Volcanic-plutonic Belt Research Articles

Features of the continental volcanic-plutonic belts of the Junggar-Balkhash fold system

Purpose. The study aims to investigate the formation composition and structural-formation zoning of the Late Paleozoic continental volcanic and volcano-sedimentary formations of the Junggar-Balkhash fold system (JBFS). It also seeks to define the geological-geophysical characteristics and metallogenic specialization of the volcanic-plutonic belts (VPB) in the region. Methods. The research utilizes data from detailed mapping and analysis of Late Paleozoic magmatites in JBFS over the past 10-40 years. Structural-formation zoning of the region was performed from an actualistic perspective, along with the formation typification of stratified and intrusive ore formations. The study of metallogenic specialization was conducted considering modern geophysical research methods. Findings. Two main volcanic-plutonic belts have been identified: the Carboniferous marginal-continental Tasty-Kusak-Kotyryasan-Altunemel Belt and the Carboniferous-Permian intracontinental Balkhash-Ili Belt, which together cover about 80% of the JBFS territory. The geological-geophysical characteristics and metallogenic specialization of these belts have been defined. In particular, the findings highlight significant prospects for epithermal gold-silver and copper-porphyry mineralization. Originality. For the first time, a structural-formation zoning of JBFS has been conducted, and the typification of volcanic-Plutonic Belts has been substantiated. Additionally, their metallogenic specialization has been determined, revealing patterns of localization for epithermal gold-silver and copper-porphyry deposits. Practical implications. The study’s results are of great importance for exploration geology, contributing to the improved efficiency of searching for ore deposits in the region, particularly epithermal gold-silver and copper-porphyry targets.

Iran Desert and Geology for Cultivation Potato

Geology is a branch of Earth science concerned with both the liquid and solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also include the study of the solid features of any terrestrial planet or natural satellite such as Mars. Iran and its neighbouring areas are considered as a complex puzzle, in which continental fragments of various origins were assembled and are now separated by discontinuous ophiolitic belts within the Alpine–Himalayan orogenic system At Kavir Iran central region on the volcanic-plutonic belt of central Iran. It is located in Rafsanjan (Kerman province). Igneous rocks in this area include volcanic rocks (andesite, Trachyandesite, basalt and dacite) and igneous rocks are calc-alkaline magma series. Sedimentary area is limestone, shale, conglomerate, sandstone. Filic and argillic alterations are most prevalent have. According to mineralogical studies, mineralization in this region includes iron oxide minerals, for example; Specularity And limonite, as well as secondary sulfide minerals such as borneite, colitis, digenite, and chalcocite, which are substitutes. Pyrite and chalcopyrite. Mineralization has occurred in the form of diffusion, veinlet, void filling and substitution. Potato is one of the most important legumes and constitutes a dominant portion of the global diet. Finally the effect of water stress. In this study, the potato savalan cultivar (StMYB) was the main factor (sandy, clayey soil, compost) and drought stress in four control levels and -0.3, -0.6, -1, and -1.5 MPa of soil water potential in three replicates form of a split plot. We show that in semnan desert the diversity in germplasm indicated that potato cultivars can be developed for production under certain degrees of drought and soil physical properties.

Discovery, geological setting and mineralization of the Shuvuutai molybdenum deposit, central-southern Mongolia

