To carry out U-Pb isotope dating of relict zircons, 31 grains were isolated from a composite sample of restitogenic ultramafic rocks of the Shaman massif ( Eastern Transbaikalia) weighing about 4 kg. All of them were characterized by a rounded shape, rough surface and micro-fracturing, a very low intensity of cathodoluminescent glow up to its complete absence, disturbed oscillatory zoning, as well as very wide variations in the isotopic age (3050- 502 Ma). The study of the entire collection of zircons by the electron probe method showed that 20 of them contain suitable size (from the first microns to 10 mu m, in some cases - up to 100 mu m) for the analysis by this method of morphologically different microinclusions of minerals that are not characteristic of ultramafic restites (rel. %): quartz (52.3), mica (15.2), chlorite (13), calcite (6.6), plagioclase (andesine) (4.3), rutile (4.3), xenotime (4.3). The chemical composition of minerals from microinclusions and their phase composition were studied based on the results of 68 analyzes performed by the above method. Quartz microinclusions were predominantly irregular, sub-isometric, or vein-like; segregations of other minerals sometimes had crystallographic faceting. Some microimputiries of quartz were in the form of linear-streaky accumulations or epitaxic intergrowths located on the rounded surface of zircon grains. Microinclusions were located both in the inner and outer zones of the zircon grains. Studies of the composition and properties of minerals from microimputiries allowed us to conclude that they are of epigenetic nature. Their formation was due to the infiltration of fluids released by later granitoid melts. Fluids introduced into ultramafic rocks and relict zircons in them, both some mineral-forming elements and trace elements, such as REE, U, Th and others, which were deposited in microimputiries and other deformation defects of zircon grains. The uneven distribution of these impurities has led to the geochemical heterogeneity of zircons. The U introduced in this case caused the disturbance of its initial balance with the radiogenic Pb isotopes in zircons, which is supposed to be one of the reasons for the observed wide variations in the values of their isotopic age.

The article presents the results of 30 determinations of isotopic age in 18 zircon grains performed by the LA-SF-ICP-MS method from four bulk samples of olivine gabbronorite (K-1, K-2), olivine gabbro (K-5) and plagioverlite (K-7) selected in the central part of the Kalbakdag mafic-ultramafic massif, which was previously considered as a typical layered intrusion. This massif is located in the central part of the territory of Tuva within the Ondum island-arc subzone of the Early Caledonids and breaks through the metavulcanogenic-terrigenous strata of the Late Neoproterozoic - Lower Cambrian. The rocks of the massif are characterized by moderate magnesium content, low alkali content, very low titanium and phosphorus content. The content of rare earth elements in them is lower than NMORB at (La/Yb)n = 0.52-1.71, positive anomalies of K, Sr, Zr, Hf, Eu of low intensity and negative anomalies of Nb and Ta are noted on spiderograms. The dated zircons, in addition to differences in morphological and optical properties, are characterized by significant variations in isotopic age, that is, they are polychronous. The entire collection of dated zircons is conditionally divided into four "populations" (clusters): Neoarchean-Paleoproterozoic (2747-1862 Ma, zircons from samples K-2 and K-5), Neoproterozoic (799-648 Ma, zircons from samples K-1 and K-5); Cambrian-Devonian (525-383 Ma, zircons from samples K-2 and K-7) and Carbonian-Permian (325-279 Ma, zircons from sample K-5). Zircons from the first and second "populations" are proposed to be considered as a xenogenic phase introduced into the parent melts of the gabbroids of the Upper Mantle protolith massif. They are to varying degrees "rejuvenated" very ancient juvenile zircons that were previously present in this protolith and preserved in ultramafic restites formed on it. In turn, zircons from the Cambrian-Devonian "population" are proposed to be considered as a syngenetic phase, the age of which corresponds to the time of formation of gabbroids of this array. The concordant age of syngenetic zircons was 477 +/- 5 Ma. Zircons from the Permian "population" have been identified as an epigenetic phase formed during infiltration into rocks of an array of fluids separated from late granitoid melts. According to the totality of available data, the Kalbakdag massif is considered by us as a polygenic association of spatially converged fragments of earlier protrusion of hybridized restitogenic ultramafites (plagioverlites and pyroxenites) and mesoabyssal gabbroid intrusive (olivine and non-olivine gabbro and gabbronorites) introduced in the Early Paleozoic.

