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Article

Characteristics and Deep Mineralization Prediction of the Langmuri Copper–Nickel Sulfide Deposit in the Eastern Kunlun Orogenic Belt, China

by
Cai Ma
1,
Baochun Li
2,3,4,*,
Jie Li
1,
Peng Wang
1,
Ji’en Dong
1,2,*,
Zhaoyu Cui
5 and
Shunlong Yang
5
1
Qinghai Geological Survey, MNR Technology Innovation Center for Exploration and Exploitation of Strategic Mineral Resources in Plateau Desert Region, Xining 810000, China
2
School of Geophysics and Information Technology, China University of Geosciences, Beijing 100083, China
3
School of Resources and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
4
Inner Mongolia Engineering Research Center of Geological Technology and Geotechnical Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
5
No.3 Exploration Institute of Geology Resources of Qinghai Province, Xining 810012, China
*
Authors to whom correspondence should be addressed.
Minerals 2024, 14(8), 786; https://doi.org/10.3390/min14080786
Submission received: 11 June 2024 / Revised: 23 July 2024 / Accepted: 29 July 2024 / Published: 31 July 2024
(This article belongs to the Special Issue Geoelectricity and Electrical Methods in Mineral Exploration)
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Abstract

:
The discovery of a Cu-Ni sulfide deposit in Langmuri of the Eastern Kunlun Orogenic Belt holds significant geological implications. This study, based on the examination of the metallogenic geological body, metallogenic structure, and metallogenic process characteristics, suggests that the deposit is a magmatic Cu-Ni sulfide deposit formed in the collision of orogenic and post-extension processes of the Late Ordovician. The early mineralization of the deposit was primarily derived from the differentiation of sulfides in the mafic–ultramafic rock (450–439 Ma) of the Late Ordovician, while the late-stage mineralization underwent significant superimposed modification by the magmatic–hydrothermal activity of crustal-contaminated biotite granite (415 Ma). In addition, this article analyzes the measurements of the geochemical studies of sediments, and the magnetic and gravity measurements carried out in the area, focusing on the geochemical and geophysical anomaly characteristics in the study area, and selects favorable exploration areas, which have been confirmed to have multiple mineral bodies. By integrating comprehensive gravity, magnetic, induced polarization, and audio-frequency magnetotelluric profile measurements, this study analyzes delineated mineralized zones and the deep extensions of surface mineral bodies to assess deep mineralization potential and identify deep ore-finding targets. It suggests that diverse and scattered mafic–ultramafic complexes in the Langmuri mining area have a large-scale distribution of ore-bearing rocks in the deep. Through the analysis and inverse of the geophysical data, a deep mineralization predictive model was established in the basic–ultrabasic rock mass. The study presents prospects for the delineation of the deep-seated mineralization in the Langmuri deposit.

1. Introduction

The Eastern Kunlun Orogenic Belt constitutes a significant component of the Qinling–Qilian–Kunlun metallogenic domain, exhibiting favorable conditions for the formation of magmatic Cu-Ni-Co sulfide deposits and prospecting potential. In recent years, the discovery of large-scale Ni-Co deposits in Xiarihamu in the western metallogenic belt, large-scale Cu-Ni deposits in the Shitoukengde area in the middle metallogenic belt, and small-scale Cu-Ni deposits in Langmuri in the eastern metallogenic belt have been reported [1,2,3]. Additionally, multiple Cu-Ni mineralized spots, such as Binggounan and Xiwanggou, have been identified [4,5,6]. These mineralized spots are associated with magmatic activities during the evolution of the Proto-Tethys Ocean [7,8,9,10,11,12]. Studying deposits belonging to the same genetic type is important for prospecting the Cu-Ni deposits in the Eastern Kunlun Orogenic Belt.
Since the discovery of the Langmuri Cu-Ni sulfide deposit, scholars have studied it by geological characteristics, mechanisms, prospecting indicators, ore-forming ages, ore-forming regularities, and metallogenic prediction [4,13,14]. Despite metallogenic prediction being focused on magnetic anomalies [15], comprehensive research on metallogenic prediction remains limited. It constrains the deep-seated mineralization of the deposit. This paper has used gravity, magnetic, induced polarization (IP), and audio magnetotelluric (AMT) methods and measurements of 1:25,000-scale geochemical studies in Langmuri. Considering the ore-forming background and regularities, this study utilizes the theory of mantle-branch structure-associated metallogenesis [16], collisional orogens [17,18], and the ore metallogenic prediction (including ore-forming geological bodies, ore-forming structures, and shear zones, and ore-forming characteristics) to establish a geological–geophysical prospecting model for the Langmuri mining area. Deep ore-finding targets are identified, indicating the potential for metallogenic prediction.

