Petrographical and Geochemical Characteristics of Magmatic Rocks in the Northwestern Siberian Traps Province, Kulyumber River Valley. Part II: Rocks of the Kulyumber Site

The origin of the Siberian trap province is under discussion even though numerous models of its formation have been created over the last three decades. This situation is mainly due to lack of modern geochemical data on magmatic rocks around the province. These data are a very important tool to reconstruct of magmatic evolution within the province in time and space and to understand a mechanism of province formation. Geochemical study has only been carried out so far for the Norilsk and Meimecha–Kotuy areas. For the first time, we have studied the geochemical and mineralogical characteristics of magmatic rocks at the Kulyumber river valley located 150 km to south from the Norilsk ore district, in the junction of the Tunguska syneclise and Norilsk–Igarka zone. It comprises three sites, i.e., Khalil, Kaya, and Kulyumber. The geochemical data on the magmatic rocks of the Khalil and Kaya sites were published earlier (Part I). This article (Part II) regards geochemical and mineralogical data on igneous rocks at the Kulyumber site. Seventeen intrusive bodies (41 samples) and six samples of sedimentary rocks were studied by X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). Isotopes analyses (Sr, Nd, Pb) were conducted for 12 samples. These data were compared with data for intrusions of the Norilsk area, the Dzhaltulsky massif, Kureyka river, and intrusions in Angara river valley published earlier. The whole list of analyses includes 102 items. Three groups of intrusive rocks were recognized: (1) Mafic rocks with elevated K2O without negative Ta-Nb and Pb-positive anomalies, with (Gd/Yb)n = 2.0 and εNd = −1.0; attributed to a new Kulyumbinsky complex; (2) subalkaline rocks with elevated SiO2,TiO2, P2O5, and K2O with small negative Ta-Nb and positive Pb anomalies and (Gd/Yb)n = 1.8, εNd = −3.8; Ergalakhsky complex; and (3) mafic rocks with strong Ta-Nb and Pb anomalies and (Gd/Yb)n = 1.2–1.4, εNd = +0.4–+2.2. The third group is rather nonhomogeneous and includes intrusions of the Norilsk, Kuryesky, Katangsky, Ogonersky, and Daldykansky complexes differing in MgO content and trace element distribution (values of Ta-Nb, Pb, and Sr anomalies). Three groups of intrusive bodies had different magma sources and different condition of crystallization reflecting their origin in rift and platform regimes.

The research of igneous rocks around the Siberian province is an ongoing project and the results will be published in a series of articles. The first area that was studied was the Kulyumber river valley (KRV) located 150 km to the south of the Norilsk area [50] (Figure 1). Its tectonic structures and magmatic rocks are very similar to that of the unique Norilsk ore district. The KRV is located between the Tunguska syneclise and Norilsk-Igarka paleorift tectonic zone and provide information on magmatic activities within both structures. Additionally, unlike poorly mineralized nearby areas, the KRV includes some disseminated and massive sulfide ore potentials. We studied igneous rocks at three sites within the Kulyumber river valley including two northern sites (Khalil and Kaya) and one southern site, Kulyumber site.
Minerals 2020, 10, x FOR PEER REVIEW 3 of 44 ratio, which evidences presence of garnet in magmas' sources. The upper formations consist of tholeiitic basalts with TiO2 < 1 wt.% and low Gd/Yb ratio. Intrusive bodies are mostly enclosed by sedimentary rocks, and are exposed in the western part of the area (Figure 1). During the geological mapping (1:200,000 scale) these rocks were classified into several complexes on the basis of their textures and structure as well as a few X-ray fluorescence (XRF) analyses. They were attributed to the intrusive complexes typical of the Tunguska syneclise (Katangsky, Kuzmovsky, [53]), the Norilsk area (Ergalakhsky, Norilsk, Daldykansky, Ogonersky) [52], and the local Kureysky complex. However, this classification does not take into account modern geochemical techniques that allow distinguishing different types of intrusive rocks more precisely.
The intrusions occur as sill-like bodies (with a thickness up to 5-6 to 100 m and a length of up to 10-15 km). Rare dykes cut volcanic rocks. The magma intrusion was mainly controlled by Imangdinsky-Letninsky and Khalilsky faults ( Figure 2). Intrusive bodies compositionally vary from olivine gabbro-dolerite to gabbro and leucogabbro. Magnesium-rich rocks (MgO = 9 wt.%) rather occur as separate horizons within differentiated intrusions than forming separate bodies.

Materials and Methods
The authors studied igneous rocks sampled from the outcrops in the Kulyumber river valley including three sites, i.e., the (1) Khalil, (2) Kaya, and (3) Kulyumber (samples labeled X, 3.21-3. 22, and Kul, respectively) (Figures 2 and 3 [51]) and from the cores of the boreholes PR-1, PR-4, and PR-11 drilled by Norilskgeology Ltd. and shown in Figure 4. The last area is located immediately to the west from the Kulyumber site. Its eastern boundary coincides with the This article briefly describes the geology of the KRV and petrological and geochemical characteristics of rocks (mostly, intrusive rocks) of the Kulyumber site, whereas, magmatic rocks in the northern part of this area were described earlier [51]. For the first time, the authors gathered a large amount of modern geochemical and mineralogical data on magmatic rocks of the Kulyumber river valley. That allowed us to subdivide intrusive rocks into complexes more correctly than was done before.