Research subject. The distribution patterns of rare earth elements (REE), as well as Y and Th, in the grains of polychromous zircons from the restitogenic ultramafic rocks of the Shaman massif (Eastern Transbaikalia). This massif is a steeply inclined protrusion that is part of the eastern branch of the Baikal-Muya ophiolite belt.Materials and methods. 31 zircon grains 100–150 μm in size were isolated from a composite sample of harzburgites and dunites with a total weight of 4 kg for their subsequent U-Pb isotope dating. These analyzes were performed by the LA-ICP-MS method by scanning along straight profiles on the plane of sections of representative zircon grains.Results. All zircon grains from the general collection are characterized by a rounded shape, a rough surface, microfracturing, a weak cathodoluminescent glow to a complete absence, and an irregular oscillatory zoning. In some grains, microinclusions of epigenetic minerals, such as quartz, mica, etc. were found. It was previously determined that, within the entire collection of zircon grains, the values of their age, as well as U and Th contents, vary across rather wide intervals (3049–502 Ma), the reasons for which are the subject of discussions. The LA-ICP-MS scanning over the profiles of representative zircon grains from the general collection showed that REE, Th, and Y are distributed highly unevenly, occasionally showing signs of zoning. It is assumed that the zircons found in the ultramafic rocks of this massif are a relict phase and appeared as a result of the transformation of very ancient (more than 3 billion years old) juvenile crystals of this mineral, which had been originally located in the upper mantle protolith.Conclusions. Transformations of juvenile zircons and their transformation into a relict phase occurred in the process of partial melting of the protolith, during which they underwent thermal action (annealing), chemical resorption, as well as disturbances in their U-Pb systems, which caused uneven “rejuvenation” of their isotopic age. It is also assumed that the revealed geochemical heterogeneity of relict zircons was mainly due to the later redistribution of trace elements with the simultaneous formation of microinclusions of epigenetic minerals in the process of infiltration along microcracks into ultramafic rocks, precipitated by acidic melts.

For the first time, for the territory of Tuva, relict and epigenetic zircons from restitogenic harzburgites and chromitites of the Agardag chromite-bearing ultramafic massif were discovered and sold by U-Pb by the isotope method. An array located in the southeastern part of Tuva near Lake Shara-Nur, located on the southwestern flank of the ophiolite South Tuva mafic-ultramafic area. The lens-shaped body of the massif has a length of about 20 km with a maximum width of 4 km. Its long axis is oriented in a northeast direction. The massif has steep (75-80 degrees in NW) tectonic contacts with host metaterrigenous-volcanic Riphean-Lower Cambrian (?) Formations and is considered by us as a protrusion. The massif is composed to varying degrees with serpentinized harzburgites and dunites, as well as antigorite and more rare antigorite-chrysotile serpentinites. In the near-contact zones of the massif, serpentinites are intensively schistose. The massif is intruded with gabbro rods, gabbro-diorites, gabbro-diabases, diabase and basalt porphyrites stocks and dikes. Zircons isolated from large-sized (similar to 20 kg) samples of harzburgites and chromitites are represented by relict and epigenetic genetic varieties. Their short-prismatic crystals sometimes have rounded edges due to resorption, a relatively low intensity of the cathodoluminescent glow to its complete absence, and also often disturbed oscillatory zoning. The sub-concordant and concordant values of the U-Pb isotope age of relict zircons range from 885-392 Ma. It is assumed that these age variations are associated with a partial diffusion loss of radiogenic lead, which caused the uneven "rejuvenation" of the U-Pb isotopic systems of very ancient juvenile zircons located in the upper mantle protolite during its partial melting with the formation of harzburgite and dunite restites, as well as chromite deposits associated with them. The observed close values of the isotopic age of zircons from harzburgites and from chromitites suggest that both formed approximately at the same time. A few zircon grains from harzburgites, which showed concordant age values in the range of 293-276 Ma, are considered by us as an epigenetic phase. Their formation, as expected, was caused by the infiltration of fluids, which were released by melts, which formed later granitoid intrusions, cutting the ultramafic massif, and also framing it with metaterigenic-volcanogenic formations. Evidence of the infiltration of such fluids is found in the chromitites of the mass of Uvarovite - Kemmerite veins, the formation of which requires the addition of silica.