2. Geological Setting

The East Kunlun Orogenic Belt is situated at the junction of the Paleo-Asian tectonic domain and the Tethyan tectonic domain. Its northern boundary is adjacent to the Qaidam Block along the Northern Kunlun Fault, while its southern boundary adjoins the Songpan–Ganzi Block along the Animaqing Fault. To the east, it is demarcated by the Wenquan Fault, and to the west, it is separated from the Tarim Block by the Altyn Fault (Figure 1a).
According to the Northern Kunlun Fault, Central Kunlun Fault, and Animaqing Fault, the East Kunlun Orogenic Belt was divided into three structural belts: the Northern Kunlun, Central Kunlun, and Southern Kunlun Orogenic belts [19,20]. The Central Kunlun Orogenic Belt, situated between the Central Kunlun Fault and the Northern Kunlun Fault, constitutes a composite magmatic arc formed during the Caledonian Hualixi orogenesis. Some Cu-Ni deposits associated with Silurian–Devonian mafic–ultramafic rocks, such as Xiarihamu, Shitoukengde, and Langmuri, indicate favorable conditions for the formation of magmatic Cu-Ni-Co sulfide deposits and metallogenic prediction within this magmatic arc [7,9,10,21,22]. The intrusion of Paleozoic mafic–ultramafic rock along the belt has led to the formation of Cu-Ni mineralization points [20,23]. The Southern Kunlun Orogenic Belt is a complex accretionary terrane with diverse ore-bearing formations and frequent tectonic–magmatic activities. It has recorded the evolution that opened to the closure of the Proto-Tethys Ocean, the subduction and consumption of the Paleo-Tethys Ocean starting from the Neoproterozoic [24,25,26].
The Langmuri mining area is situated in the eastern part of the composite magmatic arc of the Central Kunlun Orogenic Belt. The exposed stratigraphy in the deposit primarily comprises the basement metamorphic rocks of the Paleoproterozoic Jinshuikou Group, including gneisses, amphibolites, marble, leptynite, and biotite quartz schist. Influenced by tectonic and magmatic activities, they exhibit blocky or intrusive bodies [19,20] (Figure 1b).
The Langmuri mining area exhibits prominent faults, with 17 faults (F1–F17), predominantly characterized by nearly east–west trending, followed by northwest and northeast-trending faults. These structures provide favorable tectonic conditions for the intrusion and mineralization processes of Early Caledonian basic-ultramafic rocks and medium-acidic granites.
On the northern margin of the mining area, extensive Caledonian to Indosinian medium-acidic magmatic rocks (such as granodiorites, quartz diorites, monzogranites, biotite granites, and granites) are observed. Mafic–ultramafic rocks (including gabbro, norite, pyroxenite, and peridotite) in 17 locations are distributed in the central-southern area, constituting the principal ore-bearing bodies. The ore-bearing bodies are associated with gabbro, pyroxene, limburgite, websterite, and pyroxenite. Pyroxene and websterite are the main ore-bearing bodies.
In the Langmuri mining area, 36 Ni and 9 Pt-Pd ore bodies have been delineated. The ore bodies are mainly veins, lenses, and tabular bodies [15]. The ore bodies are generally 160–300 m in length, with a thickness ranging from 1.75 to 15.9 m, and with grades of Ni ranging from 0.23 wt % to 1.72 wt %, Co from 0.016 wt % to 0.11 wt %, and Cu from 0.19 wt % to 0.55 wt %. The Pt-Pd ore bodies have a thickness of 1.98-5.94 m, with grades of Pt+Pd ranging from 0.34 g/t to 1.58 g/t.
The ore types primarily comprise Ni sulfide ores. The ore minerals mainly consist of pyrrhotite, pentlandite, chalcopyrite, pyrite, magnetite, etc. Secondary minerals include annaberg, malachite, and limonite. Vein minerals mainly comprise olivine, pyroxene, plagioclase, biotite, amphibole, talc, serpentine, phlogopite, quartz, and carbonate minerals. Among these, olivine, pyroxene, and plagioclase are primary silicate minerals, while the other minerals are the alteration products of primary silicate minerals (Figure 2).
The ore structures primarily consist of disseminated, veinlet, and massive structures. Ore textures include idiomorphic to hypidiomorphic–idiomorphic granular, xenomorphic granular, inequigranular, replacement, inclusion, and sponge meteorite textures. The associated fabric characteristics and spatial distribution of ore conform to the characteristics of magmatic deposits, exhibiting zonal distribution from bottom to top, characterized by massive, dense disseminated, and disseminated zones.

3. Methods

In the Langmuri mining area, geochemical, magnetic, gravity, IP, and AMT methods were employed to delineate prospective ore-finding targets. The geochemical 1:25,000 studies of sedimentary rocks were also fulfilled. This method is an exploration geochemical method for arid and semi-arid high-altitude mountain areas such as the Eastern Kunlun metallogenic belt in Qinghai Province. It mainly focuses on favorable mineralization areas, using a sampling density of greater than or equal to 20 points/km2 rule to conduct large-scale stream sediment measurement. Crush the sample to −0.074mm, test it using methods for analyzing the national first-grade standard material GBW series (soil or water sediment), and finally analyze the elemental composition and content. Using inductively coupled plasma mass spectrometry (ICP-MS) to measure copper and nickel; the sample is decomposed with hydrofluoric acid, nitric acid, and perchloric acid, followed by a complete removal of perchloric acid. After dissolving in aqua regia, the solution is made up to a certain volume and mixed well. A portion of the clear solution is then diluted with nitric acid (3 + 97) and analyzed on an X Series 2 plasma mass spectrometer. It identifies the geochemical characteristics of major ore-forming elements and associated elements; delineates, and evaluates geochemical anomalies; selects ore-prospecting target areas; and provides the geochemical basis for geological prospecting. A series of important results [27,28,29] have been achieved using this geochemical measurement method.
The IP method measures electrical potentials from subsurface charges. If a constant current is injected into the ground and shut down, the voltage measured between two electrodes decays more or less slowly over time [30]. The polarization rates are defined as Vt/V0, where V0 is the initial voltage before the current is shut off and Vt is the measured voltage at some later time. The IP has been developed to locate mineral deposits like massive or pervasive ore bodies [31]. We used 5kW-10kW transmitters to emit 2A current and WDJS-2 receivers to receive signals.
The measurements of the gravity and magnetic fields on a surface describing the measurement positions from varying terrain with constant or variable density/magnetization is a classical approach in geophysics [32]. A combination of geological information with gravitational and magnetic data inversion information was used to determine the space–time genesis of the metallogenic objects in potential mineral targets (intrusions, ore-forming strata, and ore mineralization-favorable faults) [33].
The AMT method is an important exploration method for studying deep underground structures. It has the characteristics of large detection depth, low exploration cost, and sensitivity to low resistivity anomalies. It collects signals from natural electromagnetic fields and calculates the apparent resistivity [34]. It is widely used in mineral exploration and is commonly used in the search for metallic resources such as copper, molybdenum, lead-zinc, bauxite, and uranium [35]. This article used the MTU5-A to collect a time series of natural electromagnetic fields, eliminating irrelevant interference through remote reference magnetotelluric. We obtained a two-dimensional electrical structure model through a nonlinear conjugate gradients algorithm.

4. Result

4.1. Geochemistry

The information regarding the main ore-forming elements of Ni, Co, and Cu was extracted from the anomalies observed in the 1:25,000 geochemical studies of sedimentary rocks. A total of 13 anomalies of Ni, Co, and Cu were identified in the Langmuri mining area (Figure 1b). Drainage anomalies HS71 and HS73 are identified as the primary induced mineralization anomalies, corresponding to lithological units ②, ③, and ④.
The HS71 anomaly exhibits a northwest-trending belt distribution, covering an area of 0.51 km². Within the HS71 anomaly, mineralized limburgite was discovered, delineating 16 ore bodies. The Ni and Co elements exhibit internal, intermediate, and external zoning, with Ni peaking at 495 ppm and Co peaking at 81 ppm. Cu shows a singular point anomaly with a peak value of 95 ppm.
The HS73 anomaly presents an irregular east–west distribution, covering an area of 0.6 km². Within the HS73 anomaly, mineralized limburgite was discovered, delineating 18 Ni ore bodies. The main ore-forming elements are well correlated, with a distinct concentration center and a large anomaly scale, displaying internal, intermediate, and external zoning. The Ni peak value is 1647 ppm, the Cu peak value is 724 ppm, and the Co peak value is 157 ppm.

