Volcano-plutonic Association Research Articles

Amudzhikan volcano-plutonic association of the eastern part of the West-Stanovoy superterrane (Central Asian orogenic belt): age, sources, and tectonic setting

Amudzhikan volcano-plutonic association of the eastern part of the West-Stanovoy superterrane (Central Asian orogenic belt): age, sources, and tectonic setting

Amudzhikan Volcano-Plutonic Association of the Eastern Part of the West-Stanovoy Superterrane (Central Asian Orogenic Belt): Age, Sources, and Tectonic Setting

Amudzhikan Volcano-Plutonic Association of the Eastern Part of the West-Stanovoy Superterrane (Central Asian Orogenic Belt): Age, Sources, and Tectonic Setting

Geochemical fingerprinting of continental crust trapped in Cadomian volcanic arcs along northern Gondwana

During the Ediacaran to Cambrian periods, the extensive Avalonian–Cadomian accretionary orogen formed along the northern margin of the Gondwana (Pannotia) supercontinent. One of the best-preserved magmatic arcs within this orogenic system is the Davle volcanic complex (DVC) in the Teplá–Barrandian unit of the Bohemian Massif. Using detailed field observations, petrography, major/trace element concentrations, Nd–Hf isotopic compositions as well as U–Pb zircon dating, we interpret a complex evolutionary history of the DVC as comprising three main stages. The first stage (∼610–570 Ma) is represented by a volcano-plutonic association of andesite, dacite, rhyolite and tonalite–trondhjemite–granodiorite (metamorphosed to orthogneiss). A wide range of major/trace element contents together with highly variable εNd values (+3.6 to –5.1) suggest derivation from a juvenile (mantle-derived) source with subsequent assimilation of cratonic crust during magma emplacement, also supported by the modelling of the assimilation–fractional crystallization (AFC) process. The second stage (∼580–560 Ma) is characterized by a gradual termination of the volcanic arc activity, followed by a deposition of marine siliciclastic succession comprising, from the bottom to the top, laminated tuffs, silicified black shales (Lečice Member), and a thick turbidite greywacke–shale–conglomerate sequence (Štěchovice Group). The third stage of poorly constrained age (∼570–500 Ma) is represented by an intra-arc extension and intrusion of juvenile trondhjemite and related rhyolite dykes (εNd +4.8 to +8.4). Finally, we compare these findings with zircon U–Pb ages and whole-rock Nd isotopic data from other Cadomian terranes and propose that the cratonic crust played an important role in recycling along the whole orogenic belt. Thus, we conclude that the Cadomian Orogen formed as a collage of fringing (such as modern Japan, Taiwan, or Philippines) and continental (as modern Andes) arcs of variable evolutionary stages rather than as a belt dominated by intra-oceanic island arcs.

The age and tectonic position epithermal gold mineralization Omolon Massif (North-East Asia)

Some aspects of the genesis of industrially important Paleozoic epithermal gold deposits of the Omolon massif are considered. According to the results of Ar-Ar dating of ores, their age is 20–30 Ma younger than that of the volcanic complexes of the Kedonian volcanic belt of the Devonian, with which this mineralization is traditionally associated. For the Paleozoic continental marginal magmatism of the Omolon massif, we have identified a stage of post-subduction rifting, characterized by the formation of volcano-plutonic associations of shoshonite-latite series. The authors suppose that it was at this stage, the chronological boundaries of which are determined as 335–286 Ma, that the ores under consideration were formed. The paragenetic connection with riftogenic shoshonite-latite series explains such specific features of the Paleozoic epithermal gold mineralization of the Omolon massif, such as high gold-silver ratio, low ore sulfide content, widespread development of fluorite and tellurides, low values of the primary Sr isotope ratio (0,703–0,706).

Petrogenesis of the Despen Volcanic Rocks of the Middle–Late Ordovician Volcanoplutonic Association of the Tannu-Ola Terrane (Southwestern Tuva)

Abstract ––We have studied the structure and composition of a volcanic unit in the valley of the Despen River, on the southern slope of the East Tannu-Ola Ridge. The unit was earlier assigned to the Lower Devonian Kendei Formation. The new geological and geochronological data show that it resulted from explosive volcanism at 460–450 Ma. The Despen volcanic rocks formed in association with granitoids of the Argolik complex at the end of the accretion–collision stage of evolution of the Altai–Sayan region, in particular, the Tannu-Ola terrane. These are predominantly felsic ferroan metaluminous and weakly peraluminous nappe volcanic rocks resulted from the differentiation of tholeiitic basalts. Their REE patterns, like those of the Argolik granitoids, are flat in the HREE, show a distinct Eu anomaly, and suggest magma generation at shallow depths in the upper crust. The magmatic source was of subduction origin, as evidenced by the negative Ta–Nb anomalies in the multielement patterns and by εNd(T) = +3.1 to +5.6, and has a Neoproterozoic model age, TNd(DM-2st) = 0.94–0.69 Ga.

