and Nd isotopic compositions of apatite from the KCAC imply a sub-lithospheric mantle source, with minimal crustal contamination or interaction with metasomatized sub-continental lithospheric mantle. The study demonstrates that apatite textural features combined with in-situ trace elements and Sr-Nd isotopic compositions can be an effective tool to unravel complex magmatic and hydrothermal processes and nature of the magma source of carbonatite- alkaline complexes.

The Kohistan-Ladakh Arc records terrane accretion and continental growth history from the opening to the closure of the Neo-Tethys. However, its role in the Neo-Tethys evolution and implication for continental crustal growth remain debated. This study present the first comprehensive dataset on the newly identified Katisho ultramafic-mafic-intermediate rocks within the Ladakh Batholith, including field and petrographic features, in- situ zircon U-Pb ages and Lu-Hf analysis, mineral chemistry, bulk-rock elemental and isotopic (Sr-Nd) compositions, aiming to have a better understanding the building up of the Kohistan-Ladakh arc and its role in the Neo-Tethys evolution. The Katisho gabbros and granodiorites, located on the northwestern side of the Ladakh Batholith, contain irregular ultramafic enclaves. Zircon U-Pb dating reveals that the gabbro and granodiorite were emplaced coevally at ca. 66.6 Ma. Geochemical signatures, such as enriched LILE, depleted HFSE, and consistent LREE-enriched REE patterns, show typical features of the arc-related calc-alkaline magmatisim. Their depleted whole-rock Sr ([87Sr/86Sr]i = 0.7041 to 0.7045), Nd [8Nd(t) = +2.4 to +3.2], and zircon Hf [8Hf(t) = +4.1 to +11.1] isotopic compositions, along with their elemental features (enriched LILE, low FC3MS values [0.4--0.6], and Cpx: Grt ratio = 6:1) collectively demonstrate a common origin from a depleted lithospheric mantle source, predominantly spinel-bearing peridotite metasomatized by slab-derived fluids. The diverse type of the intrusions can be attributed to the fractional crystallization of a common primary mafic magma. This study, combined with previous research, concludes that the Paleocene Katisho intrusions were genetically related to the rollback of the Neo-Tethyan Oceanic slab beneath the Asian margin. This magmatic phase marks the transition of the Kohistan-Ladakh arc from an intra-oceanic arc to an Andean-type continental margin, prior the India-Asia collision.

Radon in drinking water poses radiation-related health risks. Investigating water-related health problems is indispensable, so the goal of the study was to determine how much radon was present in drinking water sources close to and far from the Balakot-Bagh (B-B) fault line (the site of a 7.6-magnitude earthquake in 2005) using the alpha-spectroscopy-based active method RAD-7. The sampling timeframe for the study was from May 16 to August 15, 2020. The radon level of the well water was higher, with an average value of 20.6 BqL–1. These values were 19.5 and 9.3 BqL–1 in spring and surface waters, respectively, although they were 7.7 and 5.5 BqL–1 far away from the fault line, respectively, while in well water its content (activity) was 14.9 BqL–1. The mean values for all water sources far and close from the fault line were 9.3 and 16.5 BqL–1, respectively. The value close to the fault line exceeds the maximum contamination limit recommended in the United States of 11.1 BqL–1, although the values far from the fault line were within limits. The doses determined from the radon levels of spring, well, and surface waters were 0.053, 0.056, and 0.025 mSv per year, respectively, and the mean dose of overall water-borne radon was 0.045 mSv. Based on regional comparisons, the mean radon concentrations in the drinking water sources for this study were higher than in Romania, Turkey, Italy, Poland, and India.

Exquisitely exposed Cambrian carbonates with exceptional thickness in North China offer a unique opportunity for studying the biota evolution and Earth's history. Here we characterize Cambrian oncoids by integrating petrological, geochemical, and isotopic analyses in order to unravel their genesis, assess the role of detrital fractions, and reconstruct the paleoenvironment of these ancient strata. The presence of nanosphere, microbial fossils, and relics of extracellular polymeric substances enables us to infer an important role of the microbial consortium in the origin of oncoids. These interpretations are also reinforced by fluorescence microscopy, ultraviolet excitation, and Raman spectral signature. Likewise, the depleted values of delta 13C isotopes (-1.11 to -0.46 parts per thousand) strongly support a significant input of microbial relics in the formation of oncoids. The geochemical modeling of trace and rare earth elements (REEs) advocates for oxygenated conditions in surface waters in North China during the Cambrian. Geochemical and isotopic data also reveal that oncoids are influenced by siliciclastic detrital contamination and stress the negligible role of diagenetic processes. These results provide evidence that oncoids can represent a reliable proxy of palaeoceanographic changes in the early history of Earth. (c) 2024 Elsevier B.V. All rights reserved.