The work presents the results of a study on Lu-Hf systematization of zircons from rocks of the Shamanic ultramafic massif, which is part of the Baikal-Muya ophiolite belt. It is composed to varying degrees of serpentinized and dynamometamorphized harzburgites and dunites subordinate to them, which have a restitogenic nature. From a composite sample of these rocks weighing about 4 kg, 31 zircon grains 100-150 mu m in size were extracted and sold by U-Pb. All these grains had a rounded shape and a rough surface. Most of them are characterized by a very low to complete absence of cathodoluminescent light intensity. According to the values of the isotopic age, the entire collection of zircons was divided into three clusters: a) "ancient" (3,049-1,189 Ma); b) "intermediate" (827-812 Ma); c) "young" (630-502 Ma). In representative mineral grains from these clusters, the parameters of their Lu-Hf isotopic systems were determined. Zircons from the "ancient" cluster are characterized by increased values of the parameter (PbPb)-Pb-207-Pb-/ 206, as well as lower values of the parameters Th-232/U-238, Yb-176/Hf-177, Lu-176/Hf-177 and Hf-176/Hf-17(7). Zircons from the "intermediate" cluster are characterized by increased values of the parameter Th-232/U-238, lower values of the parameter Yb-176/Hf-177, as well as intermediate values of the parameters Lu-176/Hf-177 and Hf-176/Hf-177. Zircons from the "young" cluster are characterized by intermediate values of the parameter 232Th/ 238U, approximately the same as in the previous cluster, by the values of the parameter Yb-176/Hf-177, and also by increased average values of the parameters Lu-176/Hf-177 and Hf-176/Hf-177. The studied zircons are considered as a relic phase. It is assumed that initially the few grains of this mineral were in the form of a juvenile phase in the composition of the upper mantle protolith, whose age exceeded 3,000 million years. It is also assumed that subsequently, during the heating and partial melting of protolith, which initiated the diffusion of Pb and U ions in the structure of juvenile zircons, disturbances occurred in their U-Pb and Lu-Hf isotopic systems, which caused the observed uneven "rejuvenation" of their age.

—We present the first data on the geochemistry and isotopic age of zircons from rocks of the Roseta (lherzolite and olivine orthopyroxenite) and Córrego da Areia (olivine orthopyroxenite) ultramafic massifs localized among Archean–Proterozoic metamorphic strata in the southern folded framing of the São Francisco Craton. The examined zircons differ in crystal morphology, the intensity and type of cathodoluminescence, oscillatory zoning, the distribution of trace elements, and U–Pb isotopic age. Zircon crystals from the Roseta lherzolite have an age of 800-728 Ma and show negligible cathodoluminescence. Some of them have reaction rims with an age of 663–619 Ma. The crystal cores are enriched in rare earth elements (REE) but are often depleted in U as compared with the reaction rims. The age of zircons from the Roseta olivine orthopyroxenite showing moderate cathodoluminescence is within 622.6–596.9 Ma. Zircons from the Córrego da Areia olivine orthopyroxenite show moderate to intense cathodoluminescence and often have a rhythmic oscillatory zoning. They are characterized by an uneven distribution of REE and other trace elements and have high contents of U and Th. Most of these zircons have an ancient isotopic age (2558–2100 Ma). The examined zircons are of several types: relict, xenogenic, syngenetic, and epigenetic. The Roseta and Córrego da Areia massifs are considered to be protrusive outliers of a deep-seated Precambrian mafic–ultramafic complex, which were tectonically transferred along faults into the intensely metamorphosed Archean–Proterozoic strata in the southern folded framing of the São Francisco Craton.

