1. Introduction
Manganese is a key element of the ferroalloy metals which is mainly used in steel making, and other metallurgical, battery and chemical industries. It is mostly used in the form of ferromanganese (FeMn) and silico-manganese (SiMn) and various compounds such as MnSO4, MnCl2, KMn, etc. in various industries. In the steel industry, it is used for the removal of oxygen and sulfur, which imparts hardness, malleability, and tenacity to steel. Steel made of ferromanganese and silico-manganese is used in construction and transportation machinery (Siddiquie et al. 2015; Rehman et al. 2020). The chemical grade of Mn is used in the production of chemicals, batteries, glass, plant food, paints, and pigments, as well as in the textile industry. It is also used as a water purifier, catalyst and as a carrier of oxygen for chemical looping combustion (CLC) (Mehdilo and Irannajad 2014; Haider et al. 2016). Globally, most of the Mn (90-95%) produced annually (with Mn content greater than 40 %) is used in the steel industry as a deoxidizer and desulfurizer. The remaining (5-10%) is consumed by other sectors, such as the chemical, paint, fertilizer, batteries and glass industries (Lasheen et al. 2009).
World over, Mn-deposits have been formed in various tectonic settings which include continental sedimentary sequences, as well as ophiolites. These deposits can be divided into three broad categories (1) hydrothermal (2) hydrogenous and (3) digenetic/biogenetic-bacterial deposits (Polgári et al. 2012; Öksüz 2011). Hydrothermal deposits form through direct precipitation from hydrothermal solutions at low temperatures (Hein et al. 1997; Ingram et al. 1990). These deposits are typically strata bound and laminated or can exist as irregular bodies and epithermal veins. They are discovered in both present-day and past marine environments, located near spreading centers or intraplate seamounts, as well as in island arc settings associated with subduction (Polgári et al. 2012; Baba et al. 2003; Öksüz and Okuyucu 2014). Hydrogenous deposits are composed of ferromanganese crusts, which are rich in amorphous iron compounds and usually depleted in Mn minerals. It slowly precipitates from seawater from microbial activity at rates of 2 to 10 mm per Ma on the seafloor (Öksüz 2011; Jach and Dudek 2005; Toth 1980). Hydrogenous deposits are characterized by high trace element concentrations, particularly Ni and Cu and a low Mn/Fe ratio (~1) (Hein et al. 1997, 1996; Usui and Someya 1997; Usui and Nishimura 1992; Ingram et al. 1990; Toth 1980). Diagenetic/biogenetic-bacterial manganese deposits are formed in nodules and precipitate with the effect of hydrothermal solutions in the form of Mn-carbonate mineralization due to oxidation of organic matter (Polgári 1991; Polgári et al. 2012; Öksüz 2011). Although the hydrothermal and diagenetic deposits are characterized by high Mn/Fe ratios and low trace metal contents (Hein et al. 1996, 2013) but these can be distinguished on the basis of their morphology, tectonic setting and growth rates (Kuhn et al. 1998; Choukrad et al. 2022).
In Pakistan, low to medium-grade Mn-deposits, associated with a continental sedimentary sequence, are reported in Chura Gali, Galdanian and Kakul from the Hazara region of Khyber Pakhtunkhwa Province, (Shah and Moon 2004, 2007). Similarly, Mn deposits that are associated with ophiolitic rocks are reported from North Waziristan (Shah and Khan 1999; Shah and Moon 2007), Lasbela-Khuzdar, Zhob (Naseem et al. 1997; Khan et al. 2020) and the Bela area (Narijo et al. 2019).