Brief Geological Characteristics of the Kulyumber River Valley
The study area is located in the Northwestern Siberian platform (Figure 1) where the Tunguska syneclise joins with the Norilsk-Igarka paleorift. The tectonic structure of the area is described in [51] on the basis of geophysical data (1:200,000 gravity mapping and aeromagnetic data of 1:100,000 scale). It is characterized by a submeridional band of the gravitational field positive values and low values of the magnetic field stretching along the Yenisey river (100 km wide) and bordering the ancient Siberian craton. It has three sublatitude branches, one of them coincides with the stretch of the Kulyumber river valley.
The local tectonic structures include the Nirungdinsky trough and the Mogen-Khalil anticline ( Figure 2). The Lower Ordovician-Lower Carboniferous formations in the area consist of carbonate-terrigenous rocks, whereas the Tunguska Group (C 2 -P 2 ) sediments are composed of sandstones and coal. The Late Permian-Early Triassic magmatic rocks belong to the Siberian flood basalts province. Like the Norilsk area [52], volcanic rocks from the Nirungdinsky trough are divided into several formations, including Syverminsky, Gudchikhinsky, Khakanchansky, Tuklonsky, and Nadezhdinsky, that were comprehensively described in the first part of the article [51]. The two lower formations contain trachybasalts and olivine basalts with TiO 2 content >1.5 wt.% and high Gd/Yb ratio, which evidences presence of garnet in magmas' sources. The upper formations consist of tholeiitic basalts with TiO 2 < 1 wt.% and low Gd/Yb ratio.
Intrusive bodies are mostly enclosed by sedimentary rocks, and are exposed in the western part of the area (Figure 1). During the geological mapping (1:200,000 scale) these rocks were classified into several complexes on the basis of their textures and structure as well as a few X-ray fluorescence (XRF) analyses. They were attributed to the intrusive complexes typical of the Tunguska syneclise (Katangsky, Kuzmovsky, [53]), the Norilsk area (Ergalakhsky, Norilsk, Daldykansky, Ogonersky) [52], and the local Kureysky complex. However, this classification does not take into account modern geochemical techniques that allow distinguishing different types of intrusive rocks more precisely.
The intrusions occur as sill-like bodies (with a thickness up to 5-6 to 100 m and a length of up to 10-15 km). Rare dykes cut volcanic rocks. The magma intrusion was mainly controlled by Imangdinsky-Letninsky and Khalilsky faults ( Figure 2). Intrusive bodies compositionally vary from olivine gabbro-dolerite to gabbro and leucogabbro. Magnesium-rich rocks (MgO = 9 wt.%) rather occur as separate horizons within differentiated intrusions than forming separate bodies.
The Sr, Nd, and Pb isotope composition of the whole rocks was measured with the aid of a Triton (Thermo) solid-phase multi-collector mass spectrometer in static mode at the A.P. Karpinsky Russian Geological Research Institute VSEGEI Laboratory (Saint Petersburg, Russia). The values used for normalization were 88 Sr/ 86 Sr = 8.375209 and 146 Nd /144 Nd = 0.7219. Preliminary decomposition of silicate samples and separation of elements were performed through a standard method of ion exchange column chromatography. The blank values during the analysis did not exceed 0.1 ng for Sm, Nd, Sr, and 0.05 for Pb, Rb. The isotopic compositions of the standards were JNdi-1: 143 Nd/ 144 Nd = 0.512105 ± 0.000004 and SRM987 87 Sr/ 86 Sr = 0.710250 ± 0.000009. The error of the corresponding isotope ratio was at 95% significance level in absolute values (2 s, abs) or percentages (2 s, %). The model age in millions of years (TMa) corresponds to the evolution model of the Earth's lead composition (Stacey-Kramers, [56]). DM1 and DM2 model ages (in million years) calculated relative to a one-and two-stage model of the mantle neodymium isotope composition evolution. The 87 Sr/ 86 Sr*, 143 Nd/ 144 Nd*, eNd(T) is the initial isotope composition of corresponding sample at the time of its origin (250 Ma).

Results
Here we describe the sedimentary and magmatic rocks of the third site, named the Kulyumber site (Figures 2 and 3) including its western part ( Figure 4). Some intrusive bodies were studied in the cores of the boreholes drilled in the western part of this area, shown in Figure 4.

Sedimentary Rocks
The sedimentary rocks' outcrop is in the western part of the Kulyumber site (Figures 3 and 4), where they form the western part of the Nirungdinsky trough. The Devonian sediments in the Kulyumber river valley dip to east at 10-12 degrees. The thickness of these deposits was 50 m. They consist of brown-red crimson, coarse-grained marls, and dark grey limestones, combined in the Nakokhozsky formation [57]. The chemical compositions of four representative samples (Kul-8-Kul-11, Table 1) had different SiO 2 /CaO (wt.%) ratio varying from 0.04 to 2.01, which reflects admixture of terrigenous component in carbonate rocks. The high SiO 2 and MgO contents are typical of marls (Table 1, Nos. 1 and 2) while low SiO 2 and absence of MgO in rocks correspond to limestones. The contact of the Devonian deposits with overlain rocks was intruded by gabbro sills but it is described as subconformed [57]. The Tunguska Group of rocks (C 2 -P 2 ) comprises terrigenous rocks with coal horizons belonging to the Burguklinsky formation in this area. It is widespread in the Kulyumber river valley and consists of dark-grey, layered argillite, siltstone, and sandstone. We studied these rocks in the Khalil river valley (Table 1, Nos. 5 and 6). Quartz dominates in these rocks while carbonate and clay minerals occur as well.  Table 3, oxides are given in wt.%, elements in ppm. Analyses number sites: 1-4 are Kulyumber and 5 and 6 are Khalil; bdl-below detected limit; LOI-loss of ignition. Figure 5 demonstrates the abundance of trace and rare Earth elements in the Devonian and Tunguska Group rocks. All rock samples show similar distribution patterns, though their elemental contents may differ by about two orders of magnitude. They are characterized by the Ta-Nb-negative and U-and Pb-positive anomalies; these features are typical of crust rocks. All rocks were depleted in Ti. The (La/Sm)n ratio ranged from 3.2 to 5.1 and is higher than this ratio in intrusive rocks. The (Gd/Yb)n ratio varied in narrow range from 1.4 to 1.6. The highest elements' concentrations occurred in marls and siltstones, while carbonate rocks were depleted in them. Composition of sedimentary rocks is important for the estimation of assimilation of surrounding rocks by magma during emplacement.
contact of the Devonian deposits with overlain rocks was intruded by gabbro sills but it is described as subconformed [57]. The Tunguska Group of rocks (C2-P2) comprises terrigenous rocks with coal horizons belonging to the Burguklinsky formation in this area. It is widespread in the Kulyumber river valley and consists of dark-grey, layered argillite, siltstone, and sandstone. We studied these rocks in the Khalil river valley (Table 1, Nos. 5 and 6). Quartz dominates in these rocks while carbonate and clay minerals occur as well. Figure 5 demonstrates the abundance of trace and rare Earth elements in the Devonian and Tunguska Group rocks. All rock samples show similar distribution patterns, though their elemental contents may differ by about two orders of magnitude. They are characterized by the Ta-Nb-negative and U-and Pb-positive anomalies; these features are typical of crust rocks. All rocks were depleted in Ti. The (La/Sm)n ratio ranged from 3.2 to 5.1 and is higher than this ratio in intrusive rocks. The (Gd/Yb)n ratio varied in narrow range from 1.4 to 1.6. The highest elements' concentrations occurred in marls and siltstones, while carbonate rocks were depleted in them. Composition of sedimentary rocks is important for the estimation of assimilation of surrounding rocks by magma during emplacement.

Volcanic Rocks
Volcanic rocks form the eastern part of the area, and they occur in the center of the Nirungdinsky trough ( Figure 2). They are represented by the basalts and tuffs that were correlated with volcanic rocks of the Norilsk area. Five formations were recognized within the studied area: Syverminsky, Gudchikhinsky, Khakanchansky, Tuklonsky, and Nadezhdinsky. We studied in detail the structure and composition of the lower part of the lava sequence in the Khalil site and compared it with the lower part of the volcanic section in the Norilsk area (Lake Lama). These data were published earlier [51] and volcanic rocks were not described in this article.