4.2. Gravity and Magnetic Methods

Through high-precision magnetic surveying at 1:10,000, 17 magnetic anomalies (C1–C17) were delineated. Among these anomalies, C2, C3, C4, C7, C14, and C15 are identified as mineralization anomalies, exhibiting anomaly values ranging from −830 nT to +1206 nT (Figure 3a). The anomalies are categorized into the northern, central, and southern regions. Considering the geological conditions of the mining area, mafic–ultramafic rocks are found within the magnetic anomalies. According to the magnetic properties measurement results of the specimen, the gabbro has strong magnetism, with a high magnetization susceptibility of up to 0.22 SI. Magnetized gabbro, diorite, and diabase are highly magnetic, with a magnetization susceptibility of 0.06 SI, which is the main cause of the strong magnetic anomaly in the area; other rocks like the black biotite diorite have a magnetization susceptibility equal to or less than about 0.01 SI, falling into the category of medium to weak magnetism. The C2 magnetic anomaly is located within the HS71, and the C4 magnetic anomaly is located within the HS73.
A 1:10,000 gravity survey was conducted to investigate the deep conditions of the C2 to C8 magnetic anomaly zone in the Langmuri mining area. The Bouguer gravity anomalies exhibit a characteristic of low in the northeast and high in the southwest. The isogradient lines of the Bouguer gravity anomaly extend northwestward. In contrast, the southwestern area exhibits a high Bouguer gravity anomaly. The amplitude of the high Bouguer gravity anomaly gradually increases from northwest to southeast. A gravity gradient zone in the central part is identified (Figure 3b). The low Bouguer gravity anomaly on the northern side is associated with widespread intrusive medium-acidic rocks in the basement of the Paleoproterozoic Jinshuikou Group. The Bouguer gravity gradient zone in the central part is related to northwest trending structures and minor intrusive high-density mafic–ultramafic rocks in the basement of the Paleoproterozoic Jinshuikou Group. The high Bouguer gravity anomaly zone on the southern side corresponds to the magnetic anomaly C6, which is associated with thick and high-density mafic–ultramafic rocks intruded in the basement of the Paleoproterozoic Jinshiukou Group.

4.3. Induced Polarization and Audio Magnetotelluric Methods

AMT and IP profiles (5.5 km) were deployed in the magnetic and Bouguer gravity anomaly areas (Figure 1b). Before profile deployment, the physical properties of the rock and ore samples were determined. Gneisses, granodiorites, monzogranites, and pyroxenite exhibit high resistivity (ρ > 1500 Ω·m), whereas biotite granites, limburgite, and mineralized limburgite display lower resistivity (ρ < 1000 Ω·m). Biotite granites, gabbro, and mineralized limburgite exhibit high polarization rates (η: 2.8%–4.2%), while the polarization rates for other lithologies are less than 1.5%.
According to the IP anomaly curves, it is evident that both the northern and southern regions exhibit characteristics of low resistivity and high polarization rates. The southern anomaly is 1500 m wide, with average polarization rates of 5%–12% and resistivity of less than 400 Ω·m. The northern anomaly is more than 1500 m wide, displaying average polarization rates of 6%–10% and resistivity of less than 400 Ω·m. Combining the characteristics of resistivity and polarization rates with the rock outcrops, it is inferred that mineralized mafic–ultramafic rocks or mineralized bodies cause the “low resistivity, high polarization rates” anomalies.
In total, AMT data were collected at 107 stations. The frequency of AMT data is 10−4–1 s (Figure 4). The data quality is good, with significant errors only when the frequency is less than 1Hz. Before inversion, dimensional analysis is necessary by analyzing the phase tensors [36]. The shallow depths (period < 0.01 s) structure consists of damaged rocks and unconsolidated sediments in the Langmuri mining area are predominantly 1-D or 2-D structures, as evidenced by the near-circular phase tensors and relatively small tippers (Figure 5a–c). At periods 0.1–1 s, the phase tensor becomes elliptical (skew > 6° or <−6°) which highlights 3-D (Figure 5d–e) structures.
The 2-D inversion model of the AMT method is illustrated in Figure 6c. A large area of high-resistivity anomalies (>500 Ω·m) is observed in the central part of the profile. Considering the geological characteristics of the Langmuri mining area, the high-resistivity anomaly (R1) in the middle section of the profile is predominantly composed of gneiss from the Paleoproterozoic Jinshuikou Group, intruded by a small amount of gabbro. On the southern side of the profile, two steeply dipping low-resistivity anomalies (C1, C2) are identified. Based on the geological features revealed by C14ZK01, it is inferred that the ore-bearing mafic–ultramafic rocks intruded along the structures F9 and F12 contribute to the low-resistivity anomalies (<100 Ω·m). On the northern side of the profile, a south-dipping low-resistivity anomaly is observed. Combined with the drilling results, it is deduced that the low-resistivity anomalies are caused by the intrusion of ore-bearing mafic–ultramafic rocks along the nappe structure.
Based on the geological characteristics of the deposit, no carbonaceous rocks are affecting geophysical interpretations. The gravity, magnetic, and resistivity anomalies in the northern mining area are attributed to mineralization. Drillings have identified multiple ore-bearing rock and ore bodies within a depth of 500 m. Beneath the ore bodies, the resistivity is lower, and the low-resistivity anomalies are remarkable, exhibiting a trend in extension towards the south. This suggests that the ore-bearing pyroxenite and ore bodies are the upper ore veins of deeper-seated, larger-scale ore-bearing rock and ore bodies. Deeper than 800 m, there may exist extensive ore-bearing pyroxenite or ore bodies, thus delineating the deep ore-finding target BQ-1 (Figure 6d). However, due to the higher electrical resistivity of BQ-1, it may be different from other sulfide ore bodies.
In the southern mining area, the intersection of the east–west fault (such as F9) with the north-eastward fault (such as F12) coincides with magnetic, resistivity, and geochemical anomalies. Several large-area Co and Ni anomalies distributed on the surface reflect favorable mineralization conditions. The correspondence between the high-magnetic, low-resistivity, and high-polarization anomalies of C14 is evident. The ore-bearing mafic–ultramafic veins and ore bodies below 160 m in C14ZK01 reveal a mineralized anomaly, indicating promising prospects for deep-seated mineralization. Additionally, there are south-dipping low-resistivity anomalies (800 m wide) around F9 and F13. These anomalies coincide with the lowest resistivity in the AMT profile and are verified by C14ZK01, suggesting that they are caused by the nappe structure during the collisional orogeny and the intrusion of ore-bearing mafic–ultramafic rocks along them. North-dipping low-resistivity anomalies (500 m wide) are observed around F11 and F12. These anomalies are attributed to the nappe structure during the collisional orogeny and the intrusion of ore-bearing mafic–ultramafic rocks along them. Therefore, the area below 800 m is delineated as the deep ore-finding target BQ-2.
In the central part of the mining area, medium- to high-resistivity anomalies also exhibit gravity and magnetic anomalies. The electrical structure demonstrates characteristics of high to medium resistivity in the upper section and low resistivity in the lower section. Combining the outcrops of the Paleoproterozoic Jinshuikou Group gneiss and diorite, along with the C6 magnetic anomalies and G19 high gravity anomalies, it is inferred that the anomalies are caused by the intrusion of ore-bearing mafic–ultramafic rocks along steeply dipping fault within the basement rock mass. Deeper than 500 m, a large-scale ore-bearing diorite may exist, delineating it as the deep ore-finding target BQ-3.