Mykert-Sanzheevka Field of Polycomponent Ores (Pb, Zn, Ag, Au, PGE): Geologic-Substance Characteristics and Formation Features of Ore-Forming System

The new results of geologic-structural, petrographic and mineralogic- geochemical researches of Mykert-Sanzheevka ore field—the Uda-Vitim mineragenic zone South-West ending of West Transbaikalia are given. Its main ore-controlling structure, represented by losange, consisting of rhombohedral and tetrahedral blocks-duplexes mosaic clusters, which are separated by narrow tectonic sutures, is specified. It is clarified that polycomponent ores clusters are confined with these small-block sutures, made by subvolcanic dykes of shoshonite-latite volcano-plutonic association (233 - 188 million years), apodyke dynamometamorphites (breccias, cataclasite, mylonites) and also mechanometasomatites. Four stages of the dynamometamorphites formation characterized by different species compositions of ore minerals appeared as a result of mechanochemical reactions are determined. A carbonyl model of mineral microaggregates formation with films containing noble metal nanoparticles is proposed. Ore-forming system features of Mykert-Sanzheevka field are considered.

Regional, Contact Metamorphism, and Autometamorphism of the Olkhon Terrane (West Baikal Area)

The rocks of the Olkhon terrane experienced high-grade regional metamorphism reaching granulite facies. In addition to regional metamorphism, they were subjected to contact metamorphism and autometamorphism (mafic dikes). Three types of regional metamorphism have been distinguished. A terrane collage north of the Orso Zone revealed two stages of regional metamorphism: early-stage granulite metamorphism (Т = 750–900°С, Р = 8–9 kbar, around 500 Ma) and late-stage amphibolite and low–amphibolite facies (Т = 550–710°С, Р = 4–6 kbar, 460–470 Ma). The Orso microterrane separating the Krestovsky island-arc subterrane from a collage of other microterranes contains high-pressure mineral assemblages (up to 10 kbar), which are characterized by the presence of high-calcium garnet in metapelites. The Orso microterrane and Krestovsky subterrane are characterized by relatively high-pressure path of metamorphism. An extended zone of contact high-temperature metamorphism related to the emplacement of gabbro of the second phase of the Ustkrestovsky Complex has been mapped in the Krestovsky subterrane. The temperature of formation of two-pyroxene hornfels after metaporphyrites of the Birkhin volcanoplutonic association is estimated at 750–850°С. Beerbachites were formed by autometamorphism of subvolcanic mafic bodies, which compose the northern part of the Tazheran composite massif (syenite, Ne-syenite, subalkaline gabbro), dikes in the Birkhin gabbro massif, as well as dikes and separate blocks in marble melange. The temperature of autometamorphism during formation of beerbachites is estimated from two-pyroxene geothermometer as 700–1000°С.

Sources of matter for Neoarchaean subalkaline magmatic rocks of the Keivy structure (Kola Peninsula)

The Neoarchaean subalkaline magmatism of Keivy structure is expressed in formation of the volcano-plutonic association of latite-monzonite-granite (ALMG). The quantity of the measured relation 143Nd/144Nd in rocks is determined in 0.511061-0.511365, and values of model age are located in an interval from 3.14 to 3.21 billion years at εNd (2670) from 2.2 to -1.3. The initial relations 176Hf/177Hf in zircon are in limits 0.280950-0.281069, and figurative points of composition form the field around a trend of the CHUR. According to the isotope and geochemical data for all rocks the basic composition of protholits is supposed. In quantity εHf(T) points of zircon are localized in the field of the development of the crust with 176Lu/177Hf = 0.015 and 3.0-3.3 billion years age. It probably demonstrates the formation of initial melts mainly at the expense of matrix with a long time of stay in crust. The formation of ALMG magmas is assumed to appear due to the melting of metasomatically altered rocks of the lower crust during intrusion of basaltic melts initial for the rocks of the dike complex and the gabbro-labradorite massifs into the upper crust.