General Characteristics of Intrusive Rocks
As mentioned above, the study area is located at the border of two different tectonic zones (Figure 1), and this led to the formation of intrusive bodies with characteristics resembling both environments. Thus, the classification of these rocks is not straightforward. The geological map (Figures 2-4) shows that this area comprises seven different complexes including: Ergalakhsky, Norilsk, Daldykansky, Ogonersky (typical of the Norilsk area), Kuzmovsky, Kureysky, and Katangsky (typical of the Tunguska syneclise) [50,57]. The intrusive bodies constituting these complexes show similar morphology, texture, and composition. It is very difficult to recognize them without special study, on the basis of only major components in rocks. Along with the major components, we analyzed trace elements in all samples ( Table 2) as well as radiogenic isotopes in some of them.
The intrusions account around 15% of the surface (Figures 2 and 3). They are represented by sills or sill-like bodies located subconsequently in sedimentary rocks (O, S, D, C 2 -P 2 ), i.e., they extend in submeridional direction at 15-20 km and fall to the east at 10-12 • to the center of the Nirungdinsky trough. Several intrusive bodies are dykes cutting volcanic rocks (site 1). The thickness of intrusions varies from 5-10 m to 150 m. Initially on the surface all intrusive bodies were subdivided into three complexes: The Ergalakhsky of elevated alkalinity and Katangsky and Kureysky of normal alkalinity. Fine-grained gabbro-dolerites were attributed to the Katangsky complex while medium-and coarse-grained and weakly stratified rocks (up to leucogabbro) were referred to the Kureysky complex. The rocks of the first complex dominate in the Kulyumber area. The temporal relationships between intrusions of different complexes are unknown because there are no geological boundaries between them because they are separated by sedimentary rocks. Their correlation with lavas was carried out on the bases of their chemical compositions: The Ergalakhsky complex is correlated with Ivakinsky formation due to elevated Ti, alkalis, and (La/Sm)n contents in their rocks. Katangsky and Kureysky complexes are similar to the lavas of the main stage of platform magmatism (Morongovsky-Samoedsky formations). The paleomagnetic data give similar results [59,60]. The most convincing results were obtained for the Ergalakhsksky complex, which is characterized by reverse magnetization like the Ivakinsky formation. Note. *-after [60].
The rocks of the Ergalakhsky, Kureysky, Norilsk, and Katangsky complexes were recognized in outcrops while the Supposed Ogonersky, Daldykansky, Kuzmovsky, Kruglogorsky, and Norilsk subcomplex of the Norilsk complex were diagnosed in the boreholes ( Figure 4, Table 2). To understand the difference between rocks of these complexes, we studied mineral and chemical compositions of rocks from the Kulyumber site and from the reference complexes (Daldykansky, Ogonersky, and Norilsk) in the Norilsk area and Katangsky and Kureysky in the Tunguska syneclise. Within the Kulyumber site ( Figure 3) only one intrusive body had sub-alkaline composition and belongs to the Ergalakhsky complex (Kul-15). Three intrusive bodies were attributed to the Kureysky complex, including the large Intrusion 4 ( Figure 3, samples Kul-16, K-1, K-2), one intrusion in the central part of site (sample Kul-12), and one in its right side (sample Kul-40). According to our geochemical data, these intrusive bodies belong to different complexes (see below).
Intrusions of the Katangsky complex dominate in the area. We studied five sills in the Kulyumber site across their thickness (points Kul-2-7, 13, 14) as well as along their length (Kul- [25][26][27][28][29][30][31][32][33][34][35][41][42][43][44]. Kureysky complex. The largest intrusion of the Kureysky intrusive complex is the Intrusion 4 in Figure 3. It is formed by coarse-grained and middle-grained olivine gabbro-dolerites and gabbro-dolerites. The main rock-forming minerals are olivine, clinopyroxene, plagioclase; moreover, rare minerals are represented by biotite, magnetite, and apatite. Composition of olivine (representative analyses of rock-forming minerals are given in Table 3, full data are in Table S1) varied significantly from Fo 49 to Fo 75 , and the largest grains have a zoned structure where border zones are enriched in Fe (Figure 6a,b). The CaO content reached 0.32 wt.%, and the NiO contents were low (0.05-0.17 wt.%). This composition strongly distinguishes from the olivine compositions of the ore-bearing intrusions of the Norilsk area, in particular, from the Norilsk 1 intrusion (Table 3 and Table S1) and other intrusions [24,25,[61][62][63]. Clinopyroxene has a more stable composition. Its Mg number ranged between 64-74. Chromium is practically absent (at the level of the electron microprobe analysis (EPMA) sensitivity) and TiO 2 content reached 1 wt.%. Maximum concentrations were (wt.%) Al 2 O 3 -2.25 and Na 2 O-0.40. The composition of plagioclase varied from An 56 to An 70 . Magnetite contained 12-14 wt.% TiO 2 . The mineral composition of the Khalil intrusion (the Khalil site), attributed to the Kureysky complex, which was also studied in the samples X-19 and was close to that of Intrusion 4 in the Kulyumber site.    Table 2.
Olivine was found in all varieties of rocks and its composition changed in the range of Fo32-Fo66. Its amount grews towads the lower part of the intrusion from the top (up to 20-25 wt.%). Its morphology also varied. In the lower part it was represented by idiomorphic crystals, while at the top it formed interstitial grains. Clinopyroxene (augite, Mg# 66-68) had a zonal structure where the central parts were enriched in chromium (up to 0.5 wt.% Cr2O3) and border zones contained up to 1.1 wt.% TiO2. Magnetite was similar in composition to magnetite from the Katangsky gabbro-dolerites (it contained up to 12 wt.% TiO2).  Table 2.
We studied some samples from the other intrusions of this complex (Kul-40, Kul-12, Figure 4). The sample Kul-12, taken from the intrusion previously attributed to the Kureysky complex in the geological map [57] and allocated by us in a separate complex [60], consisted of plagioclase and clinopyroxene, forming the poikilophyric structure. The pyroxene has a higher Mg number (77)(78) than minerals from the intrusions described before. Plagioclase was altered to sericite and An 35 dominated in rocks.
The reference object of the Kureysky complex was the Dzhaltulsky massif, located several kilometers to the south from the Kulyumber area, in the Kureyka river valley. We studied three samples from the vertical section of this massif taken from the borehole OKG-13 at depth 43.7, 69.2, and 180.2 m. One sample was taken from the surface (No. 91). Olivine changed in a wide range from Fo 55.7 to 81.6 from the upper part of the massif to its bottom. It was characterized by very low concentrations of calcium and nickel (0.07-0.17 wt.% CaO and 0.03-0.06 wt.% NiO). Pyroxene composition was more stable. Its magnesium number varied from Mg# = 65 to Mg# = 81. It comprised a high Al 2 O 3 content (up to 3 wt.%) and sample 91 was characterized by elevated Cr 2 O 3 , up to 0.12 wt.%.
Intrusions of the Katangsky complex are usually composed of fine-to medium-grained homogeneous gabbro-dolerites and olivine-bearing gabbro-dolerites. They have usually a dolerite, poikilophytic structure ( Figure 6c (Table S1).
Supposed Norilsk complex (Kruglogorsky subcomplex). The massif, named Gabbrovy intrusion, located in the Silurian rocks (to the west from the Kulyumber site, Figure 4) was traced by several boreholes. We studied it in the core of the borehole, PR-1 penetrated at the depths from 213 to 275 m. This intrusive body was weakly differentiated. The main volume of intrusion consisted of olivine gabbro-dolerites with leucogabbro occurring in the upper part and the thickness of 2.5 m. This intrusion was attributed to the Norilsk complex, Kruglogorsky subcomplex, on the basis of the leucogabbro occurrence [45].
Olivine was found in all varieties of rocks and its composition changed in the range of Fo 32 -Fo 66 . Its amount grews towads the lower part of the intrusion from the top (up to 20-25 wt.%). Its morphology also varied. In the lower part it was represented by idiomorphic crystals, while at the top it formed interstitial grains. Clinopyroxene (augite, Mg# 66-68) had a zonal structure where the central parts were enriched in chromium (up to 0.5 wt.% Cr 2 O 3 ) and border zones contained up to 1.1 wt.% TiO 2 . Magnetite was similar in composition to magnetite from the Katangsky gabbro-dolerites (it contained up to 12 wt.% TiO 2 ).