2. Regional Geology
Northern Pakistan has two major regional-scale tectonic faults, namely the Main Mantle Thrust (MMT) /Indus Suture Zone (ISZ) in the south and the Main Karakorum Thrust (MKT) in the north (see Figure 1). These two thrust faults have geologically divided northern Pakistan into three separate tectonic domains from north to south, i.e. Karakoram block (KB), the Kohistan Island Arc (KIA) and the Indian Plate (IP) (see Figure 1) (Tahirkheli 1979; Bard 1983; Treloar 1989; Khan et al. 1993; Burg 1996; Kazmi and Jan 1997; Searle et al. 1999). The MMT/ISZ defines the tectonic boundary between the KIA and the IP in the south. During the Paleogene, it developed as a result of the closing of the Neo-Tethys Ocean and eventual collision of the northern Indian Plate edge with the Kohistan and Ladakh Arc (Molnar and Tapponnier 1975; Tahirkheli 1979; Klootwijk et al. 1992). The MMT/ISZ is not a single fault but a sequence of faults with varying ages and tectonic histories (Searle et al. 1999; DiPietro et al. 2000). A thick zone of sheared ophiolitic melanges appears along the MMT/ISZ (see Figure 1). From east to west along the MMT/ISZ, these are the Mingora, Charbagh and Shangla ophiolitic melange zone, Malakand and Dargai ophiolitic melanges and the Nawagai ophiolitic melange (Kazmi et al. 1984; DiPietro et al. 1991; 2008). These ophilitic melanges are characterized by a variety of highly deformed ophiolitic rocks that have undergone varying degrees of metamorphism (Kazmi and Jan 1997; Ahmad and Jehan 2006). Serpentinite, dunite, lherzolite, gabbro, basalt, and sedimentary rocks like limestone and chert (pelagic sediments) are the predominant rocks of these melange zones. These rocks have undergone varying degrees of mixing and metamorphism as a result of the numerous tectonic processes that occurred during the development of the suture zone (Robertson 2000). These melanges also contain a range of valuable metallic and non-metallic mineralization including chromite, manganese, platinum group elements (PGEs), nickel, emerald and nephrite, etc. (Ahmad and Jehan 2006).
Figure 1. Geotectonic map of northern Pakistan showing the location of the study area (after DiPietro and Pogue 2004)
2.1. Geology of Study Area
The study area lies in the Toposheet No. 38N/06 of the Geologic Survey of Pakistan. It is located in the vicinity of Inzari Village in the Mohmand District which is easily accessible from Peshawar, the capital city and a district of Khyber Pakhtunkhwa (KP) Province (see Figure 2). The Mohmand District shares its borders with the Bajaur District in the north, the Khyber District in the south, Malakand and Charsadda districts in the east and the Peshawar District in the southeast. Geologically, the study area is located in the Nawagai ophiolitic melange (DiPietro et al. 1991; 2008), which is a part of the Indus suture melange and is lying in the western most part of the MMT/ISZ (DiPietro and Pogue 2004). The dominant lithologies of the Nawagai ophiolitic melange are marble, dunite, serpentinite, greenstone, grey to black and green phyllites while talc-carbonate schist occurs as a subordinate lithology (Aslam et al. 2006). Cryptocrystalline meta-chert showing grey to reddish-brown colouration, along with clay minerals and at places marble is hosting the Mn mineralization in the Mohmand area (see Figure 3). The manganese ores are identified by their black colour and silvery luster in the field. These ore bodies are scattered in the form of irregular massive lenticular bodies with varying dimensions (see Figure 3). At places, the ores and host rocks (meta-cherts) contain cross-cutting fractures filled veins of quartz and carbonates. These ores and their host rocks are fragmented, folded, faulted and sheared suggesting that the metamorphism/deformation has occurred after the formation of these ores.
Figure 2. Geological map of the Mohmand District taken and modified from Aslam et al. (2006), showing the location of the study area.