Parental Melts of Neoarchean Subalkaline Magmatic Rocks of the Keivy Structure (Kola Peninsula)

The Neoarchean subalkaline magmatism of the Keivy structure is manifested by the emplacement of the latite–monzonite–granite (LMG) volcano-plutonic association. The measured 143Nd/144Nd ratio in rocks is 0.511061–0.511365; the values of model ages fall within the interval of 3.14–3.21 Ga with eNd(2670) varying from 2.2 to –1.3. The initial 176Hf/177Hf ratios in zircon are within the range of 0.280950–0.281069, and composition data points make up a field in the region of the evolutionary trend of the chondritic uniform reservoir. As based on isotope and geochemical data, the protoliths of all rocks are assumed to be basic. In terms of the eHf(T) value, the data points of the zircon composition fall within the domain of the crust with 176Lu/177Hf = 0.015 and an age of 3.0–3.3 Ga. This suggests that the parental melts were probably formed predominantly from material that spent a long time in the crust. The parental melts of the LMG association presumably formed as a result of the melting of metasomatically altered basic rocks during the intrusion into the lower crust of basaltic plutons, which were parental for the rocks of the dyke suite and gabbrolabradorite intrusions in the upper crust.

Rare Earth Elements and Yttrium Potentials of Neoproterozoic Peralkaline Siwana Granite of Malani Igneous Suite, Barmer District, Rajasthan

ABSTRACT The bimodal volcano-plutonic association of Neoproterozoic Malani Igneous Suite of western Rajasthan has resulted in enrichment of rare earth elements (REE), especially heavy rare earth elements (HREE) due to fractionation during polychronous emplacement of riebeckite / aegirine bearing peralkaline granite in three phases. The modal mineralogy indicates bastnasite (La-Ce), parasite, La-Ce-Ba cebaite, cerianite, thorianite, carbocernaite, ancylite, strontianite, celestire, allanite, fergusonite, REE silicates, xenotime, monazite, REE clays and zircon in order of abundance. The distribution of minerals shows total REE minerals 2.04% in Gudanal (east), 2.23% in Gudanal (west), 2.15% in Meli and 2.5% in Bhatikhera. The end phase of magmatic activity represented by boss, dykes and veins of microgranite has rich potentials for HREE. Out of several blocks having preponderance of dykes/veins, Gudanal (east and west), Bhatikhera, Phulan and Meli areas are most promising. The HREE and yttrium abundance of Gudanal (west) is 0.33%, Gudanal (east), 0.22%, Bhatikhera as 0.31% and Phulan 0.93%. Majority of REE minerals are small in size (< 20 microns) occurring as carbonates, followed by phosphates, oxides and silicates and will warrant detailed bulk mineral processing test for the recovery of REE minerals and subsequent metallurgical tests.

Ordovician gabbro-tonalite-trondhjemite complex and associated volcanic rocks in the paleozoic suture between Urals and Kazakhstan

This paper reports new data on the Early Ordovician age established for granitoids of the gabbro-tonalite-trond- hjemite complex in the Denisovka ophiolite zone (suture) on the boundary between the Paleozoic structures (Paleozoides) of the Urals and Kazakhstan. The ages of 482.6 ± 3.6 Ma and 486.2 ± 6.7 Ma were established by the U/Pb method (SHRIMP II) on the age data for zircon extracted from granitoids. The plutonic complex associates with the Early-Middle Ordovician effusive complex, composed of a series of rocks differentiated from basalts to rhyolites. The volcano-plutonic association was formed in the supra-subduction settings, as is evidenced by the composition of the rocks.

Birkhin volcanoplutonic association, Ol’khon region, western baikal area: petrological criteria of comagmatic origin

This paper reports the results of thermodynamic modeling of the formation of the Birkhin volcanoplutonic association by means of geochemical thermometry. The obtained liquid line of descent for the magma chamber of the Birkhin massif indicates that the melt evolved into the field of subalkaline composition. The melts of the volcanics of the Tsagan-Zaba complex are identical to the melts in the magma chamber in both major components and REEs. It was concluded that the Birkhin and Tsagan-Zaba complexes are comagmatic. A scenario was proposed for the development of the Birkhin volcanoplutonic association involving multiple eruptions of volcanic rocks during its formation. It was shown that the intermediate rocks are not derivatives of basic magmas, but were produced by interaction of basic volcanic rocks with felsic intrusions cutting them.