Chemical Composition of Intrusive Rocks
Major components. Most of the analysis (Figure 7a, Table 4) fell in the field of basalts of normal alkalinity basalts, a number of them were located in trachybasalt and basaltic trachyandesite fields, and only several points occurred in the field of picritic basalts (Dzhaltulsky massif and Norilsk 1 intrusion). A similar distribution was observed in the SiO 2 -MgO diagram (Figure 7b), where only some rocks had high Mg compositions (23-28 wt.% MgO) that did not belong to the Kulyumber area. Therefore, we limited further consideration of the compositions of the rocks from the Kuyumber area with MgO contents of 2-12 wt.% ( Figure 8). This restriction allowed us to consider the obtained data in more detail.    n/a n/a n/a n/a n/a n/a n/a n/a S <0.05 <0.05 <0.05 n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a   V  312  261  271  273  304  342  327  364  298  303  244  Cr  204  145  242 n/a n/a n/a n/a n/a n/a n/a n/a

Chemical Composition of Intrusive Rocks
Major components. Most of the analysis (Figure 7a, Table 4) fell in the field of basalts of normal alkalinity basalts, a number of them were located in trachybasalt and basaltic trachyandesite fields, and only several points occurred in the field of picritic basalts (Dzhaltulsky massif and Norilsk 1 intrusion). A similar distribution was observed in the SiO2-MgO diagram (Figure 7b), where only some rocks had high Mg compositions (23-28 wt.% MgO) that did not belong to the Kulyumber area. Therefore, we limited further consideration of the compositions of the rocks from the Kuyumber area with MgO contents of 2-12 wt.% (Figure 8). This restriction allowed us to consider the obtained data in more detail.  40 41 42 43 44 45 46 47 48 49 50 51 52 53 54     Analysis of behavior of the major elements in the rocks (Figure 8) indicated the presence of two groups of rocks which differed in silica and alkali contents: The Ergalakhsky complex was characterized by the highest concentrations of titanium, potassium, and phosphorus and low silica and calcium in comparison with the other rocks, the points of composition which were plotted close together. According to the TiO 2 concentrations, rock compositions from different intrusions formed a single negative trend (Figure 8a) of the titanium depending on the MgO concentrations, which may be due to the fractional crystallization of a single magma. A similar behavior was observed for F 2 O 3 , although the composition points had a much larger spread (Figure 8b). In both cases, the Norilsk 1 massif had the lower content of these elements, which distinguishes it from other rocks, including the Gabbrovy intrusion, referred to as the Kruglogorsky subcomplex of the Norilsk complex ( Figure 9). Thus, the weighted mean TiO 2 content in the Gabbrovy intrusion was 1.35 wt.% (Table 4), while its average mean content in the Norilsk 1 intrusion was 0.87 wt.%, i.e., <1 wt.% that is typical of the ore-bearing massifs in the Norilsk area [18,65,66]. According to these oxides, this massif could be attributed to the Katangsky complex. One spectrum in the Gabbrovy intrusion (sample PR-1/224, MgO = 4.44 wt.%) is dramatically enriched in trace elements, i.e. their contents are 3 times higher than the contents in Mg-rich rocks (sample PR-1/962, MgO = 9.21 wt.%) and it was characterized by negative Sr anomaly, which was absent in other patterns. The rocks of similar composition from the Norilsk 1 intrusion had no similar enrichment in trace elements (for example, DM-27/46, MgO = 4.51 wt.%) and had positive Sr anomaly. We suggest the occurrence of xenolith of any rocks or late sill inside the Gabbrovy intrusion because the behavior of major trace elements did not support the theory of the origin of this sample as a result of fractionation crystallization. The Dzhaltulsky massif (Figure 10e), despite its similarities with the Norilsk 1 and Gabbrovy intrusions, had some differences, i.e., smaller Ta-Nb anomaly and Th and U contents, and strong positive Pb anomaly (despite the absence of sulfides in these samples).  A slightly lower content of MnO is also typical of the Norilsk 1. The CaO and Al 2 O 3 demonstrated opposite trends, i.e., they directly correlated with MgO contents (Figure 8c,d). Points of the Na 2 O concentrations formed two trendlines; one of them was typical of the Norilsk and Kureysky complexes and the second line characterized distribution of this oxide in other rocks (Figure 8e). The highest K 2 O and P 2 O 5 contents (Figure 8f,g) were typical of the Ergalakhsky and Kulyumbinsky complexes that distinguish them from the other rocks.
For studyng for Kuyumber river it is important valley to compare two complexes that were most widespread: Katangsky and Kureysky. The last named complex was attributed to the Dzhaltulsky massif. We used samples from this massif. The data showed (Figure 8) that there was no difference between the Kureysky intrusive bodies and Katangsky intrusions while the Dzaltulsky massif differed in low TiO 2 , high Mg, high Al, and low alkalis. The Supposed Kuzmovsky complex was similar to the Katangsky intrusions.
Trace elements. The distribution of trace elements in rocks from different intrusive complexes is shown in a series of spider diagrams (Figure 9), as well as in binary diagrams that reflect the main features of the spectrum topology ( Figure 10). There were 3 types of spectra that were fundamentally different from each other: (1) Without Ta-Nb and Pb anomalies characterized by a strong slope of the right part of the spectrum (Gd/Yb)n = 2.1, samples Kul-12, Kul-12/1 (Figure 9a). We attributed this intrusion to a new Kulyumbinsky complex.  Figure 9c shows patterns for the Katangsky complex. The lowest concentrations of trace elements in this type were typical of the rocks of the Dzhaltulsky massif and picritic gabbro-dolerites from the Norilsk 1 massif, due to the large amount of olivine in the rocks.