The Jijal Complex is considered one of the largest Neo-Tethyan remnants in the intra-oceanic Cretaceous-Palaeogene Kohistan Arc of Pakistan. This complex largely consists of gabbros, peridotites, and chromitites. Previous studies documented the genesis of gabbros and chromitites in detail; however, detailed geochemistry and magma genesis were lacking. In this investigation, we present whole-rock geochemical and platinum group elements (PGEs) data of Jijal peridotites (dunites and harzburgites). The objectives of this study are to elucidate magmatic processes and tectonic regimes involved in the formation of peridotites, factors influencing the concentration and dispersion of PGEs in them, and their tectonic evolution. The investigated peridotite samples are depleted in magmaphile major elements (Al2O3: 0.23-0.57, TiO2: 0.01-0.04, and CaO: 0.08-0.69 wt%), relative to the primitive mantle values, reflecting melt-rock interaction during their magmatic evolution. In addition, rare-earth element (REE) contents in harzburgites are relatively higher compared to the dunites; however, both rock types exhibit depletion with respect to the chondrite-normalized values. The obvious negative anomalies of Nb, Zr, and enriched LREE and large ion lithophiles collectively substantiate their association with depleted arc-type mantle components, metasomatism, and melt/fluid-rock reactions after partial melting episodes. Bulk-rock and geochemical modelling of PGEs data of the peridotites suggest their shallow depth spinel-bearing depleted heterogeneous mantle source and generation from refractory mantle residuum along with boninitic signatures in a supra-subduction zone (SSZ). The PGE's geochemistry additionally reveals that partial melting, fractionation, metasomatism, and sulphur under-saturation were the key factors that controlled the concentration and distribution of PGEs in the studied rocks. The boninitic features of the Jijal peridotites are equated with intraoceanic fore-arc followed by subduction initiation, and melt-rock reactions in a hydrated forearc mantle, indicating robust evidence of mantle depletion and pervasive refertilisation in an embryonic Neo-Tethyan arc system. Tectonically, the investigated rocks encapsulate vestiges of the Cretaceous Tethyan Ocean and record multifaceted history from boninitic to slab-proximal island arc affinity in compliance with an intraoceanic SSZ fore-arc regime coherent with the subduction inception.

The Carnian Pluvial Episode (CPE) fingerprints global environmental perturbations and biological extinction on land and oceans and is potentially linked to the Wrangellia Large Igneous Province (LIP). However, the correlation between terrestrial environmental changes and Wrangellia volcanism in the Ordos Basin during the CPE remains poorly understood. Records of negative carbon isotopic excursions (NCIEs), mercury (Hg), Hg/TOC, and Hg enrichment factor (HgEF) from oil shales in a large-scale terrestrial Ordos Basin in the Eastern Tethys were correlated with marine and other terrestrial successions. The three significant NCIEs in the study section were consistently correlated with those in the CPE successions of Europe, the UK, and South and North China. The U-Pb geochronology indicates a Ladinian-Carnian age for the Chang 7 Member. A comprehensive overview of the geochronology, NCIE correlation, and previous bio- and chronostratigraphic frameworks shows that the Ladinian-Carnian boundary is located in the lower part of Chang 7 in the Yishicun section. HgEF may be a more reliable proxy for tracing volcanic eruptions than the Hg/TOC ratio because the accumulation rates of TOC content largely vary in terrestrial and marine successions. The records of Hg, Hg/TOC, HgEF, and NCIEs in the Ordos Basin aligned with Carnian successions worldwide and were marked by similar anomalies, indicating a global response to the Wrangellia LIP during the CPE. Anoxia, a warm-humid climate, enhancement of detrital input, and NCIEs are synchronous with the CPE interval in the Ordos Basin, which suggests that the CPE combined with the regional Qinling Orogeny should dominate the enhanced rate of terrigenous input and paleoenvironmental evolution in the Ordos Basin.