5. Discussion

To summarize the prospecting, this study analyzed the spatial–temporal distribution patterns, geological characteristics, and metallogenic regularity of the Langmuri Cu-Ni sulfide deposits. The ore-bearing formation in the mining area is primarily associated with intrusive gabbro, pyroxene, limburgite, and pyroxenite in the Paleoproterozoic basement. Cu-Ni mineralization predominantly exists in the pyroxene-limburgite, with limburgite as the dominant lithology. Ultramafic rocks rich in peridot and orthopyroxene are the most important ore-bearing lithologies [38]. In the mineralized rocks of the Langmuri mining area, peridot is the main peridotite (Fo = 81–88), and pyroxene is mostly bronzite (En = 78–86) [13]. The coexistence of olivine and orthopyroxene in the mafic–ultramafic rocks associated with Cu-Ni sulfide deposits, with similar Fo and En values, is favorable for mineralization [39]. LA-ICP-MS U-Pb dating are 438.8 ± 2.6 Ma and 439.5 ± 2.0 Ma for the pyroxene and gabbro, respectively [13,19], confirming the mineralization age in the region to be in the Silurian. The widespread peridotite and pyroxenite indicate significant mantle melting, resulting in primary magmas enriched in high Mg, S, and metallic elements. Electron probe X-ray microanalysis from the mafic–ultramafic rock mass suggests that the golden mica formed through the evolution of mantle-derived magmas, indicating mantle metasomatism. The golden mica is a product of fluid metasomatism after the release of fluids from the oceanic crust [20]. These studies demonstrate that the mafic–ultramafic rocks are products of mantle–crust hybrid magmas enriched in ore-forming materials.
The east–west trending faults (F9, F11, F13, etc.) and northeast trending faults (F7, F8, F12, etc.) are the principal ore-controlling structures. These faults, formed during the Caledonian subduction–collision orogenic processes, have influenced the emplacement and mineralization of mafic–ultramafic rocks, as well as the subsequent intermediate-acidic magmatic activity and hydrothermal superimposed mineralization. Additionally, the belt between the basement and intrusive rocks, the belt between mineralized rocks/bodies and later intermediate-acidic intrusive rocks, along with their secondary faults, exhibit evident control on veinlet-disseminated Q-Po-Ccp mineralization and platinum group element (PGE) mineralization [14]. These structures constitute the ore-controlling structures and ore structures of the deposit.
The ore-bearing rocks in the Langmuri mining area exhibit low silica, low titanium, and high magnesium. Specifically, the m/f ranges from 4.35 to 5.28 for pyroxenite, 1.03 to 3.06 for gabbro, and 2.60 to 5.28 for ore-bearing peridotite [13,14]. The m/f is within the range of 2 to 6.5, indicating basic–ultrabasic rocks, which are conducive to the formation of copper and nickel mineralization. The mining area exhibits enrichment in light rare earth elements and large-ion lithophile elements (Rb, Cs, U, Th, Ba, and K), depleted heavy rare earth elements, and high-field-strength elements (Nb, Ta, Zr, Hf, and Ti). The rare earth element contents are 86.6 to 152 ppm for gabbro and 8.11 to 8.85 ppm for pyroxene [13,14]. Both types of rare earth element distribution curves are nearly parallel and generally exhibit right-skewed patterns, resembling the distribution patterns of magmas derived from the partial melting of the depleted mantle. Specifically, the (La/Yb)N for gabbro ranges from 5.64 to 15.32, and for pyroxene ranges from 9.49 to 11.42, indicating strong fractionation between light and heavy rare earth elements, which reflects the magma differentiation of source magma within the ore-forming magmatic bodies.
The 87Sr/86Sr ratios of the ore-bearing pyroxene exhibits 0.77914 [40], higher than the mantle value of 0.702, with εNd(t) = 2.66, indicating that the primary magma originated from a depleted mantle and experienced crustal contamination. These geochemical characteristics reflect an island arc magmatism associated with subduction. Additionally, the S/Se ratio in the Langmuri samples ranges from 4181 to 9553 [19]. Considering the S/Se of the mantle (2850 to 4350) and crust (3500 to 10,000) [41], the sulfur source is from both the mantle and crust, indicating a crust–mantle interaction. The δ34S values of sulfur in the Langmuri Cu-Ni ores range from 3.72‰ to 6.95‰, higher than the mantle-derived δ34S values (0 ± 3‰) [19], suggesting sulfur is from the mantle. Crustal contamination leads to magma sulfur oversaturation during the ore-forming process of the magmatic Cu-Ni-Co deposits [5,42]. Furthermore, in the Langmuri mining area, the medium-acidic magmatic-hydrothermal fluid is related to biotite granite (415 Ma), indicating that in addition to the Silurian magmatic Cu-Ni-Co mineralization, early Devonian hydrothermal vein copper and platinum-group elements (PGE) mineralization have occurred [5,42].
The Langmuri Cu-Ni sulfide deposit primarily occurs within pyroxene or at the contact zones with gneisses, presenting as lens-like or parallel stratiform. The ore predominantly exhibits disseminated textures, with minor massive textures and sponge meteorite textures. The metallic mineralization is characterized by pentlandite, chalcopyrite (produced from PGE minerals), and pyrrhotite. These are typical magmatic sulfide deposits [4,15,20]. In the Eastern Kunlun Orogenic Belt, from late Caledonian to early Hercynian, the intrusion of mafic–ultramafic rocks and Cu-Ni mineralization event occurred. It is related to the detachment of subducted slab and mantle-derived magma upwelling [43]. Based on ore-forming environments, mineral assemblages, and mechanical genesis, the Cu-Ni sulfide deposit formed in collision-extensional settings in the late Caledonian to early Hercynian [17].
Based on the characteristics of the deposit, metallogenic type, and ore-forming mechanisms, a mineralization model for the Langmuri Cu-Ni sulfide deposit is proposed (Figure 7). The formation of the Langmuri Cu-Ni sulfide deposit is associated with the expansion–closure of the Proto-Tethys Ocean, which is related to the tectonic evolution and magmatic mineralization within the Proto-Tethys Ocean [5,7,10,11,44]. The collision mineralization process is delineated into three stages.
(1)
The subduction–collision orogenic processes (initial mineralization stage) (Figure 7a). In the Cambrian–Ordovician, the extensive expansion of the Proto-Tethys Ocean occurred along the southern margin of the Qaidam block. The subduction of the oceanic crust to the north underwent melting, decompression, and differentiation, triggering intermediate-acidic magmatic activities in island arcs [45]. The subducted oceanic crust underwent melting, thinning, and detachment, resulting in the formation of slab windows, facilitating the ascent of mantle-derived magmas rich in Cu, Ni, and other elements from the deep asthenospheric mantle, which amalgamated with the lower crust at the mantle wedge to form mafic–ultramafic magmatic melts (or magma chambers) [46,47].
(2)
The collision of orogenic and post-extension processes (the main mineralization stage) (Figure 7b). In the Silurian, the Proto-Tethys Ocean closed, resulting in the collisional orogeny of the oceanic crust with the Qaidam block, leading to crustal compression and thickening [7,10]. The late-stage dynamics of the collision were extensional mechanisms primarily. Ore-bearing mantle-derived magnesium mafic–ultramafic magmatic melts formed at the crust–mantle boundary rose along extensional structures driven by mantle thermal dynamics and underplating the lower crust. After decompression melting, the melts underwent crust–mantle mingling with crustal material, leading to sulfide saturation. During this process, temperature and pressure decreased, resulting in the crystallization and differentiation of oxide in the magma into silicate minerals. Elements such as Cu, Ni, Co, Pt, and Pd were fractionated and mineralized as sulfides, forming a four-layer structure of silicic magma, sulfide-bearing magma (disseminate textures), sulfide-rich magma (sponge meteorite textures), and sulfide melt (massive textures) from top to bottom [48]. In the late stages of magma differentiation, with increasing fractionation, decreasing temperature and pressure, and the involvement of volatile components such as water, abundant hydrothermal fluids formed in the post-magmatic stage. These hydrothermal fluids underwent metasomatism, resulting in alterations such as carbonation, serpentinization, and PGE mineralization, ultimately forming symbiosis-associated PGE minerals [49].
(3)
Superimposed mineralization processes (Figure 7c). During the Devonian, the continental crust thickened, and under the deep-seated crust–mantle differentiation, the intrusion of deep-seated medium-acidic magmatic rocks occurred in Hercynian [49]. The ore bodies were destructed by the orogenic event and underwent magmatic–hydrothermal alteration. The subsequent orogenic activities led to regional uplift. Despite undergoing late-stage structural displacement, oxidation, and erosion, the Cu-Ni deposits remained largely intact, ultimately forming the Langmuri Cu-Ni sulfide deposit.