Detailed field work was carried out in the study area to collect representative samples from the Mn-ores and the host rocks, and also to identify the various field features, as shown in Figure 3. During fieldwork, 15 fresh looking samples of Mn-ores and 7 samples of host rocks (meta-chert) were collected for the experimental work in the Geochemistry Laboratory of the National Centre of Excellence in Geology (NCEG), University of Peshawar, Pakistan. These samples were crushed and pulverized to -200 mesh size, using a tungsten carbide cup mill (FRITSCH PULVERISETTE 9). The open-acid digestion technique after Jeffery and Hutchison (1986) using PTFE Teflon beakers was adopted whereby known weights of Mn-ores powdered samples were treated with HCL (10ml) and HF (5ml) for the complete digestion and known weights of host rock powdered samples were treated with HF: HNO3:HClO4 in the ratio of 7:3:1 for their complete digestion. The digested sample solutions of both ores and host rocks were analyzed for major oxides (i.e. MnO, Fe2O3, CaO, MgO, Na2O and K2O) and trace elements (i.e. Co, Cr, Cu, Cd, Pb, Ag and Ni) using Atomic Absorption Spectrometer (AAS) (Perkin Elmer 7000, equipped with graphite furnace) under the standard calibrated conditions. The analysis of SiO2, TiO2, P2O5, and Al2O3 was carried out using a Pye Unicam UV/visible spectrophotometer as described by Jeffery and Hutchison (1986). The loss on ignition (LOI) was determined gravimetrically by heating the known weight of powdered samples of both ores and host rocks in a muffle furnace at 1200°C for four hours.
Petrographically, the Mn-ores and host rock samples were studied using polished thin sections under polarized and reflected light microscopy. For the identification of different Mn-bearing phases and gangue minerals X-ray diffraction (XRD: JEOL-JDX-3532) and scanning electron microscopic (SEM: JEOL-JSM-IT-100) techniques were carried out at the Centralized Resource Laboratory (CRL), and NCEG, University of Peshawar, respectively.
Figure 3. Field photographs of manganese ores: (A & B) tectonized bodies of manganese enclosed in the host rock (meta-chert), (C) Manganese ores are cross-cut by quartz and calcite veins, (D) Hand specimen showing pull apart texture where fractures are filled with quartz and carbonates, (E) Intense shearing and foliation in shear zones, (F) Lensed shaped manganese ore enveloped by host rock.
4. Results and Discussion
4.1. Petrography and Mineralogy
The XRD analysis of selected samples of the manganese ores revealed that two types of Mn-ore minerals, such as Mn silicate-oxide (braunite) and Mn-oxide (pyrolusite), are present in these ores along with quartz, calcite and hematite as accessory minerals (see Figure 4). Braunite, being the principal Mn-bearing phase, is in various shapes which range from microcrystalline to subhedral to euhedral coarse-grained. Microcrystalline braunite is intermixed with cryptocrystalline quartz, while the coarse-grained are interlocked having planar to sutured contacts, and the ore minerals are cross-cut by the quartz and calcite veinlets (see Figure 5a). Anhedral to subhedral, spindle and fibrous shaped pyrolusite grains are present in association with braunite and cryptocrystalline quartz (see Figure 5b). Pyrolusite also occurs as fractures filled phase (see Figure 5a and e). Cryptocrystalline quartz, a major accessory mineral, is generally enclosing the braunite, pyrolusite and piemontite (see Figure 5b, f and d). Piemontite and pyrolusite are replacing braunite at places (see Figure 5e and g). Fine-grained hematite is found in dissemination (see Figure 5h). In general, the coarse-grained quartz is found in the form of veins while the cryptocrystalline quartz is either enclosing or enclosed in the braunite (see Figure 5h and i). The petrographic features suggest that there could be two stages of formation of ore phases within the studied Mn-ores. The early stage is represented by massive braunite and minor pyrolusite minerals, while the late stage is characterized by replacement phases such as pyrolusite, piemontite and hematite. Braunite may have been altered to pyrolusite and hematite through chemical weathering and leaching due to silica removal and re-oxidation of Mn in low-grade surface environments (Shaif et al. 2020; Safarov et al. 2024) while the piemontite may have been formed by the alteration of braunite during medium to high-grade metamorphism (Sinisi et al. 2018; Marescotti and Frezzotti 2000).