We document the newly discovered Shuvuutai Molybdenum (Mo) porphyry deposit located in the central-east Mongolian volcanic/-plutonic belt of the southern Altaids. The deposit is characterized by quartz vein- and veinlet-disseminated-type Mo ore bodies mainly hosted in a Late Permian-Early Triassic granitic intrusion. In this study, we provide a detailed study that integrates detailed geology with petrographic, mineralogic, geochemical, and geochronologic date to determine the tectonic setting of the deposit. Fluid inclusion analysis is used to reconstruct the fluid evolution history of the Shuvuutai Mo mineralization system and to understand the origin of the deposit. The ore bodies occur mainly as veins, lenses, and pods in positions from inner intrusions through contact zones to the host rocks distal to causative intrusions. The host rocks are variable in lithology, including granites, porphyries, volcanic breccias and tuffs, and sedimentary rocks. Outward from ore bodies to host rocks, the wall rock alteration is zoned from potassic (K-feldspar-quartz-mica), through phyllic (quartz-sericite-chlorite-epidote), to propylitic or argillic alterations. Two samples from porphyry stock intrusions at Shuvuutai were selected for U–Pb zircon geochronology and trace element composition studies, including the ore-hosting monzodiorite porphyry and quartz syenite porphyry. Our new ages are consistent with, or slightly postdate published zircon U-Pb ages of early phase of monzodiorite porphyry (268–232 Ma) and the main phase of quartz syenite porphyry (251.6 ± 1.7 Ma). Hydrothermal mineralization generally includes four stages, from early to late, represented by (1) potassic feldspar-quartz veins or veinlets, (2) quartz-molybdenite stockworks, (3) quartz-sulfide stockworks, and (4) quartz ± carbonate veins or veinlets. The ore-forming fluids were initially magmatic in origin and show high-temperature and high-salinity, containing daughter mineral and CO2-bearing fluid inclusions; and eventually evolved to low-temperature, low-pressure, low-salinity and CO2-poor meteoric water. S isotopic compositions of sulfides from the Shuvuutai Mo porphyry deposit indicate that the source of the ore-forming material was derived from the felsic magma. The Central-Eastern Mongolian volcanic-plutonic belt continues from Mongolia into northeast China, where similar Mo deposits are not yet recognized, suggesting that a new exploration strategy, based on the characteristics and history of the Shuvuutai discovery, is needed for the Chinese segment of the Altaids.

Geodynamics and Early Cretaceous Magmatism of the Northern Volcanic-Plutonic Belt of Verkhoyan-Kolyma Fold Area (Northeastern Russia)

New data on the geological position, U‒Pb SIMS zircon ages, petro-geochemical features, Sr‒Nd isotopic composition and geodynamic setting of the granitoids and volcanites of the Northern volcanic-plutonic belt, Verkhoyan-Kolyma fold area, are presented. Magmatites of the belt include granitoids of Elikchan, Kuranakh, Bakyn plutons, composed of elikchansky granite-granodiorite complex, and volcanites of predominantly intermediate-felsic Tumusskaya sequence with subvolcanic bodies of the same composition. They form single Early Cretaceous (127–121 Ma) volcanic-plutonic assemblage. Granitoid plutons are elongated in sub-latitudinal-northwestern direction and are discordant to main fold and thrust structures. Granitoids intrude and metamorphose Jurassic terrigenous and Early Cretaceous volcanites of Tumusskaya sequence and are cut by younger Late Cretaceous subvolcanic bodies. Granitoids of Bakyn, Elikchan and Kuranakh plutons combine petro-geochemical features of I-, S- and A-type granites. Such diversity of petro-geochemical granitoid types as well as interrelations of major (\({\text{F}}{{{\text{e}}}_{{\text{2}}}}{\text{O}}_{3}^{{{\text{tot}}}}\)–TiO2–MgO) and rare (Ba/La–Nb × 5–Yb × 10) elements in granitoids and the same age volcanites of Tumusskaya sequence allow to refer them to magmatites of transform margin or plates translation boundaries. Collision between Chukotka microcontinent and Siberian continent with earlier accreted Kolyma-Omolon microcontinent in Barremian-Aptian time changed to post-collisional extension and formation of volcanic-plutonic assemblage of the Northern volcanic-plutonic belt. Post-collisional extension took place in the regime of plates translation boundaries. Sr–Nd isotopic characteristics of granitoids of all plutons indicate the interrelation of mantle and crustal sources of granitoid melts in this process.

Ediacaran and Cambrian Volcanogenic and Sedimentary Complexes of Southern Ulutau (Central Kazakhstan): Structure, Substantiation of Age and Setting of Formation

The article presents the results of studying and substantiating the age of the Ediacaran volcanogenic-sedimentary and Cambrian sedimentary strata isolated for the first time within the southern part of the Ulutau terrane (Southern Ulutau) in the west of Central Kazakhstan. Age Estimates (SHRIMP II) obtained 594 ± 3, 594 ± 5, 600 ± 2 Ma for effusive and tufogenic rocks, as well as their isotope-geochemical characteristics, are the first evidence of the manifestation of Ediacaran suprasubduction magmatism in the paleozoics of Kazakhstan and the Northern Tien Shan. The data obtained indicate the participation of the Ulutau terrane at the end of the Precambrian in the structure of the volcanic-plutonic belt, fragments of which are also Neoproterozoic blocks within Southwestern Kazakhstan (the Zeltava and Chui‒Kendyktas terranes) of the Southern Tien Shan and the Karakum‒Tajik terrane. The formation of the Ediacaran suprasubduction belt may be a continuation of the evolution of the Neoproterozoic active continental margin that arose in the Tonian period on the northwestern margin of the supercontinent Rodinia.