A combined study of whole-rock geochemical and Sr-Nd isotopic data, and zircon U-Pb geochronological and Hf isotopes has been carried out for several Neoproterozoic intrusions, including the Lung Thang, Posen and Sin Quyen in the Phan Si Pan Zone, northwest Vietnam to constrain their age, petrogenesis and tectonic implications. The Lung Thang and Posen intrusions, mainly composed of granodiorite, were formed at 803-777 Ma and are characterized by moderate SiO2 (64.43-66.65 wt.%), and K2O (4.05-4.89 wt.%), with A/CNK and A/NK values of (0.94-1.03) and (1.72-2.11), respectively. They have negative whole-rock epsilon Nd(t) (-6.16 to -3.73) and zircon epsilon Hf(t) values (-7.9 to -4.1), which suggest that the Lung Thang and Posen intrusions were generated by partial melting of ancient, K-rich crustal rocks. The Sin Quyen intrusion, occurring as dykes, is composed of monzodiorite and was emplaced at 742 +/- 3 Ma. The Sin Quyen intrusion has high alkalies (K2O+Na2O = 7.42-7.47 wt.%), and low MgO (<1.31 wt.%) and Ni (6.55-6.93 ppm), with A/CNK and A/NK values of (0.67-0.68) and (1.64-1.68), respectively. Their whole-rock epsilon(Nd)(t) and zircon epsilon(Hf)(t) values are -6.15 to -5.92 and -5.8 to + 8, respectively. These geochemical characteristics suggest that the Sin Quyen intrusion was produced by the partial melting of ancient crustal sources mingled with mantle-derived components. Geochemically, the Lung Thang, Posen and Sin Quyen intrusions are medium- to high-K, calc-alkaline in nature and show enrichment in LILE (Th, U, K, Rb) and LREE, and strong negative anomalies of Nb, Ta, and Ti. Such geochemical characteristics suggest that they formed in a subduction-related tectonic environment. The geochronological and geochemical correlation of these intrusions with those along the southwestern margin of the Yangtze Block in South China suggests that the Phan Si Pan zone in northwestern Vietnam is a constituent of the SW Yangtze Block. Additionally, these intrusions show a significant correlation with other contemporaneous magmatic rocks in the northeast Indochina Block, Lhasa Block, the northwestern margin of Greater India as well as those in Seychelles and northern Madagascar. This correlation suggests a similar history and synchronous episode of crustal growth/recycling in an Andean-type arc system along the western and northern margin of the Rodinia supercontinent during the Neoproterozoic.

The Bubin Cu-Pb polymetallic deposit in Gilgit-Baltistan, Pakistan, is a well-known vein-type ore deposit located in the Kohitan-Ladakh island arc. Due to its significant economic importance as the most important deposit type in the Kohistan-Ladakh island arc, a comprehensive study on its ore genesis, fluids evolution, and genetic classification not only shed new light on our understanding the formation of such polymetallic deposit at a typical intra-oceanic arc, but also of help for the mineral exploration. Here, we present the results from electron probe micro-analyzer, fluid inclusions, Raman spectroscopy, and isotopic studies (O-H-S-Pb) to gain insights into the source of ore-forming fluids and materials, as well as the genetic-type and mechanism of ore precipitation for the Bubin deposit. The mineralization processes were divided into three main stages: Stage I (quartz-pyrite), Stage II (quartz-sulfide), and Stage III (quartz-carbonate). Stage II further comprised two sub-stages: IIa (quartzchalcopyrite-magnetite) and IIb (quartz-galena-fahlore). The ore-forming fluids exhibited high to moderate temperatures (154-540 C-degrees) and varying salinities (0.35-44.30 wt% NaCl) throughout the stages. Stage I fluids displayed critical behavior with high temperature and low salinity, and their isotopic signatures suggested a magmatic origin. Subsequently, the ore-forming fluids gradually evolved from primary magmatic origin to the mixing of meteoric water, as demonstrated by oxygen and hydrogen isotopic values (delta(18)Ofluid = -1.34 to 6.29 %o, delta D = -112.4 to -76.1 %o). The delta S-34 values (-2.92 to 6.52 %o) and Pb isotopic ratios (Pb-208/Pb-204 = 39.06 to 40.93, Pb-207/Pb-204 = 15.72 to 15.99, and Pb-206/Pb-204 = 19.44 to 20.80) suggested a deep magmatic source for the ore-forming fluid, with metals primarily derived from the upper crust, likely associated with the Ladakh Batholith. Fluid boiling and maxing are the dominant mechanisms for ore mineral precipitation. Additionally, the high to moderate temperature and salinity, presence of solid-bearing and vapor rich inclusions, a Co/Ni ratio > 1, the Ni-As-Co diagram, and O-H-S-Pb isotopic evidence collectively support the classification of the Bubin Cu-Pb polymetallic deposit as an intrusion-related porphyry-style magmatic hydrothermal deposit.