The meta-cherts, generally hosting the Mn-ores, are mainly composed of microcrystalline to cryptocrystalline quartz / chalcedony and a lesser amount of hematite. The pseudomorphs of radiolarian chert, occasionally replaced by microcrystalline quartz, hematite, carbonates and clay minerals, are also noticed.
Figure4. XRD graph showing the 2θ position of braunite, pyrolusite, hematite, quartz and calcite in the Mn-ores of the study area.
Figure 5. Photomicrographs (plane polarized: a-c; reflected light: d-f and SEM images: g-i) showing (a) veinlets of quartz and calcite cross-cutting the braunite grains while pyrolusite is present as fracture filled phase, (b) coarse-grained pyrolusite and piemontite are replacing braunite while spindle and fibrous shape pyrolusite is also visible (c) coarse-grained braunite is enclosed in cryptocrystalline quartz, (d) piemontite and braunite are enclosed in cryptocrystalline quartz, (e) pyrolusite occurs as fractured filled phase within cryptocrystalline quartz, (f) intermixing of braunite, pyrolusite and cryptocrystalline quartz, (g) pyrolusite is replacing braunite while quartz is also enclosed in braunite, (h) fine-grained hematite and quartz grains are present within braunite, (i) cryptocrystalline quartz veinlets are cross-cutting the Mn-minerals.
Abbreviation: Bnt: braunite; Pyl: Pyrolusite; Qtz: Quartz; Hem: Hematite; Pmt: Piemontite; Cal: Calcite.
4.2. Geochemistry
The representative samples of the studied Mn-ores and host rocks (i.e. meta-chert) have been analyzed for major and trace elements and the results are presented in the Tables 1 and 2, respectively. According to the classification of Dorokhin et al. (1969), the studied Mn-ores, as of having 19.08 wt% to 45.21 wt% MnO, can be considered as low-grade (<35 wt% MnO), medium-grade (35-40 wt% MnO) and high grade (>40 wt% MnO) manganese ores. Economically, the studied Mn-ores, having 31.93 wt% MnO on average, can be termed as low-grade ores as a whole (see Table 1). The Mn-ores of the study area have SiO2 contents ranging from 30.14 to 62.23 wt% (average: 48.41 wt%), TiO2 from 0.03 to 0.46 wt% (average: 0.15 wt%), Al2O3 from 1.86 to 3.87 wt% (average: 2.68 wt%), Fe2O3 from 1.42 to 5.30 wt% (average: 3.26 wt%), MnO from 19.08 to 45.21 wt% (average: 31.93 wt%), MgO from 0.11 to 2.13 wt% (average: 0.91 wt%), CaO from 3.95 to 7.96 wt% (average: 5.85 wt%), Na2O from 0.93 to 1.60 wt% (average: 1.22 wt%), K2O from 0.02 to 1.30 wt% (average: 0.73 wt%) and P2O5 from 0.02 to 0.21 wt% (average: 0.08 wt%). Among the trace elements, Co is in the range of 2-48 ppm (average: 12 ppm), Cr: 1-56 ppm (average: 19 ppm), Cu: 8-402 ppm (average: 190), Cd: 1-5 ppm (average: 3 ppm), Pb: 10-131 ppm (average: 39 ppm), Ag: 1-17 ppm (average: 9 ppm) and Ni: 1-150 ppm (average: 65 ppm). All the trace elements are highly variable in the studied Mn-ores. The Mn/Fe and Fe/Mn ratios are also having greater variation and are ranging from 7.67 to 19.39 and 0.05 to 0.13 with the average values of 10.85 and 0.09, respectively. The major oxides have been corelated with the MnO in Figure 6. It has been found that all the major oxides, except SiO2, exhibit no any correlation with MnO. However, SiO2 has well-defined positive correlation with MnO (see Figure 6a). This can be attributed to the formation of higher amount of braunite in the studied Mn-ores.