6. Conclusions

In this study, we used geochemical, gravity, magnetic, IP, and AMT methods in the Langmuri mining area to delineate Bouguer gravity, magnetic, high polarization, low resistivity, and geochemical anomalies. Subsequently, based on the geological structure of the Langmuri Cu-Ni sulfide deposit and the spatial distribution of ore-bearing rock, guided by the theory of collisional orogens and mantle-branch structure-associated metallogenesis, a geological–geophysical prospecting model was constructed for the Langmuri mining area. Deep ore-finding targets were delineated which are BQ-1, BQ-2, BQ-3, and BQ-4.
The diverse and scattered ore bodies in the Langmuri Cu-Ni sulfide deposit are consistent with the theory of mantle-branch structure-associated metallogenesis. The lithological zonation in the mining area is consistent with the mafic–ultramafic rock of the Alaskan-type complexes [50]. The characteristics of ore bodies and the quality control of ore are consistent with the four-layer structure model, which are silicic magma, sulfide-bearing magma, sulfide-rich magma, and sulfide melt. It is typical of Cu-Ni sulfide deposits.
The Langmuri Cu-Ni sulfide deposit has undergone processes of subduction orogenic, collision of orogenic and post-extension, and superimposed reformation–mineralization. Following the formation of the deposit, it experienced orogenic activities. Apart from late-stage structural displacements and magmatic–hydrothermal alterations, prolonged erosion has exposed ore-bearing rock at the surface. However, concealed Cu-Ni ore bodies are generally well preserved. Consequently, the Langmuri mining area exhibits favorable metallogenic conditions and prospecting potential.

Author Contributions

C.M.: conceptualization, resources, writing—review and editing, funding acquisition, project administration, and investigation. B.L.: conceptualization, methodology, data curation, and writing—original draft. J.L.: supervision, resources, and writing—review and editing. P.W.: writing—review and editing. J.D.: writing—review and editing and investigation. Z.C.: writing—review and editing. S.Y.: writing—review and editing. All authors have read and agreed to the published version of the manuscript.

Funding

This work is supported by Qinghai Provincial Association for Science and Technology Youth Science and Technology Talent Support Project (2023QHSKXRCTJ47), Demonstration of Deep Exploration Breakthrough in Important Mineral Concentration Areas of Qinghai Province (2023085029ky004), Science and Technology Project of Inner Mongolia (2023QN04007) and National Key R&D Program of China (2022YFF0800702).

Data Availability Statement

Data will be made available upon request due to internal policy.

Acknowledgments

We would like to thank the MTPy code for plotting the resistivity curve and phase tensor [37].