Thus, the third group included many intrusions of similar composition in terms of major components but differed in trace elements. These differences reflect the value of anomalies (Ta-Nb, Pb, Sr, and Ti) and inclination of patterns on the X axis. Figure 10 demonstrates the difference between the spectra of the rocks from different complexes belonging to the third group. First of all, it was important to compare the rocks of the Norilsk complex from the Norilsk area and the rocks preliminary data attributed to this complex rocks of the Gabbrovy intrusion (Figure 10a,b). Both intrusions had similar spider diagrams and a big difference in trace elements' contents between high-Mg and low-Mg varieties, with total trace element contents changing 2-3 times.
One spectrum in the Gabbrovy intrusion (sample PR-1/224, MgO = 4.44 wt.%) is dramatically enriched in trace elements, i.e. their contents are 3 times higher than the contents in Mg-rich rocks (sample PR-1/962, MgO = 9.21 wt.%) and it was characterized by negative Sr anomaly, which was absent in other patterns. The rocks of similar composition from the Norilsk 1 intrusion had no similar enrichment in trace elements (for example, DM-27/46, MgO = 4.51 wt.%) and had positive Sr anomaly. We suggest the occurrence of xenolith of any rocks or late sill inside the Gabbrovy intrusion because the behavior of major trace elements did not support the theory of the origin of this sample as a result of fractionation crystallization. The Dzhaltulsky massif (Figure 10e), despite its similarities with the Norilsk 1 and Gabbrovy intrusions, had some differences, i.e., smaller Ta-Nb anomaly and Th and U contents, and strong positive Pb anomaly (despite the absence of sulfides in these samples).
The rocks from the other intrusive complexes of the third group from the Kulyumber river valley, Norilsk area, and Tunguska syneclise were characterized by different spider diagrams that we demonstrate in Figure 10 for clarity because they have visible differences. The most widespread complexes were Katangsky and Kureysky in the studied area. The first complex comprised sills of gabbro-dolerites and olivine gabbro-dolerites boarding the lavas area of the Siberian trap province.
These intrusions had thickness varying from one to to 400-500 m. We studied intrusion from this complex outside the Kulyumber river valley, i.e., Padunsky sill in the Angara river valley [29], as well.
gabbro-dolerites and olivine gabbro-dolerites boarding the lavas area of the Siberian trap province. These intrusions had thickness varying from one to to 400-500 m. We studied intrusion from this complex outside the Kulyumber river valley, i.e., Padunsky sill in the Angara river valley [29], as well.
The geochemical features of these intrusions (Figure 10i) were close to the features of the Katangsky (Figure 10c) and Kureysky (Figure 10d) complexes in the Kulyumber site. The rocks of the Daldykansky and Ogonersky complexes located in the Norilsk region differed significantly from those described above (Figure 10f,j). Thus, the rocks preliminarily attributed to these complexes within the Kulyumber area clearly do not belong to them (Figure 10g,h).  A more thorough analysis of the spider diagrams used the ratio of a number of elements that reflected the topology of the spectra (Figure 11). These main relationships included (La/Sm)n, (La/Yb)n, and (Gd/Yb)n, reflecting the overall slope of the spectrum, as well as its individual parts, including the behavior of rare Earth elements in rocks. The U/Nb ratio (or Th/Nb) characterizes the value of Ta-Nb anomalies. The diagram (La/Sm)n -(Gd/Yb)n ( Figure 11a) shows that all intrusions are subdivided into three groups, as noted above. The first two groups included the Ergalakhsky and Kulyumbinsky complexes that were characterized by similar high (Gd/Yb)n ratio (1.9-2.1) and elevated (La/Sm)n value, which was higher for rocks of the Ergalakhsky complex in comparison with this ratio in the Kulyumbinsky complex (2.6-2.9 and 1.9-2.0, respectively). The third group was represented by several intrusive complexes with similar parameters. But these intrusions showed certain differences among themselves in the (U/Nb)n ratio (Figure 11b,c), and a significant difference from the rocks of the first and second groups (Kulyumbinsky and Eergalakhsky complexes), characterized by minimal values of this ratio.
The rocks of the third group formed a wide range of compositions, varying in (U/Nb)n ratio. A more detailed examination of these rocks (Figure 11c) indicated that there were intrusions with high, low, and intermediate (U/Nb)n ratios, reflecting the most pronounced Ta-Nb anomaly, the minimum pronounced, and ordinary apparent. The highest (U/Nb)n ratio was typical of the Supposed Kuzmovsky and Supposed Daldykansky complexes penetrated by PR-4 and PR-11 boreholes. One sample from the Gabbrovy intrusion (PR-1/224) has a high (U/Nb)n ratio, as well, and occurred in the same field which supports its xenogenous origin in comparison with the other samples from this intrusion. The lowest (U/Nb)n ratio characterized the Daldykansky and Ogonersky complexes  Table 3 (Figure 10d) complexes in the Kulyumber site. The rocks of the Daldykansky and Ogonersky complexes located in the Norilsk region differed significantly from those described above (Figure 10f,j). Thus, the rocks preliminarily attributed to these complexes within the Kulyumber area clearly do not belong to them (Figure 10g,h).
A more thorough analysis of the spider diagrams used the ratio of a number of elements that reflected the topology of the spectra (Figure 11). These main relationships included (La/Sm)n, (La/Yb)n, and (Gd/Yb)n, reflecting the overall slope of the spectrum, as well as its individual parts, including the behavior of rare Earth elements in rocks. The U/Nb ratio (or Th/Nb) characterizes the value of Ta-Nb anomalies. The diagram (La/Sm)n-(Gd/Yb)n (Figure 11a) shows that all intrusions are subdivided into three groups, as noted above. The first two groups included the Ergalakhsky and Kulyumbinsky complexes that were characterized by similar high (Gd/Yb)n ratio (1.9-2.1) and elevated (La/Sm)n value, which was higher for rocks of the Ergalakhsky complex in comparison with this ratio in the Kulyumbinsky complex (2.6-2.9 and 1.9-2.0, respectively). The third group was represented by several intrusive complexes with similar parameters. But these intrusions showed certain differences among themselves in the (U/Nb)n ratio (Figure 11b,c), and a significant difference from the rocks of the first and second groups (Kulyumbinsky and Eergalakhsky complexes), characterized by minimal values of this ratio.