The present work has been accomplished to carry out a detailed study of the characteristics of the Early Jurassic Datta Formation of Trans-Indus Ranges, Pakistan. The discovery of Saib well-1 (Gas and condensate discovery from Jurassic limestone) in the study basin takes an active interest in carrying out extensive exploration activities in the same basin. Jurassic rocks especially Datta Sandstone and Samana Suk Limestone are acting as good reservoirs. The study unit consists of variegated sandstone interbedded with siltstone, carbonaceous clay, and shale and coal stringer. For the current work, two stratigraphic sections (Pezu and Abbo Wanda) have been measured. To examine its sedimentology, depositional environment, diagenetic settings, and reservoir characteristics, a detailed study was conducted and various laboratory techniques have been utilized. About 95 rock samples from the bottom to the top of both sections were collected, and 50 rock samples have been selected for thin section analysis and were examined under a polarizing microscope to show their mineralogical composition, diagenesis, and their reservoir characteristics. XRD (X-ray diffraction), Cathodoluminescence (CL), SEM (Scanning electron microscope) with EDS (Energy-dispersive spectroscope), and Core plug porosity and permeability analysis have been used to interpret its chemical and mineralogical composition and its reservoir characteristics, respectively. Based on field observations and thin section analysis, four depositional facies and six lithofacies have been established. The sedimentary structures, depositional facies, and lithofacies indicate that Datta Formation was deposited in a deltaic environment. Compactions, cementation, fracturing and dissolution can greatly affect the quality of reservoir rock. Based on thin section and SEM analysis, large numbers of primary pores, fracture and secondary pores were observed and connectivity between the pores is good, and at some places, these pores were filled through the authigenic clay minerals like kaolinite, mixed layers illite/smectite and chlorite that influences the reservoir characteristics. Primary pores (thin section) and secondary pores (dissolution pores) and core plug porosity and permeability data (porosity 13.23%–26.89% and permeability 0.12 to 149 mD) shows that Datta Formation has a good reservoir quality.

The putative Jambil meta-carbonatites of Swat, northern Pakistan, occur as discrete intrusions into the Proterozoic Manglaur Formation, which are difficult to be distinguished from nearby calc-silicate marble because both rock types experienced regional metamorphism during Himalayan orogenesis that resulted in similar mosaic textures and mineral assemblages. Carbonatites are often significant repositories of economic mineral resources and, therefore, are important to be distinguished from calc-silicate marble. We present new geochemical and geochronology data to distinguish between the two rock types and interpret the petrogenesis and tectonic evolution of the Jambil meta-carbonatites. Whole rock chemical data from the Jambil meta-carbonatites show characteristically high rare earth element (REE), Sr contents and lack of negative Eu anomaly, consistent with average calcio-carbonatite values worldwide and an igneous origin. More than 0.5 wt.% SrO in the meta-carbonatites and SrO > 0.15 wt.% in constituent rock forming calcite are discriminating signatures of the Jambil meta-carbonatites. Chemically, the Jambil meta-carbonatites are relatively depleted in Rb, Nb, Ta, Ti, Zr and Hf, relatively enriched in Ba, Th, Sr, and have a high LREE/HREE ratio when normalized to primitive mantle. Their carbon and oxygen isotope compositions vary from −3.5‰ to −4.3‰ and from 9.7‰ to 12.3‰, respectively. These geochemical characteristics indicate generation of the carbonatites through small degree of partial melting from a carbonated eclogitic source. In-situ , U/Pb analysis of titanite indicates that the Jambil meta-carbonatites were emplacement at 438 ± 3 Ma. When combined with regional geological observations, we interpret the emplacement of the Jambil meta-carbonatites to have taken place during the Silurian back arc extension within greater Gondwana and mark a transition from a compressional tectonic regime, brought about by collision of microcontinental blocks along the northern margin of Gondwana, to post-orogenic extension in the waning stages of the pre-Himalayan Ordovician orogeny. Finally, in-situ 208 Pb/ 232 Th monazite dates (40.3−27.6 Ma) extracted from the meta-carbonatites are consistent with the Cenozoic metamorphism of the area.