Geodynamic aspects of the metallogeny-magmatic zonality relationship of orogenic volcanic-plutonic belts

Research subject. The orogenic marginal-continental and collisional volcanic-plutonic belts, and the zonality of magmatism and metallogeny within them, as well as the relationship of endogenous metallogeny with magmatic zonality and geodynamics of belt formation.Materials and methods include the long-term studies of the Devonian and Upper-Paleozoic belts of Kazakhstan and the Cretaceous-Paleogenic belt of Sikhote-Alin; an analysis of the alterations in the material parameters of magmatites; the identification of the front and rear parts of the belts and the arrangement features of metallogenic zones within their limits; and the data on other belts of the world.Results. For the marginal continental belts, an asymmetric change of the tholeiitic and low-potassium magmatites of the calcareous-alkaline petrochemical series of the frontal zone of the belt into the magmatites of the high-potassium branch of the calcareous-alkaline and shoshonite series of the rear zone (Devonian and Upper Paleozoic belts of Kazakhstan) has been established. In the same direction, the elemental, as well as the genetic type of deposits changes: pyrite copper-polymetallic frontal zones are replaced by molybdenum-copper-porphyry rear zones (near the border with the frontal zone) and then by rare metal ones. This is also characteristic of the Andean and Okhotsk-Chukchi belts. The collision belts are characterised by symmetrical zonality with a change from rare metal deposits in the centre to copper-polymetallic deposits at the edges (Mongolia). In some cases (Sikhote-Alin and Japan), the continuity of the marginal-continental belt is disrupted as a result of the mantle diapir (or plume), symmetrical magmatic and metallogenic zonality occurs with the change of polymetallic manifestations (near the ocean–continent boundary) to rare-metal ones in the distance. Conclusions. The change in the material parameters of the magmatites of the marginal-continental belts correlates with the removal of their ranges from the ocean–continent transition zone to the interior of the latter. In this case, copper-polymetallic pyrite ore formations are replaced by copperporphyry and then by rare metal ones in this direction. This is due to subduction processes. The collision situation is characterised by a symmetrical zonality of material magmatic parameters with respect to the crowding zone and a symmetrical arrangement of metallogenic zones with a change of rare metal deposits in the crowding zone to copper and polymetallic along the frame. These data are important for metallogenic prediction, as well as for palaeotectonic reconstructions.

Geochronology and Petrogenesis of the Gol Mod Massif: Implications for the Geodynamic Evolution of the Orkhon-Selenge Belt, Northwestern Mongolia

The Orkhon-Selenge Belt is a Late Permian to Early Triassic volcanic plutonic belt located in northern Mongolia and is part of the Central Asian Orogenic Belt. The Selenge Complex, which is a part of the Orkhon-Selenge Belt, is a key area for studying the tectonic and magmatic evolution of the Central Asian Orogenic Belt. This study aims to contribute to understanding of the geodynamic evolution of the Orkhon-Selenge Belt by investigating the petrology, geochemistry and geochronology of the rocks in the region. Our results indicate that intrusive rocks were characterized as high-K, Calc-alkaline series and metaluminous to weakly peraluminous I-type granite affinities and their geochemical characteristics are indicating as arc-like geochemical signatures with depleted in elements such as Nb, Ta, Ti and Y and enriched in elements such as Rb, Cs, Th, K and light rare earth elements. Using zircon U-Pb dating, we determined an age of 257.3±0.73 Ma for the alkali granite, suggesting that south-western part of the Orkhon-Selenge Belt formed during the Late Permian time. The Selenge pluton, which is closely related to Erdenet-Ovoo porphyry type mineralization, is a composite intrusion. However, the zircon grains display magmatic and low oxygen fugacity conditions, which characteristics are likely the effect of weak mineralization of magma ascent with Late Permian tectonothermal event in the south-west part of the Orkhon-Selenge Belt. The results of this study will provide insights into the formation and evolution of the north-western segment of the Mongol-Okhotsk Belt, and will have implications for our understanding of the tectonic history of this region.