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Liu, Y.; Li, W.; Jia, Q.; Zhang, Z.; Wang, Z.; Zhang, Z.; Zhang, J.; Qian, B. The Dynamic Sulfide Saturation Process and a Possible Slab Break-off Model for the Giant Xiarihamu Magmatic Nickel Ore Deposit in the East Kunlun Orogenic Belt, Northern Qinghai-Tibet Plateau, China. Econ. Geol. 2018, 113, 1383–1417. [Google Scholar] [CrossRef]
  2. Zhang, Z.-W.; Wang, Y.-L.; Wang, C.-Y.; Qian, B.; Li, W.-Y.; Zhang, J.-W.; You, M.-X. Mafic-ultramafic magma activity and copper-nickel sulfide metallogeny during Paleozoic in the Eastern Kunlun Orogenic Belt, Qinghai Province, China. China Geol. 2019, 2, 467–477. [Google Scholar] [CrossRef]
  3. Li, W.; Gao, Y.; Bagas, L. Ore forming process of magmatic Nickel-Copper-Cobalt sulfide deposits in China. Fundam. Res. 2024, in press. [CrossRef]
  4. Zhang, Y.; Pan, T.; Zhang, A.; He, S.; Qian, Y.; Bai, Y. Spatial Relationship between Eclogite and Copper-Nickel Mineralization in East Kunlun, China. Minerals 2023, 13, 330. [Google Scholar] [CrossRef]
  5. Li, W.; Zhang, Z.; Gao, Y.; Hong, J.; Chen, B.; Zhang, Z. Tectonic transformation of the Kunlun Paleo-Tethyan orogenic belt and related mineralization of critical mineral resources of nickel, cobalt, manganese and lithium. Geol. China 2022, 49, 1385–1407. [Google Scholar] [CrossRef]
  6. Liu, Y.; Zhang, J.; Feng, Z.; Yang, S.; Wang, Y.; Li, J.; Zhao, Z.; Wang, Z.; Li, S.; Chen, Z.; et al. Exploration and research progress of magmatic copper-nickel-cobalt sulfide deposits in the north-eastern margin of the Qinghai-Tibetan Plateau. Geol. China 2024. [Google Scholar] [CrossRef]
  7. Zhang, D.; Zhang, H.; Feng, C.; She, H.; Li, J.; Li, D. Fluid inclusions in orogenic gold deposits in the northern Qaidam margin-East Kunlun region. Geol. China 2007, 34, 843–854. [Google Scholar] [CrossRef]
  8. Pan, Y.; Zhou, W.; Xu, R.; Wang, D.; Zhang, Y.; Xie, Y.; Chen, T.; Luo, H. Geological characteristics and evolution of the Kunlun Mountains region during the early Paleozoic. Sci. China 1996, 39, 337–347. [Google Scholar]
  9. Chen, G.; Pei, X.; Li, R.; Li, Z.; Chen, Y.; Liu, C.; Pei, L. Multiple Sources of Indosinian Granites and Constraints on the Tectonic Evolution of the Paleo-Tethys Ocean in East Kunlun Orogen. Minerals 2022, 12, 1604. [Google Scholar] [CrossRef]
  10. Zhang, X.; Zhao, X.; Fu, L.; Li, Y.; Kamradt, A.; Santosh, M.; Xu, C.; Huang, X.; Borg, G.; Wei, J. Crustal architecture and metallogeny associated with the Paleo-Tethys evolution in the Eastern Kunlun Orogenic Belt, Northern Tibetan Plateau. Geosci. Front. 2023, 14, 101654. [Google Scholar] [CrossRef]
  11. Wu, F.; Wan, B.; Zhao, L.; Xiao, W.; Zhu, R. Tethyan geodynamics. Acta Petrol. Sin. 2020, 36, 1627–1674. [Google Scholar]
  12. Zhu, R.; Zhao, P.; Zhao, L. Tectonic evolution and geodynamics of the Neo-Tethys Ocean. Sci. China Earth Sci. 2022, 65, 1–24. [Google Scholar] [CrossRef]
  13. Li, S.; Sun, F.; Wang, L.; Li, Y.; Liu, Z.; Su, S.; Wang, S. Fluid inclusion studies of porphyry copper mineralization in Kaerqueka polymetallic ore district, East Kunlun Mountains, Qinghai Province. Miner. Depos. 2008, 27, 399–402. [Google Scholar]
  14. Tong, H.; Long, L.; Wang, Y.; Zhu, X.; Li, S.; Gu, Z.; Ma, C.; Dai, Y.; Li, J.; Yu, X.; et al. Metallogenic Characteristics of Langmuri Copper Polymetallic Deposit in East Kunlun and Its Ore Prospecting Enlightenment. Earth Sci. 2023, 48, 4349–4369. [Google Scholar]
  15. Yang, S.; Duan, H.; Yang, Y.; Zhang, H.; Mao, S.; Xiong, S. Metallogenic characteristics of nickel-platinum-palladium deposit in Langmuri area, Qinghai. Miner. Explor. 2022, 13, 1276–1287. [Google Scholar]
  16. Pirajno, F.; Santosh, M. Mantle plumes, supercontinents, intracontinental rifting and mineral systems. Precambrian Res. 2015, 259, 243–261. [Google Scholar] [CrossRef]
  17. Chen, J.; Xu, J.; Wang, B.; Yang, Z.; Ren, J.; Yu, H.; Liu, H.; Feng, Y. Geochemical differences between subduction- and collision-related copper-bearing porphyries and implications for metallogenesis. Ore Geol. Rev. 2015, 70, 424–437. [Google Scholar] [CrossRef]
  18. Zheng, Y.; Chen, Y.; Dai, L.; Zhao, Z. Developing plate tectonics theory from oceanic subduction zones to collisional orogens. Sci. China Earth Sci. 2015, 58, 1045–1069. [Google Scholar] [CrossRef]
  19. Li, H.; Jiang, S.; Li, S.; Su, H.; Dong, J.; Li, Y.; Chen, X. Geological characteristics, ore genetic mechanism and exploration indicators of magmatic nickel. cobalt deposits in the East Kunlun Orogenic Belt. Acta Petrol. Sin. 2023, 39, 1041–1060. [Google Scholar] [CrossRef]
  20. Zhang, Z.; Qian, B.; Wang, Y.; Li, W.; Zhang, J.; You, M. Understanding of the Metallogenic Ore-Bearing Mechanism and Its Indication of Prospecting Direction in Xiarihamu Magmatic Ni-Co Sulfide Deposit, East Kunlun Orogenic Belt. Northwestern Geol. 2020, 53, 153–168. [Google Scholar] [CrossRef]
  21. Li, X.; Huang, X.; Luo, M.; Dong, G.; Mo, X. Petrogenesis and geodynamic implications of the Mid-Triassic lavas from East Kunlun, northern Tibetan Plateau. J. Asian Earth Sci. 2015, 105, 32–47. [Google Scholar] [CrossRef]
  22. Zhang, J.; Ma, C.; Li, J.; Pan, Y. A possible genetic relationship between orogenic gold mineralization and post-collisional magmatism in the eastern Kunlun Orogen, western China. Ore Geol. Rev. 2017, 81, 342–357. [Google Scholar] [CrossRef]
  23. Han, Y.; Liu, Y.; Li, W. Mineralogy of Nickel and Cobalt Minerals in Xiarihamu Nickel–Cobalt Deposit, East Kunlun Orogen, China. Front. Earth Sci. 2020, 8, 597469. [Google Scholar] [CrossRef]