The Cu-Sb-Pb polymetallic vein deposit is hosted by metavolcanics rocks of the Gawuch Formation at the Kaldom Gol area of the northwest Kohistan arc terrain in northern Pakistan. The mineralization is closely associated with the dioritic to granodioritic rocks of the Lowari pluton, which was intruded into the Gawuch metavolcanics. Details of ore characterization and processes of ore genesis of this evidently hydrothermal mineralization are not well documented. Integrating petrographic, mineral-chemical and isotopic investigations, this study aims to comprehend the source of hydrothermal fluids, geochemical evolution, mineral inclusions and physicochemical conditions of the Cu-Sb-Pb polymetallic vein deposit in Gawuch metavolcanics in the Kohistan arc terrain in northern Pakistan. The mineralization is distinguished into three types of ore-gangue associations: Type Ia, Type Ib, and Type II. The textural study revealed two pyrite generations: (i) Py1 displaying euhedral to subhedral habits and containing scarce inclusions, and (ii) Py2 occurring as anhedral grains hosting abundant inclusions. Type Ia is characterized by Py1 associated with abundant quartz (Qz) showing comb texture, sericite (Ser), and minor chlorite (Chl). Type Ib comprises Qz + Ser + Chl and Py2, chalcopyrite (Ccp), and magnetite (Mag). Type II is represented by mosaic quartz, rhombic adularia, and bladed calcite, and the ore minerals fahlore and galena. Alteration zones composed of Qz-Ser +/- Chl and Qz-Ser-Chl, surround Type I (a, b) and Type II veins, respectively. Fahlore and galena mostly replace pyrite of Type Ia and chalcopyrite of Type Ib. In addition, malachite, azurite, hematite and covellite occur as secondary (supergene) minerals. The Co/Ni ratios (>1) of Kaldom Gol pyrites suggest that the ore-forming fluids were hydrothermal in origin and Py1 and Py2 solidified at 221-304 degrees C and 225-261 degrees C, respectively. The LA-ICP-MS time-resolved depth profiles confirm the existence of sphalerite, and chalcopyrite inclusions in pyrite (Py1 and Py2) and millerite, bravoite, vaesite, Au-tellurides, native Au and galena inclusions in chalcopyrite and fahlore. Sulfur isotope compositions of pyrites (834S = Py1,-0.58 to +2 %o; 834S = Py2,-0.24 to +2.04 %o) indicate that the ore-forming fluids were derived from magmatic source (s). The mineral assemblage, hydrothermal alterations, textures, temperature and 834S of pyrites suggest that the Cu-Sb-Pb polymetallic mineralization at Kaldom Gol represents an intermediate-sulfidation type of epithermal deposit.