A systematic investigation of amphibolites and a metaultramafite granofels was carried out in the southernmost Brasilia Orogen, part of the reworked margin of the Sao Francisco paleocontinent. These rocks occur interleaved within Neoproterozoic metasediments and the Archean-Paleoproterozoic basement. The amphibolites from the Andrelandia, Liberdade and the Carrancas nappe system show an N-MORB signature, enriched to slightly depleted in LILE (Large Ion Lithophile Elements) and LREE (Light Rare Earth Elements) and depletion in the HFSE. They define a flat sub primitive mantle (PM) normalized curve with negative anomalies of Nb and Ce. The Lima Duarte nappe amphibolite has an andesitic basalt with an E-MORB signature and magmatic arc filiation. U-Pb (SHRIMP) zircon dating on the different samples yielded similar crystallization ages of ca. 2.15 Ga. Metamorphic conditions record amphibolitic facies for all the samples and can be linked to lower intercepts aged between 560 and 590 Ma. Whole rock Nd isotopic data suggest a juvenile source with TOM ages between 1.95 and 2.22 Ga. The associated metaultramafite, from Carrancas Klippe, highlights inherited cryptic layering and fractional crystallization processes from mineral and whole rock chemistry. It is enriched in LILE and shows negative anomalies of Th and Nb and positive anomalies of Sr and Zr. The Platinum group elements present a total PGE abundance of 16.5 and 30.8 ppb. The Iridium group defines a steep positive normalized curve while the Palladium group defines a gentle positive one, as expected for differentiated liquids. U-Pb zircon dating yielded three data clusters: i) the ca. 2.5 Ga, interpreted as inheritance, ii) the ca. 2.1 Ga, considered as the crystallization age and, iii) the youngest, being ca. 600 Ma, associated with the amphibolite facies metamorphic overprint. REE analyses on Rhyacian zircons suggest plagioclase crystallization under the influence of free-REE bearing minerals. A magmatic zircon grain containing a quartz inclusion, presents a distinctive REE pattern, with a positive normalized curve and a strong negative Eu anomaly. It suggests a hybridized crystallization under influence of plagioclase-rich and silica-saturated fluids prior or during the igneous crystallization, possibly due to the influence of slab derived materials. These data unravel new insights towards mafic-ultramafic rocks formation in different settings within a Rhyacian suprasubduction system in the southernmost part of the Sao Francisco paleocontinent, later reworked during the Gondwana amalgamation.

Presents the results of detailed studies of the chemical composition of the main (olivine, orthopyroxene, clinopyroxene, plagioclase and amphibole) and secondary (scapolite, magnetite, ilmenite) minerals of channel samples of olivine gabbronorite Callbackmessage array. The gabbroids of this massif crystallized, probably, during the upward motion of the mafic melt, which was a structured suspension. The latter consisted of mixing and acquiring a wavy arrangement of phenocrysts of olivine, orthopyroxene, clinopyroxene, and plagioclase immersed in the bulk, consisting of subparallel oriented long axis and "streamlined" porphyritic phenocrysts of plagioclase laths and because of this, with trachytoid texture. The result of mixing porphyroid inclusions in the process of upward movement of the melt-suspension was that in being in close proximity to each other pyroxene inclusions evidence of their chemical equilibrium, that is, the consistency of their compositions. Banded texture gabbroids Callbackmessage array are likely the result of late-magmatic processes that are not associated with intra crystallization-gravitational differentiation of mafic melt.

The data on the chemical composition of microinclusions in zircon grains from rocks of the polygenic Berezovskii mafic-ultramafic massif (Sakhalin Island), obtained using the JEOL JXA-8100 electron probe microanalyzer, is presented. In the massif structure has a protrusion of restitogenic ultramafic rokcs, intruding its intrusion of ortomagmatic gabbros, and the two contact-reaction zones along with contact of gabbroid intrusion with ultramafic protrusion (hybrid olivine gabbro and ultramafic), and with enclosing strata (hybrid quartz-bearing gabbros and diorite). Zircons are divided into four varieties: relict, xenogenic, syngenetic, and epigenetic. Microinclusions with an apparent size of 10-20 mu m were found mainly in syngenetic zircon grains from hybrid gabbro-diorites, diorites, and quartz diorites. They are represented by more common carbonate and K-Na feldspars, as well as more rare quartz, albite, mica and unidentified phases. In isolated cases, the microinclusions of grossular, siderite and iron oxide were encountered. Microinclusions did not occur in zircon grains from ultramafic and olivine gabbroids, for which the determinations showed an ancient U-Pb isotopic age.

Mafic-ultramafic massifs of Tuva territories are located both within linear belts tracing deep faults and as "disordered" areas associated with some belts sufferedthe later fold-block dislocations. Sometimes fragments of mafic-ultramafic bodies are present in granitoidal intrusive asxenogenic blocks of various sizes. Areal location of ultramafic massifs is particularly observed in the east of Tuva within the Khamsarynsky structural-formation zone as well as in the structures of the Tuvinian-Mongolian middle massif. Geochemical features of the ultramafic massi frock variety studies are continued for obtaining convincing conclusions on their formational affiliation. Ultramafic massifs of Tuva have isolated single data in terms of the geochemical characteristics which requires a purposeful work in this direction. The present paper summarizes for the first time petro-geochemical characteristics of dunites of the Nizhnetarlashkynsky ultramafic massif and fragments of individual picritic dikes among them.