Birkhin Volcanoplutonic Association, Ol’khon Region, Western Baikal Area: Petrological Criteria of Comagmatic Origin

This paper reports the results of thermodynamic modeling of the formation of the Birkhin volcanoplutonic association by means of geochemical thermometry. The obtained liquid line of descent for the magma chamber of the Birkhin massif indicates that the melt evolved into the field of subalkaline composition. The melts of the volcanics of the Tsagan-Zaba complex are identical to the melts in the magma chamber in both major components and REEs. It was concluded that the Birkhin and Tsagan-Zaba complexes are comagmatic. A scenario was proposed for the development of the Birkhin volcanoplutonic association involving multiple eruptions of volcanic rocks during its formation. It was shown that the intermediate rocks are not derivatives of basic magmas, but were produced by interaction of basic volcanic rocks with felsic intrusions cutting them.

The Ordovician Gabbro–Tonalite–Trondhjemite Complex and Associated Volcanic Rocks in the Paleozoic Suture between the Urals and Kazakhstan

This paper reports new data on the Early Ordovician age established for granitoids of the gabbro-tonalite-trond- hjemite complex in the Denisovka ophiolite zone (suture) on the boundary between the Paleozoic structures (Paleozoides) of the Urals and Kazakhstan. The ages of 482.6 ± 3.6 Ma and 486.2 ± 6.7 Ma were established by the U/Pb method (SHRIMP II) on the age data for zircon extracted from granitoids. The plutonic complex associates with the Early-Middle Ordovician effusive complex, composed of a series of rocks differentiated from basalts to rhyolites. The volcano-plutonic association was formed in the supra-subduction settings, as is evidenced by the composition of the rocks.

Sayan–Biryusa Volcanoplutonic Belt (Southern Siberian Craton): Age and Petrogenesis

Abstract —Geological, geochronological, and geochemical isotope studies are carried out for metamorphosed volcanic rocks and dolerites of the Maltsevka sequence of the Elash Group in the Biryusa block of the Siberian craton. It is found that mafic igneous rocks (dolerites and basaltic andesites) are close in composition to intraplate basalts. Flat or slightly fractionated REE patterns ((La/Yb)n = 1.3–2.3) and positive εNd(T) values of +3.7 and +4.1 are observed. It is assumed that the depleted asthenospheric mantle and, possibly, plume mantle were the sources of these rocks, while the lithospheric mantle had no significant effect. Meta-andesites of the Maltsevka sequence belong to the tholeiitic series and have high La, Th, and U contents. Pronounced negative Nb and Ti anomalies are observed in the multielement patterns of these rocks, along with negative εNd(T) values of –4.6. It is assumed that meta-andesites were resulted from the late Archean crustal melting with the participation of the mantle material. Metarhyolites prevalent in the Maltsevka sequence are divided into two groups similar in REE composition to A-type and I-type granites. A-type metarhyolites show high contents of Zr, Y, Nb, Th, and REE (except for Eu) and positive εNd(T) values of +2.2 and might have resulted from the melting of the source with geochemical isotope parameters close to those of mafic igneous rocks of the Maltsevka sequence. I-type metarhyolites have low contents of Y, Yb, Zr, and Nb but high contents of Th and show negative εNd(T) values of –3.7. They might have resulted from the melting of lower crustal diorite–tonalite rocks with addition of juvenile mantle material to the magma generation area. U–Pb zircon dating of metarhyolites of the Maltsevka sequence corresponding to A- and I-type granites showed that they are close in age, 1872 ± 10 and 1874 ± 10 Ma, respectively, which agrees with the age estimated earlier for granitoids of the Sayan complex of the Biryusa block. The similar ages and structural positions, along with the localization within the same structure, made it possible to unite volcanic rocks of the Elash Group and granitoids of the Sayan complex of the Biryusa block into a Paleoproterozoic volcanoplutonic association. The rocks of the association form the Sayan–Biryusa volcanoplutonic belt stretching for about 300 km along the zone of junction of the Biryusa block of the Angara fold belt and the Archean Tunguska superterrane of the Siberian craton. The belt is part of the large Paleoproterozoic South Siberian postcollisional magmatic belt formed at the final formation stage of the Siberian craton, when it was possibly part of the Paleoproterozoic Columbia supercontinent.