The studied meta-cherts are mainly composed of SiO2 in the range of 78.23 to 82.65 wt%, Al2O3: 4.52 to 8.41 wt%, Fe2O3: 1.35 to 4.50 wt%, MgO: 0.10 to 3.25 wt% and CaO: 2.64 to 4.17 wt% while rest of the major oxides are in very low concentrations (see Table 2). The average concentration of trace elements such as Co, Cr, Cd, Pb, Ag and Ni in the studied mata-cherts are 8 ppm, 23 ppm, 50 ppm, 3 ppm, 12 ppm, 5 ppm and 33 ppm, respectively.
It is now well established that the geochemical characteristics of various types of manganese deposits have played a major role in characterizing the ancient analogues of hydrothermal and hydrogenous manganese deposits that are formed on the modern ocean floor (Crerar et al. 1982). During the precipitation of hydrothermal solution along the mid ocean ridges, the fractionation of Mn and Fe is resulted in the low and high Mn/Fe or Fe/Mn ratios in exhalative sediments (Bonatti 1972; Bonatti et al. 1972, 1976; Shah and Khan 1999; Shah and Moon 2007; Khan et al. 2020). The ratios of Mn/Fe are ranging from 7.67 to 19.39 and Fe/Mn from 0.05 to 0.13 in the studied Mn-ores. These ratios are consistent with that of the hydrothermal exhalative Mn-deposits formed in ophiolitic sequences and along the mid-ocean ridges (Bonatti et al. 1972, 1976; Jach and Dudek 2005; Shah and Moon 2007; Jiancheng et al. 2013; Sasmaz et al. 2014). Various researchers have used major and trace elements to distinguish manganese ores of hydrothermal and hydrogenous origin (i.e. Bonatti et al. 1972; Toth 1980; Crerar et al. 1982; Adachi et al. 1986; Peters 1988; Choi and Hariya 1992; Nicholson 1992). The geochemical data of the studied Mn-ores have been plotted in the discrimination diagrams, as shown in Figure 7. Almost all the samples fall within or close to the field of hydrothermal Mn-deposits in Co/Zn vs Co+Ni+Zn diagram (see Figure 7a) of Toth (1980), Si vs Al diagram (see Figure 7b) of Crerar eta al (1982), Zn-Ni-Co diagram (see Figure 7c) of Choi and Harira (1992) while in the Mn-Fe-(Ni+Co+Cu)*10 diagram (see Figure 7d) of Bonatti (1972) and Crerar et al. (1982), the data fall in the overlapping fields of hydrothermal and diagenetic Mn-deposits.
The very low Fe/Mn ratio due to very low amount of Fe in the studied Mn-ores suggest that fractionation of Fe has occurred well before the formation of these ores (Roy 1992; Frakes and Bolton 1992; Shah and Khan 1999; Shah and Moon 2007). It is reported that the concentrations of trace elements (i.e. Cu, Zn, Ni and Co) in the modern submarine manganese deposits of East Pacific Rise and the Galapagos areas are higher than the pelagic sediments, but are much lower in the hydrothermal Mn-deposits relative to the hydrogenous Mn-deposits (Cronan 1980). This is also confirmed in the case of the studied Mn-ores (see Figure 7). The plotting of the samples of studied Mn-ores along the Ni-Zn join line in Figure 7c also confirms the relationship of the studied Mn-ores with the modern submarine hydrothermal Mn-deposits. It is now well understood that the Fe compounds are less stable than the Mn compounds, whereby the Eh and/or pH is playing an important role, therefore, the precipitation of Fe has been reported proximal and Mn distal to the vent along the sea floor spreading centers (Panagos and Varaavas 1984; Roy 1992; Frakes and Bolton 1992; Shah and Khan 1999; Shah and Moon 2004, 2007; Khan et al. 2010).