The Juji Nala massive sulfide deposit, hosted in the Chota Pani meta-volcanic rocks of the Kohistan-Ladakh Arc, northern Pakistan, has experienced textural and compositional changes due to metamorphism. This study integrates detailed petrographic and mineral chemical investigations to understand the formation of the original deposit and its subsequent modification due to metamorphism and deformation. The study reveals three distinct types of pyrites: a fine-grained disseminated type (Py1), an anhedral type with cataclastic texture and abundant inclusions of other minerals (Py2a), and an anhedral to euhedral type with scarce micro-inclusions (Py2b). The chalcopyrite is fine to medium-grained and forms intergrowth textures with pyrrhotite, Py2a, and Py2b. Marcasite-pyrite aggregates have replaced pyrrhotite and pyrite, whereas chalcopyrite has remained unaffected. Py1 shows a high Co/Ni ratio (> 1) and low Ni content (avg = 76 ppm), suggesting its crystallization from felsic magma-derived ore-forming fluids at temperatures between 366 and 397 °C. The Juji Nala ores have undergone at least four distinct phases of metamorphism, including the cataclastic Py2a formed under greenschist metamorphism, contact metamorphism (upper greenschist to lower amphibolite facies) due to igneous intrusion, thermal annealing, and late-stage cataclasis and retrograde metamorphism during exhumation. In contrast to pyrite, pyrrhotite and chalcopyrite display ductility, and this explains why the pre-metamorphic features of these two minerals were obliterated during metamorphism. This study provides insights into the formation and modification of the Juji Nala deposit, highlighting the importance of considering metamorphic changes in mineral deposits.

Carbonatites are proven significant repositories of several critical and strategic elements such as rare earth elements, niobium, thorium, and uranium. Owing to their economic significance, mapping of carbonatites and associated mineral deposits has occupied prominent place in mineral resource exploration programs. In this study an integrated approach was developed to map carbonatite and related mineral deposits in the Loe-Shilman, Northwest Himalaya of Pakistan, using remotely sensed advance space-borne thermal emission and reflection radiometer (ASTER) multispectral data and visible near infrared and short-wave infrared (VNIR-SWIR) spectral characteristics of minerals in these deposits. Several image enhancement techniques, including band ratio (i.e., B4/B3), principal component and minimum noise fraction transformation (PC6 and MNF5, respectively) helped in highlighting the targeted rocks. The results demonstrate the suitability of ASTER data for discriminating carbonatite related mineral deposits from other surrounding lithologies. Results obtained from these methods were validated through field observations in the area and further confirmed through petrographic and chemical analyses of collected specimens. Field data have also served as training data to perform a supervised classification, allowing further improvement of the mapping results. Moreover, the obtained results from the techniques used for exploring carbonatites and related mineral deposits were stacked together for comparison with each other, to check their sensitivities, and assess their efficiency and accuracy. Generally, all these methods successfully highlighted carbonatites and related mineral deposits; however, when used integratively they exhibit higher degree of accuracy, and has proven to be relatively rapid and cost-effective.

The Kohistan Arc preserves an exquisite and ideal petrogenetic record for studying mafic magmatism in an arc environment. Here we report the geochronological, mineralogical, and geochemical data of the gabbros from the Chilas Complex of Kohistan in order to understand their genesis, timing, role in crustal thickening, and tectonic evolution in Neo‐Tethys. The mineral composition of orthopyroxene (Opx) in gabbros displays transitional to metamorphic behaviour with high amount of Al 2 O 3 (0.59–2.66 wt.%), suggesting the influence of subsolidus re‐equilibration during cooling or magmatic crystallization. Thermobarometric constraints propose the crystallization of Chilas gabbros around 892–985°C and ≤1.5 GPa pressure coupled with high H 2 O content (5.6%–7.7%). Geochemical modelling and isotopic peculiarities such as ( 87 Sr/ 86 Sr)i (0.000018–0.704140) and 206 Pb/ 204 Pb (18.526–18.554) suggest that the source of gabbros was depleted, likely controlled by peridotite melts and experienced insignificant crustal contamination. Relatively lower ratios of Nb/Yb (0.89–3.32) and TiO 2 /Yb (0.14–0.79) imply that the garnet was not a residual phase during the partial melting of a mantle source. The Chilas gabbros with depletion in Nb and Ta, enrichment in light rare earth element (LREE)s, the lower Ce/Pb ratios, plot of Th/La versus Th, and negative anomalies of Eu provide a consistent clue regarding the negligible participation of recycled components. Zircon U–Pb concordant ages of 83–86 Ma indicate the timing of emplacement and a Cretaceous magmatic event in the Chilas Complex. We infer that the Cretaceous magmatic flare‐up is a significant crustal growth event of Kohistan and consider the underplating of mantle‐derived magmas as one of the primary reasons for the crustal thickening based on zircon Hf isotopic signatures. The average chemical composition of Kohistan Complex provides support for the generation of andesitic magmas in arcs and the “andesite model” of continental crustal growth. We propose the similar petrogenesis for the Nidar, Kargil, and Chilas gabbros linking the formation of these variants within Neo‐Tethys based on identical magmatic records.