Isotope Composition of Intrusive Rocks
To characterize the initial isotope composition for the main intrusive complexes of the Kuluymber river valley, we analyzed Sr, Nd, and Pb isotope systems of representative samples from the Ergalakhsky, Kulyumbinsky, Kureysky (Khalil intrusion), Supposed Norilsk-type (the Khalil site), and Gabbrovy intrusion. The obtained results for 11 whole-rock samples of mafic intrusions and The rocks of the third group formed a wide range of compositions, varying in (U/Nb)n ratio. A more detailed examination of these rocks (Figure 11c) indicated that there were intrusions with high, low, and intermediate (U/Nb)n ratios, reflecting the most pronounced Ta-Nb anomaly, the minimum pronounced, and ordinary apparent. The highest (U/Nb)n ratio was typical of the Supposed Kuzmovsky and Supposed Daldykansky complexes penetrated by PR-4 and PR-11 boreholes. One sample from the Gabbrovy intrusion (PR-1/224) has a high (U/Nb)n ratio, as well, and occurred in the same field which supports its xenogenous origin in comparison with the other samples from this intrusion. The lowest (U/Nb)n ratio characterized the Daldykansky and Ogonersky complexes (Norilsk area), Norilsk-type intrusion in the Khalil site, and Dzaltulsky massif. The rock compositions of the Norilsk 1 intrusion, Gabbrovy intrusion, and Katangsky and Kureysky complexes formed a single field, where points of the Khalil intrusion occurred at the edge of this field.

Isotope Composition of Intrusive Rocks
To characterize the initial isotope composition for the main intrusive complexes of the Kuluymber river valley, we analyzed Sr, Nd, and Pb isotope systems of representative samples from the Ergalakhsky, Kulyumbinsky, Kureysky (Khalil intrusion), Supposed Norilsk-type (the Khalil site), and Gabbrovy intrusion. The obtained results for 11 whole-rock samples of mafic intrusions and one of argillite from host Tunguska Group are presented in Table 5

Tectonic Structure
In 1936 V. Sobolev [1] performed the first detailed petrographic description of igneous rocks of the Siberian traps province. This publication defined the main directions of intraplate magmatism study for many years. These lines of research included: (1) Study of regional petrochemical provinces

Tectonic Structure
In 1936 V. Sobolev [1] performed the first detailed petrographic description of igneous rocks of the Siberian traps province. This publication defined the main directions of intraplate magmatism study for many years. These lines of research included: (1) Study of regional petrochemical provinces  Note. Nos. 1-11 correspond to the analysis of samples from intrusive complexes: 1, Ergalakhsky; 2, 3, Kulyumbinsky; 4-6, Kureysky; 7-10, Norilsk; 7-9, Kruglogorsky subcomplex; 10, Norilsk-type intrusion; 11, metasomatized gabbro-dolerite; 12, argillite from the Tunguska Group. Ndi, Sri, εNd, and Sri-the initial isotopic compositions of the studied samples (in absolute or relative values-ε) were calculated for the age of 250 Ma and sample 12 for 295 Ma. Color means different rock groups.
Despite these variations, the initial isotopic signatures of the samples studied were characterized by high consistency inside the intrusive complexes and, at the same time, they differed significantly between these complexes. Thus, the rocks of Ergalakhsky complex had an initial strontium ratio value (Sri) at 0.7060 and lowest epsilon neodymium value, −3.8, while the rocks of the Kulyumbinsky complex were characterized by Sri 0.7067 and epsilon neodymium at −1.0, and the Gabbrovy intrusion had the lowest Sri values, from 0.7049 up to 0.7052, and the highest epsilon neodymium, from +1.0 up to +2.2 ( Figure 12). While the metasomatized sulfide-containing basalt of the Katangsky complex had initial isotopic parameters that were almost identical to the sedimentary rocks of the Tunguska Group, namely, Sri 0.7082 for basalt (X-15-2) versus 0.7088 for argillite (X-47-2) and εNd-2.7 for basalt and −3.2 for argillite. The studied samples of the Kureysky complex had the most variable isotopic characteristics, so the initial isotopic composition of strontium varied from the lowest value among the studied samples, 0.7048, to one of the highest, −0.7070. In this case, the isotopic composition of neodymium varied within 2 units of epsilon, from +0.4 to +2.3. Perhaps these variations, which are atypical for other complexes, are explained by a combination of separate intrusions genetically belonging to other intrusive complexes (e.g., Intrusion 4 and Khalil intrusions).
It should be noted that the initial isotopic characteristics of intrusive complexes from the Kuluymber river valley were close to those obtained previously for the complexes of the same name sampled in other areas of the Norilsk region. Thus, the subalkaline trachydolerites of the Ergalakhsky complex from the northern and southern parts of the Norilsk district had neodymium composition nearly the same: εNd within −3.8 and −4.2 [67][68][69] and only the initial strontium isotopic composition, 0.7064-0.7075, was slightly higher than the value we measured in sample X-40.
Mafic rocks of the Kruglogorsky subcomplex of the Norilsk intrusive complex were characterized by weakly positive values of neodymium epsilon, from +1.5 to +2.2, and strongly varying strontium isotopic compositions, from 0.7062 to 0.7084 [67], while the Supposed Kruglogorsky subcomplex of the Norilsk complex in the Kulyumber river valley (Gabbrovy intrusion) had a comparable isotopic neodymium composition (from +1.0 to +2.2) and significantly less radiogenic compositions of strontium, 0.7048-0.7052, which apparently is associated with steadily low rubidium content in these rocks. Thus, at first glance, the initial isotopic characteristics of the Gabbrovy intrusion rocks did not contradict the assumption that they belong to the Norilsk complex (Kruglogorsky subcomplex).
Alternatively, a separate local mantle source could exist for the Kulyumbinsky intrusive complex, which differed in composition both from the sources of the Norilsk type and from the Ergalakhsky subalkaline type of intrusion. The fact that it was rather a separate mantle source is also suggested by the specificity of the lead isotopic composition ( Figure 13). The rocks of the Kulyumbinsky complex occupied an intermediate position between the Kureysky and Ergalakhsky rocks on the isotopic diagram 206 Pb/ 204 Pb-207 Pb/ 204 Pb, but presented data were limited only by two samples of rocks of the Kulyumbinsky complex, which were almost identical in composition, and we do not know the real scatter of isotopic data for this complex. Nevertheless, there is no doubt over the influence of the host rocks during the formation of sulfide-containing metasomatite upon gabbrodolerite (sample X-15-2). For example, in the Pb-Pb isotope space, it was possible to construct an isochron line on the samples of the Kureysky complex through a sulfide-containing dolerite of sample X-15-2, corresponding to an age of 250 Ma, and the argillite data point also fell on this line ( Figure 13).