Table 1. Geochemical analysis (major oxides in wt % and trace elements in ppm) in the Mn-ores of the Mohmand area.
Table 2. Geochemical analysis (major oxides in wt % and trace elements in ppm) of the host rocks (meta-cherts) of the Mohmand area.
Figure 6. Major oxides versus MnO variation diagram of the studied Mn-ores.
Figure 7. Plotting of the geochemical data of the studied Mn-ores from Mohmand area in the various discrimination diagrams: a) Co/Zn vs Co+Ni+Zn diagram of Toth (1980); b) Al vs Si diagram of Choi and Hariya (1992); c) Zn-Co-Ni diagram of Choi and Hariya (1992); d) Mn-Fe-(Ni+Co+Cu) diagram of Bonatti et al. (1972) and Crerar et al. (1982).
4.3. Genetic Model
The Nawagai ophiolitic melange in the Mohmand District, like the other ophiolitic melanges along MMT/ISZ, are the remnants of the Neo-Tethys oceanic crust which were formed during the opening and closing of the Neo-Tethys with the later supra-subduction stage. These are later on obducted on to the Indian Plate during collision of the KIA with the Indian Plate in Late Cretaceous. The KIA was formed during the intra-oceanic subduction of the Neo-Tethys oceanic lithosphere and latter on merging with the Karakoram Plate to form an Andean type margin and finally collided with the Indian Plate (Molnar and Tapponier 1975; Tahirkheli 1979; Klootwijk et al. 1992; Arif and Jan 2006; Ullah et al. 2025).
By considering the models of Bonatti et al. (1976), Canon and Force (1983), Buehn et al. (1992), Shah and Khan (1999), Khan et al. (2020), Ullah et al. (2025), a very simple genetic model can be proposed for the formation of the Mn-ores of the Mohmand area from the hydrothermal solution along the mid-ocean ridges in the Neo-Tethys and later on obduction of these ores within the Nawagai ophiolitic melange along MKT/ISZ (see Figure 8). According to this model, during the early stage (Late Jurassic) of Neo-Tethys Ocean, a mid-oceanic ridge setting was present where the sea water was percolating through the hot oceanic basaltic crust and resulted in the formation of hydrothermal solutions. During this process, the hydrothermal solutions started leaching out the Mn, Fe, Cu, Pb, Zn, Co, and other metals from the basaltic crust. These metals enriched hydrothermal solutions started discharging and precipitating on to the sea floor. Due to change in temperature and pressure and an increase in Eh and/or pH, the various metal sulfides started precipitating along or closer to the discharge vents, while the Fe and Mn fractionation in the form of ferromanganese and manganese ores took place proximal and distal to the vent, respectively (Bonatti et al. 1976; Crerar et al. 1982; Thornton and Seyfried 1985; Sawkins,1984; Roy 1992; Shanks et al. 1995; Shah and Khan 1999, Shah and Moon 2007; Khan et al. 2020).
Considering the lower amount of Fe, higher amount of Si and higher Mn/Fe ratio in the Mn-deposits of the Mohmand area, these ores may have been formed distal to the discharge vent on the sea floor due to the early precipitation of ferromanganese ores near the source of hydrothermal solution and manganese ores distal to the source with input from the pelagic sediments within the mid-oceanic spreading center. This can be correlated with the present-day hydrothermal system within the mid-oceanic spreading centers (Roy 1992; Shah and Khan 1999; Shah and Moon 2007; Narejo et al. 2019; Khan et al. 2020). The development of mid-ocean ridges environment in the Neo-Tethys Ocean during Late Jurassic was followed by the origination of KIA by the northward double subduction during Early to Late Cretaceous. Afterwards, the closure of the Neo-Tethys Ocean and finally collision of KIA with the Indian Plate resulted in the formation of supra-subduction zone ophiolites, including the Nawagai ophiolitic melange, in northern Pakistan (Ullah et al. 2025).