Orosirian magmatic episodes in the erepecuru-trombetas domain (southeastern Guyana shield): Implications for the crustal evolution of the Amazonian craton

The granitic rocks of the Erepecuru-Trombetas Domain, southeastern Guyana Shield, are part of two extensive volcano-plutonic associations that marked the central portion of the Amazonian Craton during the Orosirian. The older episode (2.0–1.97 Ga) encompasses the Igarapé Paboca volcanic Formation and Caxipacoré Suite and the younger episode (1.90–1.87 Ga) comprises the Água Branca and Mapuera plutonic suites and the pyroclastic/effusive rocks of the Iricoumé Group. LA-ICP-MS U-Pb zircon dating of granitoids provided ages of 1991 ± 5.9 and 1989 ± 7 Ma for the Caxipacoré Suite, 1887.5 ± 4.8 Ma for the Água Branca Suite and 1881 ± 8.1 Ma for the Mapuera Suite, which reinforce the occurrence of two Orosirian magmatic episodes in the southeastern Guyana Shield. The geochemical characteristics of the Caxipacoré granitoids suggest that they formed in an orogenic tectonic setting, related to a subduction environment, while the geochemical signatures of the Água Branca and Mapuera granitoids betray the evolution from a convergent context to an extensional intracontinental environment. Nd-TDM (2.19–2.22 Ga) and Sr-TUR (1.95–1.96 Ga) model ages and slightly positive εNd (+0.26 to +0.66) for the Caxipacoré granitoids point to an origin from melting of mantle-derived magmas with participation of Rhyacian sialic crust. The Água Branca and Mapuera granitoids display Nd-TDM (1.95–2.30 Ga) and Sr-TUR (1.84–2.02 Ga) model ages and positive to negative εNd (+2.92 to −1.96) that indicate parental magmas derived from melting of dominantly Rhyacian crustal sources with minor mantle contribution. In addition, the Nd signature and the lack of Archean inherited zircon in the plutonic rocks do not favor the existence of an Archean basement in this part of the southern Guyana Shield. This assumption together with similarities with the adjacent Uatumã-Anauá Orosirian Domain, westward, led to suggest that the Erepecuru-Trombetas Domain should not be longer interpreted as belonging to the Central Amazon Province, as defined in the current geotectonic models of the Amazonian Craton.

Pirin metamorphic and igneous evolution revisited in a geochronological frame based on U-Pb zircon studies

New isotopic data obtained from zircons by the U-Pb method during the last decade show the necessity of a revision of the tectonometamorphic and igneous evolution of the Pirin–Pangaion Unit of the Alpine Morava–Rhodope tectonic zone. The northern (Pirin) subunit of this unit consists of four areas built up of metamorphic rocks (amphibolite facies) of the Rhodopian supercomplex. These areas are separated by Late Alpine granite plutons of batholithic dimensions. The northernmost (Krupnik) area is built up of rocks of the Rupchos Group (complex) of varied composition and intense multiphase deformation and metamorphism. The oldest metamorphic phase is dated as Cadomian (528–517 Ma), and its products also suffered Hercynian superimposed amphibolite-facies metamorphism and anatexis. A septum of granitised metamorphics preserved between the Krupnik granite pluton (Triassic, ca 240 Ma) and the early Oligocene North Pirin (Kresna) pluton is characterised by Hercynian (330–300 Ma) anatexis. The principal metamorphism within the southern area around the early Oligocene South Pirin (Teshovo) granite pluton is dated both in the Bachkovo quartzo-feldspathic gneisses (named also Kriva-reka metagranites or orthogneisses) and in the Lukovitsa schists and paragneisses as Hercynian (ca 300–290 Ma). Therefore, the polymetamorphic evolution of the Pirin Subunit consists of a Cadomian phase and a strong Hercynian overprint followed by Triassic granitoids. We confirm the Thanetian–early Eocene age (58–55 Ma) of the Spanchevo granite, partially formed by in situ anatexis. Its intrusion was followed by a compression phase during the mid-Eocene thrusting of the Ograzhden Unit over the Pirin–Pangaion Unit, along the Strimon Thrust. The last magmatic phase (ca 34–31 Ma) was represented by a granitoid association formed during the latest Eocene–early Oligocene in extensional conditions and as a result of mixing of anatectic crust-derived magma with magma of mantle origin. It was part of a volcano-plutonic association related to the Macedonian–Rhodope magmatotectonic province. A high-temperature metamorphic overprint of the same age is recorded in the metamorphics as formation of andalusite in the metapelites, and skarns at the contacts of some of the granitoid bodies.