The Sapat Complex in Northern Pakistan contains remnants of the northern Neo-Tethys Ocean, presently exposed along the Indus Suture Zone. The mantle peridotites of the Sapat Complex include harzburgites, dunites, and subordinate lherzolites. Harzburgites are the dominant peridotite variety over dunites. The dunites are hosted by harzburgites and occur exclusively as 'envelopes' surrounding chromitite pods. The podiform chromitites show disseminated, banded, and massive textures. Chromitites exhibit variable Cr# [Cr/(Cr + Al)] and Mg# [Mg/(Mg + Fe2+)], which range from 0.76 to 0.77, and from 0.64 to 0.66, respectively, while TiO2 contents are <0.2 wt.%. These features perhaps reflect crystallization of the chromian spinel from a boninitic magma. Similarly, chromian spinel in peridotites manifest a wide range of Cr# and Mg#, from 0.49 to 0.83 and 0.41 to 0.57, respectively, and are characterized by very low TiO2 values, averaging at 0.1 wt.%. Chromian spinel of chromitites and peridotites of the Sapat Complex have also very low Fe3+# (<0.01), which indicate their crystallization under low oxygen fugacities. The platinum group elements (PGE) distributions show high (Os + Ir + Ru)/(Rh + Pt + Pd), very low Pd/Ir values, and are defined by a prominently fractionated chondritic normalized PGE pattern, hence, this deposit is a typical example of an ophiolitic chromitite. The studied peridotites are highly depleted in PGE compared to chondritic values. The Pd-N/Ir-N values, averaging to 1.5 in dunites are unfractionated, while PGE spidergrams of harzburgites and lherzolites depict minor positive slopes, a minor positive Ru anomaly, and have average Pd-N/Ir-N values of 2.3 and 2.4, respectively. Furthermore, the harzburgites, dunites, and lherzolites display generally flat chondritic and primitive mantle normalized PGE patterns, and therefore, are nearly identical to highly depleted mantle peridotites. The mineralogical and PGE geochemical imprints of Sapat Complex chromitites and peridotites establish a strong affinity to supra-subduction zone ophiolites. Moreover, calculated parental melts of the chromitites and various geochemical discrimination diagrams elucidate that the chromitites were derived from boninitic magma produced by melting of depleted mantle peridotites in an oceanic arc, characterized by low oxygen fugacity, similar to a supra-subduction zone tectonic setting. This research highlights the use of mineralogy and geochemical compositions of chromitites and peridotites to reveal deep magmatic processes in a supra-subduction zone environment.

The tight gas reserves in the Hangjinqi area are estimated at 700 × 109 m3. Since the exploration of the Hangjinqi, numerous wells are already drilled. However, the Hangjinqi remains an exploration area and has yet to become a gas field. Identifying a paleo-depositional framework such as braided channels is beneficial for exploration and production companies. Further, braided channels pose drilling risks and must be properly identified prior to drilling. Henceforth, based on the significance of paleochannels, this study is focused on addressing the depositional framework and sedimentary facies of the first member (P2x1) of the lower Shihezi formation (LSF) for reservoir quality prediction. Geological modeling, seismic attributes, and petrophysical modeling using cores, logs, interval velocities, and 3D seismic data are employed. Geological modeling is conducted through structural maps, thickness map, and sand-ratio map, which show that the northeastern region is uplifted compared to northwestern and southern regions. The sand-ratio map showed that sand is accumulated in most of the regions within member-1. Interval velocities are incorporated to calibrate the acoustic impedance differences of mudstone and sandstone lithologies, suggesting that amplitude reflection is reliable and amplitude-dependent seismic attributes can be employed. The Root Mean Square (RMS) attribute confirmed the presence of thick-bedded braided channels. The results of cores and logging also confirmed the presence of braided channels and channel-bars. The test results of wells J34 and J72 shows that the reservoir quality within member-1 of LSF is favorable for gas production within the Hangjinqi area.