Tectonic Structure
In 1936 V. Sobolev [1] performed the first detailed petrographic description of igneous rocks of the Siberian traps province. This publication defined the main directions of intraplate magmatism study for many years. These lines of research included: (1) Study of regional petrochemical provinces within the Siberian platform, (2) determination of the composition of the initial magmas, (3) analysis of magma intra-chamber differentiations, and (4) ore deposits' formation modeling.
The analysis of the different petrographic provinces is given in many works of V. Zolotukhin with co-authors [3,5,7]. The following structural zones were identified: Prieniseysky, Putorana, Tunguska syncline, Predtaimyrsky, and South Taimyr on the basis of the State Geological Survey (1:200,000 scale) and the analytical data were obtained by the authors on the composition of magmatic rocks within the Siberian platform. Magmatism within these zones is controlled by (1) Early Mesozoic swell-like uplifts that underwent inversion in the Late Mesozoic and is associated with ancient (Riphean) rifts (Khantaysko-Rybninsky, Kureysko-Letninsky, Pyasinsky), (2) ancient linear structures that did not undergo inversion (Predtaymyrsky), (3) ancient aulacogens regenerated in the pre-Mesozoic period (Vilyuysky, Udzhinsky), and (4) early Mesozoic troughs (within the Tunguska syneclise) that did not undergo inversion.
The Prieniseysky zone is the most important tectonic structure which is characterized by a diverse composition of magmatic rocks and high concentration of Cu-Ni deposits. It includes [70] Khantaika-Rybinskoe and Kureysky-Letninsky zones. The latter is a part of a large submeridional tectonic structure in the border zone of the Siberian craton comprising three sublatitude branches, one of which is located within the Kulyumber river valley.
This structure was identified on the basis of the gravimetric mapping of 1:200,000 scale and airmagnetic data of 1:100,000 scale [51] and named as the Norilsk-Igarka paleorift earlier [2,71].

Subdivision of Intrusive Rocks
The study of igneous rocks of the Kulyumber river valley and adjacent territories was carried out in the early 1960s in the course of geological mapping. On the basis of the internal structure of intrusive bodies and the distribution of the main components, the Ergalakhsky complex of high alkalinity and four complexes of moderate alkalinity were identified. The latter include (1) Katangsky complex, comprising undifferentiated or weakly differentiated small-to medium-grained intrusions stable in composition (gabbro-dolerites with 6-7 wt.% MgO) and widespread in the frame of the lava field of the Siberian trap province; (2) Kureysky complex, combining differentiated large intrusive bodies of elevated MgO (8-9 wt.%) with troktolite lenses in olivine gabbro-dolerites; (3) Kuzmovsky complex, integrateing weakly differentiated gabbro-dolerite intrusions with ferrogabbro and granophyres in the upper part of intrusive bodies; and (4) Norilsk complex, which includes highly differentiated intrusions with average MgO-10-12 wt.%.
Our geochemical data indicated the presence of four different groups of igneous rocks within the Kulyumber river valley, which includes effusive and intrusive facies: (1) Mafic and ultramafic volcanic rocks of high and moderate magnesium (MgO = 7-12 wt.%) with elevated TiO 2 (1.2-1.4 wt.%) characterized by the absence (or very weakly presence) of Ta-Nb-negative and Pb-positive anomalies and the following geochemical parameters: (La/Sm)n = 1.45, (Gd/Yb)n = 1.89, 87 Sr/ 86 Sr = 0.70544, εNd = +3.9. These rocks had a mantle origin [42] with garnet in their source and belong to the Gudchikhinsky formation.
The special relationships between studied intrusions of these complexes are unclear due to an absence of geological boundaries between them caused by their separated positions. The legend to the State Geological map [53] confirms the earlier formation of the Katangsky complex in comparison with the Kureysky because several dykes preliminarily attributed to the last complex cut the Dzhaltulsky massif and basalts of the Mokulaevsky formation. Paleomagnetic data [60] show evidence that intrusions in the Kulyumber site (mainly Katangsky complex) are coeval with the basalts of the Mokulaevsky-Kharaelakhsky formations. This conclusion correlates with geochemical data showing TiO 2 increasing in basalts during the evolution of platform magmatism in western Siberia (from Tuklonsky to Samoedsky formation [72]). Similar TiO 2 behavior occurred in the intrusive rocks: The earliest intrusions belong to the Norilsk complex (TiO 2 < 1 wt.%), which cuts the Lower Nadezhdinsky formation and include the Dzhaltulsky massif (0.  (Table 5). Nevertheless, two main intrusions, Khalil and Intrusion 4, were not identical. They have some differences in εNd (2.34 and 1.3). Intrusion 4 in the Kulyumber site was very similar to the Gabbrovy intrusion (borehole PR-1) in major and trace elements as well isotope composition.
The Gabbrovy intrusion is of a particular interest in the Kulyumber river valley due to its sulfide mineralization. It is considered as a promising object for the prospecting of Cu-Ni-rich ore. It was attributed to the Kruglogorsky subcomplex of the Norilsk complex on the basis of the occurrence of leucogabbro horizon in its upper zone ( Figure 13). Sill-like bodies of this subcomplex occur in the main ore junctions of the Norilsk region, the Norilsk and Talnakh, along with ore-bearing intrusions. This combination raises the question of the genetic relationship between the Norilsk and Kruglogorsky subcomplexes. This question was first formulated by Likhachev in 1965 [73]. Leucocratic rocks were also present not only in the Kruglogorsky sills but in ore-bearing intrusions as well. These rocks were represented by two varieties: Coarse-grained panidiomorphic rocks, often with massive or porphyric texture, and rocks with ataxitic structure [73][74][75][76]. In both cases, the rocks were enriched in plagioclase, the amount and morphology of which varied. The first variety consisted of short-prismatic plagioclase crystals (70-90 vol.%) and represented anorthosites (with An 65-90 ). The second variety is comprised of more dark-color minerals (pyroxene and olivine, 20-40 vol.%) that are irregularly distributed in rocks and form segregations in 2-10 cm. They were named taxitic gabbro-dolerites. Usually these rocks are described together as leucogabbro. Meanwhile, they had different positions within intrusive bodies and different origins. The first rock variety, in fact, leucogabbro, formed oval or lenticular bodies (between few centimeters and few meters) with clear boundaries in gabbro-dolerites mostly in peripheral zones of ore-bearing intrusions or in their upper and lower parts. The mechanism of their formation was proposed by Likhachev [73,74] and suggests plagioclase accumulation and floatation during its early crystallization in magma when it rises to the surface in a conduit. In a chamber, magma pushes plagioclase mush into peripheral zones forming "inner leucogabbro". Sometimes this mush fills fractures near a chamber and forms "outer leucogabbro". Thus, Likhachev believes that "there was no significant break in the formation of these components of ore-bearing intrusions (i.e., leucogabbro and gabbro-dolerites of main intrusive body, N.K.), there is no doubt that they belong to a single magmatic system" (page 10 in [74]). Thus, inner leucogabbro bodies are not xenoliths (as it was written in [62]), because they are products of crystallization of the same magma. In this regard, external leucogabbro are apophyses of ore-bearing intrusions. The compositions of internal and external leucogabbro are identical in terms of the main components (Table 7). A similar idea on the origin of the Kruglogorsky leucogabbro belongs to Rad'ko [72], who assumes that the occurrence of the Kruglogorsky intrusions in any places is evidence to the location of ore-bearing intrusions nearby. On the basis of this suggestion, the Kruglogorsky sills can be used for prospecting new Cu-Ni deposits. This approach formed a special geological method, which has been used by Norilskgeology Ltd. within the Kulyumber river valley. In this regard, the Gabbrovy intrusion is an indicator of closely located mineralization.
The second variety of leucogabbro with ataxitic structure formed horizons in the lower and upper zones of intrusions. They had a large thickness and comprised economic PGE-Cu-Ni mineralization in the ore-bearing intrusions (Talnakh, Norilsk 1). Their origin has been under discussion for many years [75,77,78].
Meanwhile, the geological mapping and exploration carried out in the 1960s and 1970s, demonstrated that the outer leucogabbro formed separate intrusive bodies [53]. Although the composition and structure of the Gabbrovy intrusion were similar to those of the Kruglogorsky sills, there are several differences with them. It is enriched in TiO 2 and MgO and depleted in Al 2 O 3 in comparison with the leucogabbro sills of the Norilsk region (1.35 and 1.05 TiO 2 , 7.6 and 6.7 wt.% MgO, 14 and 17-18 wt.% Al 2 O 3 , respectively) and has different weighted mean composition and isotopic characteristics (Table 6). In fact, the Gabbrovy intrusion takes an intermediate position between the Kruglogorsky subcomplex and Katangsky complex. We guess that it is possible to regard it within the latter as a weakly differentiated body.
In the case of the Kruglogorsky subcomplex sills in the Norilsk region, it was obvious that they were formed from magmas differing in chemical composition from magmas of ore-bearing intrusions. Their parental magmas were more leucocratic (5-6% wt.% MgO in comparison with 10-12 wt.% MgO for the Norilsk ore-bearing intrusions) and had higher εNd and lower Sr ( Table 6). These features cannot be explained by the operation of fluids, as suggested in article [62]. The authors did not give any data on H 2 O, Cl, or F contents in magmas that could support this theory. Furthermore, the occurrence of amygdales in leucogabbro does not account for the enrichment of these rocks by volatile components because amygdales are typical of any rocks in the upper parts of subvolcanic intrusive bodies, not only in the Norilsk region but around the Siberian trap province.
The chemical compositions of rock-forming minerals from the studied intrusive complexes were very close to each other. In general, they reflected the composition of rocks, in particular, their magnesium number. The most significant mineral was olivine, since it is usually an early liquidus phase in rocks. Olivine varied significantly in differentiated intrusions. This has been established in numerous studies for the Norilsk ore-bearing intrusion, where its composition changes from 40 to 82 [24][25][26]43]. Most of the magnesium olivine compositions are typical of the picritic gabbro-dolerites and troctolites, in particular, for these rocks from the Norilsk 1 massif, studied by us in the core of the DM-27 borehole (Figures 14 and 15), where the forsterite component reached 80 mol.%. These olivines were similar to olivines from the Intrusive 2 of the Kureysky complex, changing from Fo 38 to Fo 75 (Table S1). Meanwhile, the Norilsk-type intrusion in the Khalil site, attributed preliminarily to the Norilsk complex, contained very ferruginous olivine Fo [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] . Although the olivines from the Norilsk 1 intrusion were enriched in NiO (especially those from the picrite gabbro-dolerites containing sulfide ores), the olivines from the Intrusion 2 did not differ from them: They were even more nickel-rich at the same Fo. The minimum NiO occurred in the rocks from the Dzhatulsky massif and the trachydolerites of the Ergalakhsky complex. Most of the compositions of studied pyroxenes ( Figure 16) almost all fell into the field of magnesium-rich augite and their points formed a small field in the En-Wo-Fs diagram. As in the case of olivine, pyroxenes from Intrusive 2 of the Kureysky complex were characterized by the greatest dispersion of compositions.     The difference in sources at various depths was explained by an action of fluids as well [83]. Results of nonisothermal equilibrium physicochemical dynamics modeling show the occurrence of the following sequence of zones in over-asthenosphere continental mantle: (1) a zone where initial rocks were intensively sublimated and depleted by most petrogenic components; the restite in this case becomes carbonated, salinated, and graphitized; (2)