Permian–Triassic magmatic rocks in the Middle Gobi volcanic-plutonic belt, Mongolia: revisiting the scissor-like closure model of the Mongol-Okhotsk Ocean

Permian–Triassic magmatic rocks in the Middle Gobi volcanic-plutonic belt, Mongolia: revisiting the scissor-like closure model of the Mongol-Okhotsk Ocean

Tectonic peculiarities of the Zhailma structure formation

Purpose. Studying the genesis and position of the Zhailma trough in the tectonic structures of Central Kazakhstan. Methodology. Critical analysis of literature and stock materials, comparative analysis of geological, geophysical and morphological factors characteristic of continental rifts, features of the formation of volcanic graben synclines, analysis of the results of isotope dating of rocks. Findings. The Zhailma graben-syncline is not an independent structure of the rift origin. The formation of Zhailma is associated with the general evolution of the Sarysu-Teniz segment of the Devonian volcano-plutonic belt. The formation of the Zhailma graben syncline is associated with subsidence after ejections of significant masses of felsic magmatic material. Originality. The authors carried out a comparative analysis of the geological, geophysical and morphological data of the Zhailma structure with similar data characteristic of modern continental rifts. As a result of the analysis, it was established that the rift genesis of Zhailma remains controversial. This structure developed simultaneously with the Devonian volcanic-plutonic belt, and is genetically related to the processes of volcanism. The authors suggest that Zhailma is a volcanic graben-syncline. Practical value. Over a long period of studying the structure, an opinion was formed about the futility of the Sarysu-Teniz segment of the Devonian volcano-plutonic belt for the identification of industrial deposits. An exception was the Zhailma trough, which is a unique Famennian-Carboniferous sedimentary structure in terms of ore saturation, containing significant reserves of iron-manganese, barite-polymetallic and barite proper ores. In this connection, the authors consider it practically important to study the existing graben-synclines in the area of the Devonian volcano-plutonic belt in order to identify industrial deposits of the Atasu type.

Carboniferous magmatic records of central Mongolia and its implications for the southward subduction of the Mongol–Okhotsk Ocean

ABSTRACT The now-extinct Palaeozoic to Mesozoic Mongol–Okhotsk Ocean is evidenced by the Mongol–Okhotsk suture, which stretches from central Mongolia to the Sea of Okhotsk. The geodynamics of southward subduction of the Mongol–Okhotsk Ocean remain enigmatic, especially whether the subduction began during the Carboniferous is highly debated. In this paper we present new zircon U–Pb ages and whole-rock geochemical data for the Carboniferous magmatic rocks in Northeast Mongolia. Zircon U–Pb dating indicates that the Adaatsag dacite, Northern Bayanjargalan gabbro-diorite and Bagannur pluton were emplaced at ca. 325 Ma, ca. 316 Ma, and ca. 305 Ma, respectively. Occurrences of these rocks together constitute a Carboniferous magmatic belt to the northwest of the Middle Gobi volcanic-plutonic belt. The ages of trapped zircon xenocrysts within the Bagannur pluton indicate that the basement of this magmatic belt is the Ereendavaa terrane. Geochemical analysis indicates that these magmatic rocks were formed in an Andean-type active margin, which provides robust evidence for southward subduction of the Mongol-Okhotsk Ocean during the Late Carboniferous. By combining all the available data, we argue that the onset of the Central Mongolia–Tsagaan Uul continental collision during the Late Carboniferous – Early Permian may have triggered the beginning of an active margin of the Mongol-Okhotsk Ocean along the northern coast of the Central Mongolia microcontinent.

PRECAMBRIAN METALLOGENY AND TECTONIC DEVELOPMENT OF THE EARTH’S PROTOCONTINENTS LAURASIA AND GONDWANA

The article explores regularities in the tectonic and metallogenic development of early protocontinents of the Earth (Laurasia and Gondwana) from the time of their appearance during crust and mantle inhomogeneity and disintegration of the united continent Rodinia late in the Proterozoic eon (1.7–0.6 Ga). It also demonstrates the role the formation of ophiolites in Fennoscandia and North American craton belts, as well as the Paleoproterozoic folding and collision structures of Eurasia, South America, and Australia has played in these processes. Another issue considered here is the tectonic and metallogenic significance of the anorogenic granitoid volcanic-plutonic belts and the AMCG association in general, which is especially typical in the Gondwana group of modern continents.