The studied Mn-ores of the Mohmand area after their formation along the spreading centers were later on obducted on to the Indian Plate along the MMT/ISZ as part of the Nawagai ophiolitic melange during the subduction and later on collision of the Indian Plate with the Kohistan Island Arc. The field features such as the massive lenticular shape tectonized bodies with folding, faulting and shearing suggest that these ores and the host rocks may have undergone severe metamorphism and deformation during and after emplacement of the ophiolitic bodies in the existing position. This may have caused the recrystallization of manganese oxides and hydroxides into braunite by incorporating silica from the associated quartz (chert) during metamorphism. However, the essential geochemical characteristics of the deposits remained intact (see also Bonatti et al. 1976; Shah and Khan 1999; Khan et al. 2020). The geochemical characteristics of the studied Mn-ore bodies of the Mohmand area occurring in the Nawagai ophiolitic melange have been compared with the hydrothermal manganese deposits of other ophiolitic sequences elsewhere in the world in Table 3, for example, the Bela ophiolitic complex, Pakistan (Narejo et al. 2019); the Zhob ophiolites, Pakistan (Khan et al. 2020), the Waziristan ophiolite complex, Pakistan (Shah and Khan 1999; Shah and Moon 2007), Dehoo, ophiolitic unit, Iran (Lotfi et al. 2017), Cayirli, Ankara ophiolitic melange, Turkey (Zarasvandi et al. 2013) and Wakasas, Tokoro Belt, Hokkaido, Japan (Öksüz 2011). The studied Mn-ores of Mohmand area are very well correlated with the hydrothermal manganese deposits associated with ophiolitic sequences elsewhere in the world by having a higher Mn/Fe ratio, lower Fe/Mn ratio and lesser amount of trace elements (Table 3) as compared to hydogenous manganese deposits (Nicholson et al, 1997; Jach and Dudek 2005).
Figure 8. Hypothetical model showing the geological environment for the formation of Mohmand Mn-ores in the Neo-Tethys (modified after Ullah et al. 2025)
5. Conclusions
Manganese ores of the district Mohmand occur in the form of lenticular and irregular bodies of varying dimensions with cross-cutting quartz veins associated with cryptocrystalline meta-chert in the Nawagi ophiolitic melange zone. The ore bodies are highly sheared and fractured and these fractures are filled in by quartz and carbonates in the form of veins. Braunite is the dominant Mn-bearing phase with a lesser amount of pyrolusite and piemontite. Microcrystalline quartz, calcite and hematite occur as gangue minerals. Geochemical data suggest that the major and trace elements are highly variable in these ores and on the basis of the presence of Mn and Fe contents, these ores can be classified as high to low-grade but economically, as a whole, these ores can be considered as low-grade. The geochemical data further suggest that these ores have been formed due to the precipitation of hydrothermal solution distal to the discharge source (vent) with some input from the pelagic sediments on the sea floor within the spreading centers in the Neo-Tethys Ocean during Late Jurassic. These ores are then obducted on to the Indian Plate as part of the Nawagai ophiolitic melange due to the subduction and later on collision of Indian Plate with the KIA along the MMT/ISZ during Late Cretaceous.
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Author’s contribution
Irfan Ullah (MS Scholar): conceptualization, methodology, field investigation, data curation, and draft writing Aamir Khan (PhD Scholar): contributed to data curation, conceptualization, reviewing, editing, and writing the original draft. Muhammad Tahir Shah (PhD, Professor) contributed to conceptualization, complilation, reviewing and editing. Liaqat Ali (PhD, Professor): supervision, data curation, reviewing and editing and funding acquisition. Asad Khan (PhD, lecturer) contributed to laboratory work, and data support.
All authors have read and agreed to the published version of the manuscript.