Magma Sources
It should be assumed that the four groups of rocks mentioned above have various magma sources. The problem of the magma sources diversity has been considered for the Siberian platform for many years. Initially it was believed [1] that the diversity of all rocks in the province was due to the result of crystallization differentiation of a single magma. By the end of the 1980s, the diversity of rock compositions was explained by the fractionation of the primary picritic magma, resulting from the assimilation of crustal rocks and the influence of mantle fluids on the initial melt [5]. New geochemical data, including a distribution of rare elements in magmatic rocks and their isotopic characteristics, led to a new interpretation of the origin of igneous rocks in the Siberian platform. They were regarded as a product of crust contamination (up to 25-30%) by primary mantle magma [35,36]. Later, the formation of different rocks was explained by simultaneous plume melting of at least two different lithospheric substrates [79,80] or as a result of the action of two different plumes [41]. The variety of rocks was also explained by the different amount of pyroxenite component in the source, formed as a result of the interaction of peridotite with the substance of recycled oceanic crust [81].
The most contrasting compositions of rocks formed at different depths and located in the same place represent tholeiitic basalts and kimberlites that are believed to have been formed from multilevel conjugated sources [82].
The difference in sources at various depths was explained by an action of fluids as well [83]. Results of nonisothermal equilibrium physicochemical dynamics modeling show the occurrence of the following sequence of zones in over-asthenosphere continental mantle: (1) a zone where initial rocks were intensively sublimated and depleted by most petrogenic components; the restite in this case becomes carbonated, salinated, and graphitized; (2) a zone of Si and Fe enrichment and carbon deposition in initial rocks depleted in Na, K, P, and Mn; (3) a zone of diamond-bearing lherzolites enriched with Na; (4) a zone of hydrated rocks enriched with K; (5) a zone of hydrated rocks not enriched with petrogenic components. Zone 2 can be responsible for the formation of kimberlite melts, zones 3 and 4 can be substrates of alkaline magma melting, and zone 5 can be the source of mafic tholeiitic magma. Unfortunately, amount of fluids was not estimated and their role in magma origin is disputable.
So, the spatial combination of rocks formed from different deep sources in the same blocks of crust remains completely unclear. We believe that the complex structure of the northwestern zone of the Siberian platform assumed the presence of faults of different depth which are the conduits for mantle and crustal magmas forming different igneous rocks.
On the basis of the geochemical and mineralogical data on igneous rocks at the Kulyumber river valley given in both parts of the article (Part I and Part II) we came to the following conclusions.

Conclusions
(1) The geochemical study of the volcanic rocks in the Kulyumber river valley allowed distinguishing the following formations similar to those of the Norilsk area: Syverminsky, Gudchikhinsky, Khakanchansky, and Nadezhdinsky. The absence of the Ivakinsky formation in the studied area implied that it pinched out from the north to the south. The tuffs of the Syverminsky formation were analyzed for the first time, and we have demonstrated how they differ from the Khakanchansky tuffs. Basalts of the Gudchikhinsky formation from the Kulyumber area were enriched in alkalis and depleted in U and Th, in comparison with the Gudchikhinsky basalts from the Norilsk area.