  24. Pan, G.; Xiao, Q.; Zhang, K.; Yin, F.; Ren, F.; Peng, Z.; Wang, J. Recognition of the oceanic subduction-accretion zones from the orogenic belt in continents and its important scientific significance. Earth Sci. 2019, 44, 1544–1561. [Google Scholar]
  25. Wang, K.; Xiao, W.; Windley, B.F.; Mao, Q.; Ji, W.; Sang, M.; Huang, P.; Wang, P. The Dashui Subduction Complex in the Eastern Tianshan-Beishan Orogen (NW China): Long-Lasting Subduction-Accretion Terminated by Unique Mid-Triassic Strike-Slip Juxtaposition of Arcs in the Southern Altaids. Tectonics 2022, 41, e2021TC007190. [Google Scholar] [CrossRef]
  26. Pei, X.; Li, R.; Li, Z.; Liu, C.; Chen, Y.; Pei, L.; Liu, Z.; Chen, G.; Li, X.; Wang, M. Composition feature and formation process of Buqingshan composite accretionary mélange belt in southern margin of East Kunlun orogen. Earth Sci. 2018, 43, 4498–4520. [Google Scholar]
  27. Zhao, J.; Xu, G.; Yang, B.; Guo, H.; Li, D.; Ma, Z.; Wei, L.; Xiong, S. Technique and application result of 1: 25000 geochemical survey in East Kunlun, Qinghai Province. Northwestern Geol. 2018, 51, 209–217. [Google Scholar]
  28. Zhao, A.; Yang, M.; Chen, X.; Li, D.; Li, J.; Qi, C.; Wei, Y.; Ma, Z.; Li, Y. Geochemical characteristics and metallogenic significance of the Dulan area in the eastern section of the East Kunlun Mountains derived from large—scale micro channel system (soil) measurement. Geol. Explor. 2020, 56, 1158–1169. [Google Scholar] [CrossRef]
  29. Chen, X.; An, Z.; Zhang, W.; Xu, Y.; Ma, Y.; Shi, L.; Tao, Z. Geochemical characteristics and Cr metallogenic potential evaluation of the middle section of the northern margin of the Qaidam Basin. Geophys. Geochem. Explor. 2023, 47, 353–364. [Google Scholar]
  30. Leroy, P.; Revil, A. A mechanistic model for the spectral induced polarization of clay materials. J. Geophys. Res. Solid Earth 2009, 114. [Google Scholar] [CrossRef]
  31. Cross, B.; Kirkland, C.L. Petrological control on chargeability with implications for induced polarization surveys. J. Appl. Geophys. 2021, 188, 104308. [Google Scholar] [CrossRef]
  32. Wu, L.; Chen, L. Fast Computation of Terrain-Induced Gravitational and Magnetic Effects on Arbitrary Undulating Surfaces. Surv. Geophys. 2023, 44, 1175–1210. [Google Scholar] [CrossRef]
  33. Wang, G.; Zhu, Y.; Zhang, S.; Yan, C.; Song, Y.; Ma, Z.; Hong, D.; Chen, T. 3D geological modeling based on gravitational and magnetic data inversion in the Luanchuan ore region, Henan Province, China. J. Appl. Geophys. 2012, 80, 1–11. [Google Scholar] [CrossRef]
  34. Li, B.C.; Zhang, L.T.; Ye, G.F.; Jin, S.; Wei, W.B.; Xie, C.L.; Chen, X.R. Upper mantle thermal structure beneath the eastern margin of the Tibetan Plateau inferred from electrical structure model. Chin. J. Geophys. 2020, 63, 1043–1055. [Google Scholar]
  35. Guo, Z.; Xue, G.; Liu, J.; Wu, X. Electromagnetic methods for mineral exploration in China: A review. Ore Geol. Rev. 2020, 118, 103357. [Google Scholar] [CrossRef]
  36. Caldwell, T.G.; Bibby, H.M.; Brown, C. The magnetotelluric phase tensor. Geophys. J. Int. 2004, 158, 457–469. [Google Scholar] [CrossRef]
  37. Krieger, L.; Peacock, J.R. MTpy: A Python toolbox for magnetotellurics. Comput. Geosci. 2014, 72, 167–175. [Google Scholar] [CrossRef]
  38. Li, L.; Sun, F.; Li, B.; Li, S.; Chen, G.; Wang, W.; Yan, J.; Zhao, T.; Dong, J.; Zhang, D. Geochronology, Geochemistry and Sr-Nd-Pb-Hf Isotopes of No. I Complex from the Shitoukengde Ni–Cu Sulfide Deposit in the Eastern Kunlun Orogen, Western China: Implications for the Magmatic Source, Geodynamic Setting and Genesis. Acta Geol. Sin. Engl. Ed. 2018, 92, 106–126. [Google Scholar] [CrossRef]
  39. Yang, F.; Liu, G.; Zhang, H.; Yang, C.; Li, X.; Li, Q.; Li, N.; Zhang, Z. A review of geological characteristics and time–space distribution of cobalt deposits in the Central Asian Orogenic Belt, Xinjiang, Northwest China. Int. Geol. Rev. 2023, 65, 1388–1408. [Google Scholar] [CrossRef]
  40. McKenzie, D.; O’Nions, R.K. Mantle reservoirs and ocean island basalts. Nature 1983, 301, 229–231. [Google Scholar] [CrossRef]
  41. Hattori, K.H.; Arai, S.; Clarke, D.B. Selenium, tellurium, arsenic and antimony contents of primary mantle sulfides. Can. Miner. 2002, 40, 637–650. [Google Scholar] [CrossRef]
  42. Li, W.; Wang, Y.; Qian, B.; Liu, Y.; Han, Y. Discussion on the formation of magmatic Cu-Ni-Co sulfide deposits in margin of Tarim Block. Earth Sci. Front. 2020, 27, 276–293. [Google Scholar] [CrossRef]
  43. Zhang, J.; Lei, H.; Ma, C.; Li, J.; Pan, Y. Silurian-Devonian granites and associated intermediate-mafic rocks along the eastern Kunlun Orogen, western China: Evidence for a prolonged post-collisional lithospheric extension. Gondwana Res. 2021, 89, 131–146. [Google Scholar] [CrossRef]
  44. Li, W. The primary discussion on the relationship between Paleo-Asian Ocean and Paleo-Tethys Ocean. Acta Petrol. Sin. 2018, 34, 2201–2210. [Google Scholar]
  45. Torsvik, T.H.; van der Voo, R.; Doubrovine, P.V.; Burke, K.; Steinberger, B.; Ashwal, L.D.; Trønnes, R.G.; Webb, S.J.; Bull, A.L. Deep mantle structure as a reference frame for movements in and on the Earth. Proc. Natl. Acad. Sci. USA 2014, 111, 8735–8740. [Google Scholar] [CrossRef] [PubMed]
  46. Gao, J.; Klemd, R.; Zhu, M.; Wang, X.; Li, J.; Wan, B.; Xiao, W.; Zeng, Q.; Shen, P.; Sun, J.; et al. Large-scale porphyry-type mineralization in the Central Asian metallogenic domain: A review. J. Asian Earth Sci. 2018, 165, 7–36. [Google Scholar] [CrossRef]