The results of isotope U–Pb dating of zircons from lherzolite and vein olivine orthopyroxenite composing the Roseta ultramafic massif are presented. The zircons differ in their morphological, optical, and geochemical properties and in their age. Lherzolite samples that are almost deprived of cathodoluminescence are represented by two age clusters 788 ± 15 and 638.2 ± 5.4 Ma. The zircons from the first cluster are relict. A later event recorded in the zircons from the second cluster was manifested in an intense metamict mineral transformation. The age of the zircons from vein olivine orthopyroxenite conforms to 608.9 ± 3.4 Ma. These zircons are considered to be syngenetic; therefore, their age is determined by the time of crystallization of olivine orthopyroxenites.

The paper presents the results from a study of original and published data on the chemical composition and age of mantle peridotites from Sakhalin Island ophiolites. The material and genetic proximity of peridotites from the Berezovsky and Shelting plutons, on the one hand, and mélange zone serpentinites, on the other, have been established. In composition and Fe2O3 and MgO variations, Sakhalin peridotites differ radically from those of the Northeast Asia ophiolite complexes (Krasnogorsky Massif, Karaginsky Island Massif, etc.), which are fragments of Pacific Plate mantle. Conversely, Sakhalin peridotites have a subcontinental genesis and are compositionally close to xenoliths of lherzolites from Hankai Microcontinent mantle (southern Sikhote-Alin). The rythmics of alternation in compression and expansion at the margin of the Asian continent in the last 180 million years, caused by cyclical changes in the Pacific spreading rate, have been considered. According to data obtained by U-Pb dating of zircons, the formation of the Berezovsky Massif took place 169–154 Ma ago during Jurassic expansion of the continental margin. Matching age and composition data demonstrate that the Sakhalin ophiolites formed within the marginal sea basin during riftinduced destruction of the periphery of the Hankai Craton. The assumed tectonic setting was close to that reconstructed for the Jurassic Josephine ophiolites of the California margin of the North American continent. The continental genesis of the studied ophiolites agrees with the age and tectonic mode of ophiolite formation for Sakhalin Island.

The research on petrochemistry and geochemistry of rare, rare earth and platinum group elements in the rocks Shaman massif - the largest ultramafic protrusion body in eastern branch of the Baikal-Muya ophiolite belt, performed using a different of analytical techniques (X-ray fluorescence analysis, mass spectrometry analysis with inductively coupled plasma and laser ablation; synchrotron radiation method). Harzburgites and subordinate dunites, composing massif, depleted TiO2, Na2O, K2O and CaO, and rare earth elements (REE). The total content of the latter in harzburgites somewhat higher (0.29-3.01 ppm) than in dunites (0.12-1.54 ppm). The patterns of chondrite-normalized REE contents in ultramafic rocks are arched downward configuration, due to their abnormal enrichment nonstructural admixture of light elements, centered as it is assumed in the intergranular and within granular microcracks. Massif is characterized by higher contents of Zr and Hf, the hub of which is supposed to be an accessory zircon. The total content of platinum group elements (PGE) in the harzburgite and dunite are from 12.50 to 24.35 ppb, while the predominant element is Ru. There was an inverse relationship between its content and the content of heavy rare earth elements (Er, Tm, Yb, Lu), and between the total content of PGE and REE, which are supposed to be due to divers directional fractionation of these groups of elements with contrasting properties in the process of partial melting of upper mantle protolithe. Prevalence of Ru in the rocks suggested that PGE concentrated mainly in the such minerals as rutenosmirid and laurite.