The upper mantle section of the Dargai ophiolite along the Indus Suture Zone, also known as the Main Mantle Thrust of northern Pakistan, consists mainly of clinopyroxene-bearing (Cpx)-harzburgites, depleted harzburgites, and dunites. Here we document a two-stage origin for these ultramafic rocks using new mineral and whole-rock geochemistry, integrated with Re-Os isotopic data of these upper mantle peridotites. Chromian spinel in the Cpx-harzburgites have significantly lower Cr# values (15.2-20.7) than the depleted harzburgites (38.4-75.2) and dunites (75.0-81.9). The Cpx-harzburgites are characterized by high average Al2O3 (2.04 wt%), CaO (2.26 wt%), sigma(REE) (24.3 ppb), and Os-187/Os-188 values ranging between 0.12495 and 0.12997. In contrast, the depleted harzburgites and dunites are characterized by lower average Al2O3 (0.51 wt% and 0.14 wt%, respectively), CaO (0.68 wt% and 0.19 wt%, respectively), and sigma(REE) (3.41 ppb and 0.92 ppb, respectively). The Os-187/Os-188 of the depleted harzburgites range between 0.11699 and 0.12612, values that are less radiogenic than those of the Cpx-harzburgites. The mantle-normalized trace element patterns of the Cpx-harzburgites reflect low degrees of partial melting (similar to 10-15%), whereas those of the depleted harzburgites and dunites record somewhat higher degrees of partial melting (similar to 15-23% additional melting of the Cpx-harzburgites). The low degree of melting, coupled with low degrees of melt extraction, therefore point to a spreading center at amid-ocean ridge (MOR) or in a distal forearc basin. In contrast, the depleted harzburgites and dunites formed during the second stage of melting and related refertilization, and were clearly linked to a supra-subduction zone (SSZ) setting. The Re-Os isotopic compositions of the Dargai Complex peridotites provide model ages of ca. 250 and ca. 450 Ma recording pro-tracted tectonic events in close association with the geodynamic evolution of the Neo-Tethyan, Rheic, and Proto-Tethyan oceans. The extremely heterogeneous Os isotopic compositions of this part of the Neo-Tethyan upper mantle reflect multiple melt production and melt extraction processes throughout its tectonic evolution.

Vertical infiltration of water plays an important role in the recharged of contaminated water and enhanced moisture content in the unsaturated porous media. The mathematical model used for such type of phenomenon is Burger's equation. Unsaturated porous media are analyzed by solving Burger's equation using the variational iterative modeling and homotopy perturbation method. When considering all moisture contents, it appears that the cumulative coefficient is unchanged. It is also shown that the soil's moisture content decreases with depth (y) and time (t). The results indicate that this method is very efficient and can be useful to solve large-scale problems that arise in civil engineering, geology, material science, and fossil fuel problems.

This study reports new occurrence of niobium mineralization from the Loe-Shilman carbonatite complex, NW Pakistan. The complex is predominantly comprised of calcite carbonatite, intruded by dolomite carbonatite, and minor late-stage carbonatite veins, intruding the earlier two varieties. Pyrochlore group minerals, which are the major Nb phases in the carbonatites and overlying supergene laterite, manifest numerous textural and compositional discrepancies. Pyrochlores observed in calcite and dolomite carbonatites of the complex are typified by oscillatory zoning, and are compositionally Ca-Na-pyrochlore, and therefore, illustrating crystallization under primary magmatic conditions. However, relatively Ta poor (2.42-5.11 wt%) and Nb rich (60.04-62.14 wt%) pyrochlores preserved in dolomite carbonatite are reflecting a more evolved nature of the dolomite carbonatite compared to Ta rich (6.89-10.11 wt%) pyrochlore of the calcite carbonatite. In addition, pyrochlores of the late-stage carbonatite veins record patchy zonation and are characterized by A-site vacancies, likely due to leaching of Na and Ca, and enrichment of Ba-REE-Sr during hydrothermal alteration by a relatively low pH, Na and/or Si poor fluids. Similarly, intensively patchy zoned, porous and Fe3+ bearing A-site deficient bariopyrochlore in supergene laterite are produced by complete leaching of Ca and Na from A-site, and by partial replacement of strongly-bounded Nb at B-site by Fe3+ during supergene conditions.