Late Cretaceous granitoids of the Sikhote–Alin orogenic belt, southeastern Russia: implications for the Mesozoic geodynamic history of the eastern Asian continental margin

We present new U–Pb age data for granitoids in the Central Sikhote–Alin orogenic belt in SE Russia, which refute the established opinion about the absence of the Late Cretaceous magmatism at the eastern margin of the Palaeo-Asian continent. It was previously thought that a period of magmatic quiescence occurred from 88 to 50 Ma, related to subduction of the Palaeo-Pacific plate under the eastern margin of the Palaeo-Asian continent, although this is inconsistent with evidence from the Sikhote–Alin, Sakhalin and Japan regions. Three suites of plutonic rocks with different ages were identified in this study. The first suite has ages of 105–92 Ma and formed in a syn-orogenic setting. The second (86–83 Ma) and third ( c. 73 Ma) suites formed during the post-orogenic stage of the Sikhote–Alin orogenic belt. The second and third suites were coeval with Late Cretaceous granitoids that formed in a supra-subduction continental arc known as the Eastern Sikhote–Alin volcanic–plutonic belt. However, the studied rocks are located far inland from the Eastern Sikhote–Alin volcanic–plutonic belt. The ages of the studied granitoids coincide with the timing of a change in the angle of convergence between the Palaeo-Pacific plate and eastern margin of the Palaeo-Asian continent. This change in motion of the oceanic plate with respect to the continental plate was probably caused by a rupture in the subducted slab (i.e. a slab tear), followed by asthenospheric upwelling and partial melting of the overlying crust, which ultimately generated post-orogenic intrusive magmatism. Supplementary material: Laser ablation–inductively coupled plasma–mass spectrometry zircon U–Pb data of the Bikin–Bol. Ussurka granitoid suites are available at https://doi.org/10.6084/m9.figshare.c.5738616

Granitoid-hosted gold mineralization in Ikibzyaksky ore field: a new milestone in Baikal-Patom metallogenic province gold potential study

New data is provided on gold mineralization in the southern Baikal-Patom metallogenic province, Ikibzyakskoye ore field, located in Pravo-Mamakansky deep fault zone separating Patom fold area from Baikal-Vitim volcanic-plutonic belt. For the first time, the metallogenic province was found to comprise granitoid-hosted ore vein-stringer zones with high-grade economic gold sulfide-quartz mineralization. This mineralization is localized within fault shistosity zones manifesting intense beresitization and listvenitization (in metabasite xenoliths).

U-Pb Age, by Zircon, of the Pre-Klesiv Breed Association of the Osnytsky Block

The Osnytsky block is an integral part of the Osnytsky-Mikashevytsky volcanic-plutonic belt, represented by early proterozoic igneous rocks of different compositions. This is a new type of igneous belts for the early precambrian – a paleotypical analogue of intracontinental volcanic-plutonic belts by the phanerozoic, which was formed in the conditions of mature continental crust in the initial stage of radical structural rearrangement of the cratonized gneiss base of the Eastern European platform. Volcanogenic formations have undergone regional metamorphism at a level not higher than the epidote-amphibolite facies, classified in the klesiv series, which combines effusives of basic, acidic and medium composition and occupies a higher stratigraphic position compared to the metamorphites of the teteriv series. Intrusive rocks (gabbro-diorite-granodiorite granite association) – to the osnitsky complex. Rocks of the osnitsky complex are widespread, they account for 80-85% of the area of the Osnitsky block. The pre-klesiv association, represented mainly by gneisses of the teteriv series and plagiogranitoids of the sheremetivsky complex, has a limited distribution. The LA-ICP-MS U-Pb method was applied to date zircon from plagiogranite and plagiomigmatite of the sheremetivsky complex, and from gneiss and amphibolite. The plagiogranite yielded an age of 2110 ± 8, and plagiomigmatite of 2165 ± 22 Ma. Hence, granitoids of the sheremetivsky complex in the Osnitsk block were formed between 2.16 and 2.11 Ga. The age of the metamorphism of gneisses was defined as 2198 ± 29 Ma, whereas zircon from amphibolite crystallized at 1981 ± 36 Ma. Correspondingly, gneiss can be attributed to the teteriv series, whereas amphibolite can belong to either osnitsky complex, or nartsyzivsky complex.