Shoshonite-latite series of the Eastern Transbaikalia: 40Ar/39Ar age, geochemistry, and Sr-Nd isotope composition of rocks from the Akatui volcano-plutonic association of the Aleksandrovskii Zavod depression

The paper presents new data on age, geochemistry, and Sr and Nd isotope composition of rocks from the Akatui massif and comagmatic rocks from the lower unit of the Kailas Formation (Akatui volcano-plutonic association), localized within the Aleksandrovskii Zavod depression. The amphibole 40Ar/39Ar age date the monzogabbro of the early phase of the Akatui massif at 154.8 ± 4.4 Ma; the monzonite of the main phase yields a 40Ar/39Ar age of 160.7 ± 3.9 Ma, and the shoshonite basalt of the lower unit of the Kailas Formation yields a 40Ar/39Ar age of 161.5 ± 1.7 Ma. The leading petrogenetic mechanism for the Akatui volcano-plutonic association is crystal fractional differentiation of melts with minor crustal contamination, which can be suggested from the mineralogical and petrographic features and geochemical and isotope characteristics of rocks. The geochemical data for the Akatui volcano-plutonic association show LILE, LREE, U, Th, and Pb enrichment with a characteristic depletion in high-field strength elements (HFSE), such as Nb and Ti. They are also depleted in P. Sr-Nd isotope data (87Sr/86Sr(160 Ma) = 0.70642-0.70688 and £Nd(160 Ma) = −0.6 to −2.2) suggest an EMII-type mantle source and could also indicate a negligible degree of crustal contamination in the evolved melts.

Inglés

New field data, geochemical analyses and zircon U-Pb LA-ICP MS data were obtained on plutonic and volcanic rocks of the Mocoa Batholith and Saldana Formation in southern Colombia Putumayo region. Results suggest that the plutonic and volcanic activities are closely related to a common magmatic history. This volcano-plutonic association presents a well-defined LILE and LREE enrichment and negative Nb and Ti negative anomalies characteristic of continental magmatic arcs. Volcanic and plutonic rocks crystallized between 180-186 Ma as revealed by U-Pb zircon geochronology. The magmatic activity is temporally and chemically correlatable with other magmatic arc exposures in Colombia and Ecuador. These units may represent the remnants of a single belt which includes several units from 4°N in Colombia and 5°S in Ecuador. This arc is related to the widespread Jurassic continental magmatic arc setting that characterized the continental margins of the Americas after Pangea break-up.

Neoproterozic anorogenic rhyolite-granite volcanoplutonic association of the Aktau-Mointy sialic massif (Central Kazakhstan): Age, source, and paleotectonic position

Rhyolite-granite volcanoplutonic association was identified among the Precambrian basement complexes of the Aktau-Mointy Massif, Central Kazakhstan. This association comprises rhyodacites, rhyolites, subalkaline rhyolites, tuffs, and felsic volcanogenic-sedimentary rocks of the Altyn Syngan and Urkendeu formations, as well as granitoids of the Uzunzhal Complex. U-Pb (ID-TIMS) dating of accessory zircons from the volcanic rocks and granites showed that the association was formed in the Neoproterozoic (Tonian, 925–917 Ma). The Neoproterozoic volcanic rocks and granites are the youngest Precambrian magmatic complexes and mark the final stage in the formation of the Precambrian crust of the Aktau-Mointy Massif. In terms of major and trace element composition, the volcanic rocks and granites resemble A-type granites, thus indicating the within-plate settings of their formation. It was established that their primary magma could be derived by melting of metatonalitic or metagraywacke protolith at T ≥ 940°C and P ∼ 8–10 kbar in response to mantle magma underplating. Sm-Nd isotope data on the volcanic rocks and granites (TNd(DM) = 1.9−1.7 Ma, ɛNd(T) from −1.9 to −3.5) testify the Paleoproterozoic age of their crustal protolith. Available data have revealed strong similarity between the Neoproterozoic tectonomagmatic evolution of the Aktau-Mointy Massif and the Congo-Sao Francisco paleocontinent, which, with other cratons, composed the southern Rodinia supercontinent. This suggests that the formation of the Tonian anorogenic volcanoplutonic association of the Aktau-Mointy sialic massif was related to the global-scale divergent processes in the southern Rodinia supercontinent (Congo-Sao Francisco paleocontinent).