The olivine shonkinites localized among dunites and alkali gabbroids in the northern part of the alkaline ultrabasic Inagli massif (northwestern part of Central Aldan) have been studied. The obtained data on the chemical and trace-element compositions of the rocks and minerals and the results of melt inclusion study showed that the olivine shonkinites crystallized from alkaline basanite melt enriched in Cl, S, CO2, and trace elements. Clinopyroxene crystallized at 1180-1200 degrees C from a homogeneous silicate-salt melt, which was probably separated into immiscible silicate and carbonate-salt fractions with temperature decreasing. The composition of the silicate fraction evolved from alkaline basanite to alkaline trachyte. The carbonate-salt fraction had an alkaline carbonate composition and was enriched in S and Cl. The same trend of evolution of clinopyroxene-hosted melts and the igneous rocks of the Inagli massif suggests that the alkali gabbroids, melanocratic alkali syenites, and pulaskites formed from the same magma, which had a near-alkaline basanite composition during its crystallization differentiation. The geochemical studies showed that the olivine shonkinites and glasses of homogenized melt inclusions in clinopyroxene grains have similar contents of trace elements, one or two orders of magnitude higher than those in the primitive mantle. The high contents of LILE (K, Rb, and Sr) and LREE in the olivine shoshonites and homogenized inclusions suggest the enriched mantle source, and the negative anomalies of HFSE and Ti are a specific feature of igneous rocks formed with the participation of crustal material. The slight depletion in HREE relative to LREE and the high (La/Yb)(n) ratios in the rocks and inclusion glasses (10.0-11.4 and 4.7-6.2, respectively) suggest the presence of garnet in the mantle source. (C) 2016, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.

Results of comprehensive isotope-geochronological (U-Pb dating; SHRIMP II) and geochemical (LA-ICP-MS) studies of zircons from different rocks of the Berezovka polygenetic mafic-ultramafic massif of the East Sakhalin ophiolite association are presented. The massif includes three proximal but genetically autonomous structure-lithologic complexes of different ages: protrusion of ultramafic rocks of restite nature, gabbroid intrusion breaking through it, and contact reaction zone located along their boundaries. The isotopic age of zircons in the massif as a whole and in its individual rocks varies over a broad range of values. The zircons belong to several populations according to their age (Ma) and other features: relict and xenogenous (similar to 3100-990, 70-410, and similar to 395-210) and syngenetic (similar to 200-100, similar to 90-65, and similar to 30-20). They differ in grain size and morphology, optical and cathodoluminescence images, and trace-element patterns. By morphology, the grains are divided into short-prismatic crystals with well-developed faces and edges, long-prismatic crystals with well-developed faces and edges, prismatic crystals with slightly resorbed faces and edges, prismatic crystals with strongly resorbed faces and edges, and intensely resorbed grains totally or partly lacking faceting. The ages of zircons depend inversely on the contents of La, Ce, and Yb, total contents of REE, (Ce/Ce*)(n), and (Eu/Eu*)(n). Some grains are characterized by abnormal REE and trace-element patterns due to their epigenetic redistribution. The wide scatter of the intermediate ages of relict and xenogenous zircon grains, their resorption and disturbed optical and geochemical features are probably due to the nonuniform rejuvenation of their isotope systems and variations in other parameters, caused by the effect of younger mafic melt and its fluids, whose crystallization gave rise to a gabbroid intrusion dated at 170-150 Ma. The obtained data on the isotopic age and other properties of zircons from the rocks of the Berezovka massif agree with the geological model of its polygenesis. (C) 2015, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.

This paper summarizes analytical data accumulated in the world literature and other materials about the regularities of the REE distribution in minerals contained in ultramafic and mafic rocks as accessory phases. These minerals are tentatively divided into two groups. The first includes garnets, zircons, apatites and perovskites, which can accumulate increased amounts of REE in their structure. The second consists of minerals whose structure can accumulate only limited contents of these trace elements. These are chrome-spinels, ilmenites, and micas. These minerals, in respect of REE geochemistry, are studied to a varying degree because of the different levels of accumulations of these elements, different degrees of occurrence in rocks, tiny sizes of their grains and other reasons. The analytical database formed on their basis includes about 600 original analyses. The overwhelming majority of presently available data on REE geochemistry in accessory minerals from ultramafic and mafic rocks have been published only in the recent 15 years. The studies became possible due to the development and introduction of new highly sensible microprobe analyses allowing detection of REE and many other trace elements in minerals grains directly in thin sections. The greatest numbers of these analyses were performed for garnets and zircons, fewer for apatites, and the fewest for chrome-spinels, ilmenites, micas, and perovskites. In general, the regularities of REE distribution in these minerals from ultramafic and mafic rocks are less studied compared to the rock-forming minerals from ultramafic and mafic rocks. Among the analytical methods, which were used to study the REE composition of accessory minerals, the most efficient was the mass-spectrometry with inductively coupled plasma (ICP-MS).