Structural Control of Gold Mineralization of the Central Part of the Malouralsky Volcano–Plutonic Belt (the Polar Urals), Based on an Analysis of Multispectral Images from the Landsat 8 Spacecraft

The central part of the Malouralsky volcanic–plutonic belt, which includes the Manyukuyu–Vorchatinsky ore cluster, is analyzed using multispectral imagery from the Landsat-8 Earth remote sounding satellite with the aim of identifying gold deposits and compared with the Toupugol–Khanmeishor ore region. Similar features in the geological structure and location of deposits and ore deposits in the system of morphological structures are found that should help to develop predictive and prospecting indicators (geological and morphological) of gold mineralization. Three structures are distinguished via analysis of satellite images: the monogenic Novogodnenskaya structure (the Toupugol–Khanmeishorsky ore region) formed under the influence of one main geological process and morphostructures Nos. 1 and 2 (the central part of the Malouralsky volcanic–plutonic belt). These two structures are larger and more complex, with long multistage development. Magmatic chambers are located at depths of ~12 and ~16 km, respectively, for morphostructures Nos. 1 and 2; their root (focal) parts extended southward and then southwestward, respectively, during magmatic development. Prospecting for hydrothermal gold mineralization at the north of the eastern slope of the Polar Urals should be done at the periphery of the centers of large complex morphostructures with long and multistage development with signs of telescoping. Mineralization should be localized in areas of concentration of northwestern and/or northwestern lineaments and in regional fault zones that can be hundreds of kilometers long.

Geochemical characteristics of igneous host rocks of Lubin-Zardeh Au-Cu deposit, NW Iran

The Lubin-Zardeh Au-Cu ± Pb ± Zn deposit is located in the Azerbaijan-Western Alborz zone, 45 km NE of Zanjan, Iran. It is situated within the Eocene-Oligocene volcanic-plutonic belt of the Tarom subzone of the Alborz mountains range. Quartz monzonite and tuffs are the main host rock of the Lubin-Zardeh Au-Cu ± Pb ± Zn deposit. Granitoid rocks are predominantly high- K, calc-alkaline with shoshonitic affinities. They are I-type, metaluminous, magnesian and are characterized by LILE, LREE and Th enrichment relative to HFSE, depletion in Nb, Ta, Ti and weak depletion in HREE and Y. These granitoids show some affinities with adakites, e.g., high Sr/Y and La/Yb ratios coupled with low Yb and Y, and enrichment in LREE and LILE with weak Eu anomalies. Their relatively low to moderate initial 87Sr/86Sr values (0.7047–0.7051), positive Nd (t = 36 Ma) values (0.39–2.1) and TDM ages of 0.69 to 1.06 Ga, with Pb isotopic ratios of initial 206Pb/204Pb = 18.49–18.68, initial 207Pb/204Pb = 15.58–15.61 and initial 208Pb/204Pb = 38.33–38.77, are consistent with a phlogopite-bearing, amphibole-rich, and enriched lithospheric mantle source metasomatized by earlier subducted sediments. The geochemical and isotopic compositions of the granitoids are similar to the host rocks of porphyry and epithermal deposits in the Urumieh–Dokhtar zone.

Tectonic factors of impurity elements accumulation at the Shubarkol coal deposit (Kazakhstan)

Purpose. To study the features of the paleotectonic development of the area and to construct paleotectonic reconstruction of the deposit formation to establish the nature of impurity elements accumulation in the coals and enclosing rocks of the Shubarkol deposit, as well as to increase the mineral resource potential of coals. Methodology. 25 samples of coal and mudstone from the Shubarkol deposit were analyzed. The samples were studied by instrumental neutron- activation analysis (INAA) at the Nuclear Geochemical Laboratory of National Research Tomsk Polytechnic University. Findings. An analysis of geological-structural and paleotectonic formation conditions of the Jurassic coal deposit was carried. The factors of formation of coal and carbon-containing rocks enriched with impurity elements and the conditions needed for its leaching and transportation to the coal seam were analyzed. It was found that the coals in individual samples have average concentrations of Ce, Ba, Sr, Sc, Zn that are higher than the clarke, and Sm, Ce, U, Cr, Yb, Ba, Sr, Nd, As, Sc, Zn, Eu, La in the composition of mudstone have average values that are higher than in coals, and higher than the clarke. It was established that one of the sources of rare-metal mineralization of coals (peat) in the Mesozoic and Cenozoic times were the rock massifs of the Kokchetau uplift in the north and northwest, the Kaptyadyr, Arganatinsk and Ulutau mountains in the west. They form the chain of the Kokchetau-North Tien Shan ancient folded structure and the Central Kazakhstan (Devonian) volcanic-plutonic belt in the east. They surround the sedimentation basin and serve as suppliers of clastic material during the coal-bearing strata formation due to tectonic processes of the Mesozoic-Cenozoic time. Originality. The paleotectonic development of the Shubarkol deposit area during the coal-bearing formation has been reconstructed. It has been established that the Sarysu-Teniz uplift in the Permian-Triassic is separated into an independent block, to which the studied deposit is spatially and genetically related. It has been established that the distribution of elements in the coals of the Shubarkol deposit is determined by the peculiarities of metallogeny, geochemistry of the framing area and the mechanisms of the elements entering the coal seams. Practical value. A purposeful analysis of materials for the peculiarities of high concentrations of impurity elements accumulation in coal in connection with deep fault zones at the Shubarkol deposit serves as an objective justification of the possibility of their integrated use, ensuring the development of the countrys coal industry.