  47. Richards, J.P.; Şengör, A.M.C. Did Paleo-Tethyan anoxia kill arc magma fertility for porphyry copper formation? Geology 2017, 45, 591–594. [Google Scholar] [CrossRef]
  48. Li, L.; Zhang, D.; Tan, S.; Sun, F.; Wang, C.; Zhao, T.; Li, S.; Yang, Y. The parental magma composition, crustal contamination process, and metallogenesis of the Shitoukengde Ni-Cu sulfide deposit in the Eastern Kunlun Orogenic Belt, NW China. Resour. Geol. 2021, 71, 339–362. [Google Scholar] [CrossRef]
  49. Jun, L.; Gui, X. Temporal-spatial distribution and geodymanic settings of magmatic Ni-Cu-(PGE)sulfide deposits in China. Acta Petrol. Sin. 2007, 23, 2561–2594. [Google Scholar]
  50. Shehta, E.A.; Shehata, A.; Mohamed, A.O. Geochemistry of an Alaskan-type mafic-ultramafic complex in Eastern Desert, Egypt: New insights and constraints on the Neoproterozoic island arc magmatism. Geosci. Front. 2019, 10, 941–955. [Google Scholar] [CrossRef]
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Figure 1. (a) Geologic map of the East Kunlun Orogenic Belt with the positions of the Cu-Ni-Co deposits (modified after Zhang, Pan, and Zhang et al. [4]). (b) The geological map of the Langmuri mining area.
Figure 1. (a) Geologic map of the East Kunlun Orogenic Belt with the positions of the Cu-Ni-Co deposits (modified after Zhang, Pan, and Zhang et al. [4]). (b) The geological map of the Langmuri mining area.
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Figure 2. Photomicrograph of ore from the Langmuri Cu-Ni deposit under a microscope. (a–c) plane polarized light; (d–f) cross polarized light; Po—pyrrhotite; Ccp—chalcopyrite; Pn—pentlandite; Mag—magnetite.
Figure 2. Photomicrograph of ore from the Langmuri Cu-Ni deposit under a microscope. (a–c) plane polarized light; (d–f) cross polarized light; Po—pyrrhotite; Ccp—chalcopyrite; Pn—pentlandite; Mag—magnetite.
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Figure 3. (a) Contour map of the magnetic anomalies at 1:10,000 for the Langmuri mining area; (b) the map of Bouguer gravity anomalies at 1:10,000.
Figure 3. (a) Contour map of the magnetic anomalies at 1:10,000 for the Langmuri mining area; (b) the map of Bouguer gravity anomalies at 1:10,000.
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Figure 4. Typical apparent resistivity–phase curves before data editing. Station locations are marked in Figure 5a. (a–f) show the apparent resistivity–phase curves of MT stations 1100, 2600, 3300, 4150, 5300, and 6250, respectively.
Figure 4. Typical apparent resistivity–phase curves before data editing. Station locations are marked in Figure 5a. (a–f) show the apparent resistivity–phase curves of MT stations 1100, 2600, 3300, 4150, 5300, and 6250, respectively.
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Figure 5. (a–e) Normalized phase tensor map along the AMT profile (using MTPy code [37]).
Figure 5. (a–e) Normalized phase tensor map along the AMT profile (using MTPy code [37]).
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Figure 6. A geological–geophysical comprehensive prospecting model for the Langmuri mining area (See Figure 1 and Figure 3 for the AMT/IP profile position in the geologic and anomaly maps.). (a) Bouguer gravity anomaly (Δg), magnetic anomaly (ΔT), polarization rates anomaly (η), and resistivity anomaly (ρ) curve. (b) Geological map along the AMT/IP profile. (c) A vertical profile of the 2-D resistivity inversion model of the AMT method. (d) A map of the promising prospects of ore-finding targets.
Figure 6. A geological–geophysical comprehensive prospecting model for the Langmuri mining area (See Figure 1 and Figure 3 for the AMT/IP profile position in the geologic and anomaly maps.). (a) Bouguer gravity anomaly (Δg), magnetic anomaly (ΔT), polarization rates anomaly (η), and resistivity anomaly (ρ) curve. (b) Geological map along the AMT/IP profile. (c) A vertical profile of the 2-D resistivity inversion model of the AMT method. (d) A map of the promising prospects of ore-finding targets.
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Figure 7. Metallogenic model of Langmuri Cu-Ni sulfide deposit. (a) The subduction–collision of orogenic processes. (b) The collision of orogenic and post-extension processes. (c) Superimposed mineralization processes.
Figure 7. Metallogenic model of Langmuri Cu-Ni sulfide deposit. (a) The subduction–collision of orogenic processes. (b) The collision of orogenic and post-extension processes. (c) Superimposed mineralization processes.
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Ma, C.; Li, B.; Li, J.; Wang, P.; Dong, J.; Cui, Z.; Yang, S. Characteristics and Deep Mineralization Prediction of the Langmuri Copper–Nickel Sulfide Deposit in the Eastern Kunlun Orogenic Belt, China. Minerals 2024, 14, 786. https://doi.org/10.3390/min14080786

AMA Style

Ma C, Li B, Li J, Wang P, Dong J, Cui Z, Yang S. Characteristics and Deep Mineralization Prediction of the Langmuri Copper–Nickel Sulfide Deposit in the Eastern Kunlun Orogenic Belt, China. Minerals. 2024; 14(8):786. https://doi.org/10.3390/min14080786

Chicago/Turabian Style

Ma, Cai, Baochun Li, Jie Li, Peng Wang, Ji’en Dong, Zhaoyu Cui, and Shunlong Yang. 2024. "Characteristics and Deep Mineralization Prediction of the Langmuri Copper–Nickel Sulfide Deposit in the Eastern Kunlun Orogenic Belt, China" Minerals 14, no. 8: 786. https://doi.org/10.3390/min14080786

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