Magmatic control of gold mineralization in Western Primorye (by geophisical data)

An analysis of the regional gravitational field of the north-east of China, Korea and Western Primorye was carried out. The distribution of gold deposits was compared with the development of Mesozoic magmatism and negative anomalies of the gravitational field. Based on the analysis of geological, mineragenic, petrophysical and geophysical materials, geological and geophysical zoning of the western part of the Khanka massif was performed, and a scheme for interpreting geological and geophysical data with elements of minerageny was drawn up. A connection was established between the anomalies of the magnetic and gravitational fields and the position of the supposed gold-bearing ore regions and nodes located in the zone of joints of the North China Triassic-Jurassic volcanic-plutonic belt with the Proterozoic substrates of the Khanka massif. According to geophysical data, Early Jurassic intrusions were identified as, controlling the location of the gold nodes. It was concluded that the gold mineralization is related to the Jurassic magmatism, which increases the prospects for the discovery of gold mineralization in the Khanka district of the Western Primorye.

Detection of Mo geochemical anomaly in depth using a new scenario based on spectrum–area fractal analysis

Detection of deep and hidden mineralization using the surface geochemical data is a challenging subject in the mineral exploration. In this work, a novel scenario based on the spectrum–area fractal analysis (SAFA) and the principal component analysis (PCA) has been applied to distinguish and delineate the blind and deep Mo anomaly in the Dalli Cu–Au porphyry mineralization area. The Dalli mineral deposit is located on the volcanic–plutonic belt of Sahand–Bazman in the central part of Iran. The geochemical data was transformed to the frequency domain using the Fourier transformation, and SAFA was applied for classification of geochemical frequencies and detection of geochemical populations. The very low-frequency signals in the fractal method were separated using the low-pass filter function and were interpreted using PCA. This scenario demonstrates that the Mo element has an important role in the mineralization phase in the very low-frequency signals that are related to the deep mineralization; it is an important innovation in this work. Then the Mo geochemical anomaly has been mapped using the inverse Fourier transformation. This research work shows that the high-power spectrum values in SAFA are related to the background elements and the deep mineralization. Two exploratory boreholes drilled inside and outside the deep Mo anomaly area properly confirm the results of the proposed approach.

Epithermal Mineralization in the Okhotsk–Chukchi Volcano-Plutonic Belt

This paper considers the geochemistry and conditions of generation for the Mesozoic Au–Ag epithermal deposits in the Okhotsk–Chukchi volcanic–plutonic belt (OChVB) in Northeast Russia. We provide new data on the composition and concentrations of trace elements, including REEs, in the ores of epithermal Au–Ag deposits. The ores were found to be enriched in a wide range of trace elements. The REE distributions of these ores are dominated by light “hydrophile” lanthanoids of the “cerium” group. The Eu anomalies were found to vary between high negative to low and high positive levels. Comparative analysis over the classes of gold concentration showed a synchronous enrichment of the ores in similar sets of trace elements. A study of fluid inclusions revealed that the ore-forming solutions had hydrocarbonate potassium or hydrocarbonate sodium compositions. The fluids had high concentrations of sulfate ions for most deposits. The salinity of the fluids was frequently found to increase toward later low-temperature mineralization phases. We identified the tendency of increasing K+ percentage in the fluid from the earlier oreless quartz to productive quartz with increasing depth, as well as some decrease in the percentages of Na+, Ca++, and Cl–. The results indicate magma chambers of andesite magmas and meteoric waters as the most likely sources of the fluids that generated the epithermal Au–Ag ores in the OChVB deposits.