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Acta Geologica Sinica(English Edition) 2024年第1期98卷 67-82页

作者： Nadezhda KANYGINA Andrey TRETYAKOV Dmitriy ALEXEIEV Kirill DEGTYAREV Anfisa SKOBLENKO Natalia SOLOSHENKO Boris ERMOLAEV Geological institute Russian Academy of SciencesMoscow 119017Russia A.N.Zavaritsky institute of geology and Geochemistry Ural Branch of the Russian Academy of SciencesYekaterinburg 620016Russia

The combined petrographic,petrological,geochemical and geochronological study of the Neoproterozoic gneisses of the Sarychabyn and Baskan complexes of the Junggar Alataw of South Kazakhstan elucidate the precambrian tectonic evolution of the Aktau–Yili *** is one of the largest precambrian crustal blocks in the western Central Asian orogenic *** U-Pb single-grain zircon ages indicate that granite-gneisses formed from the same source and crystallised in the early Neoproterozoic ca.930–920 *** chemical composition of gneisses corresponds to A2-type *** whole-rock Nd isotopic characteristics(εNd(t)=−4.9 to−1.0 and TNd(DM-2st)=1.9 to 1.7 Ga)indicate the involvement of Paleoproterozoic crustal rocks in magma *** Neoproterozoic ca.930–920 Ma A-type granitoids in the Aktau–Yili terrane of South and Central Kazakhstan might reflect within-plate magmatism adjacent to the collisional belt or a local extension setting in back-arc areas of the continental arc.

关键词： granitoid magmatism geochemistry geochronology Sm-Nd isotope systematics Neoproterozoic Junggar Alataw Kazakhstan Central Asian orogenic belt

Zircon Xenocrysts from the Shaka Ridge Record Ancient Continental Crust:New U-Pb Geochronological and Oxygen Isotopic Data

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Journal of Earth Science 2022年第1期33卷 5-16页

作者： Sergey G.Skublov Natalia A.Rumyantseva Qiuli Li Boris G.Vanshtein Dmitriy I.Rezvukhin Xianhua Li institute of precambrian geology and geochronology of russian academy of sciences St.Petersburg 199034Russia Saint Petersburg Mining University St.Petersburg 199106Russia institute for geology and Mineral Resources of the World Ocean(VNIIOkeangeologia) St.Petersburg 190121Russia State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Sobolev institute of geology and Mineralogy Siberian Branch of the Russian Academy of SciencesNovosibirsk 630090Russia

Over the past two decades, a significant number of discoveries of ancient zircon xenocrysts in ocean-floor magmatic rocks have been reported. These findings provide compelling evidence for the presence of ancient continental crust within young oceanic lithosphere. Almost all finds of ancient zircon xenocrysts within oceanic crust are from the Mid-Atlantic Ridge. For other localities, however, similar data are very limited. This report presents the first age determinations(U-Pb, SHRIMPII) and isotope-geochemical data(oxygen, trace and rare earth elements) for zircon xenocrysts from gabbro-diorites of the Shaka Ridge, in the vicinity of the Shaka fracture zone, near the western end of the Southwest Indian Ridge. The work is based on a study of bottom rock material dredged during expeditionary research on the R/V"Akademik Fedorov"(Russia) in 2016. The U-Pb isotope system of the zircon xenocrysts recorded a crystallization age of ~2.8 Ga at an upper discordia intercept and an age of ~600 Ma interpreted as the timing of a superimposed thermal event at a lower discordia *** zircon xenocrysts show geochemical signatures of magmatic origin, i.e., fractionated REE distribution spectra with an increase in chondrite-normalized values from light to heavy REE, positive Ce anomalies and negative Eu anomalies, and high Th/U ratios(0.59-7.77). In discrimination diagrams based on a series of inter-element relationships, zircon compositions fall into the fields of zircons from rocks of continental crust, mostly granitoids. The Li content of the zircons is high(1.8 ppm-50 ppm),adding further evidence to their derivation from rocks of continental crust. During their residence within young oceanic crust, the zircon xenocrysts experienced alterations under the influence of submarine high-temperature hydrothermal fluids, which selectively affected the distribution of trace elements in the zircons and reduced the δ;O values to 1.75‰-3.15‰. The presence of obviously older zircons

关键词： zircon U-Pb geochronology oxygen isotopes trace elements rare earth elements Shaka Ridge South Atlantic Southwest Indian Ridge

Zircon U-Pb geochronology Recorded Late Cretaceous Fluid Activation in the Central Aldan Gold Ore District, Aldan Shield, Russia: First Data

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Journal of Earth Science 2020年第3期31卷 481-491页

作者： Vasilii I.Leontev Sergey G.Skublov Nadezhda V.Shatova Alexey V.Berezin Faculty of Geological Prospecting Saint Petersburg Mining University199106 St.PetersburgRussia institute of precambrian geology and geochronology of russian academy of sciences 199034 St.PetersburgRussia Karpinsky russian Geological Research institute 199106 St.PetersburgRussia institute of Earth Science St.Petersburg State University199034 St.PetersburgRussia

The gold mineralization in the Central Aldan ore district is genetically related to potassic calc-alkaline and alkaline magmatism dated at 115–150 *** objective of this study is to establish the age of hydrothermal processes that accompanied the formation of Au-Te mineralization at the Samolazovsky *** on the isotope-geochemical study of zircons from quartz-feldspar metasomatic rocks of the deposit,the granitoids and charnokites of the Nimnyr Complex(1900–1960 Ma)at the contact with the Yukhta monzonite-syenite massif(~127 Ma)were *** U-Pb dating was performed on a SHRIMP-II ion microprobe,and rare-earth and trace elements analyses of zircon were carried out in the same craters by secondary-ion mass spectrometry on a Cameca IMS-4f ion *** is revealed that the studied zircons have heterogeneous structures:dark core and lighter rim,which differ greatly in isotope-geochemical *** rims are cut by a network of fractures,extending into the central part of zircon *** rims yield a subconcordant age of 1937±24 Ma,with an average total REE content of 550 ppm,which corresponds to the formation age of the Nimnyr *** zircon cores yield a discordant age of 83±11 Ma and are characterized by a higher total REE content(~1812 ppm),as well as higher contents of U and non-formula elements(Ca,Sr,and Y)with respect to rims,due to the effect of fluid on *** the limited number of zircon grains,the additional geochronological study of zircons from syenites of the ore-bearing Ryabinovy Massif has revealed the presence of two distinct age clusters:~125–138 and 76–83Ма.The older ages of zircons from syenites are typical for the Central Aldan ore *** now,there is still no explanation for an age range(76–83 Ma)of single zircon grains from ore-bearing syenites of the Ryabinovy *** obtained data suggest that the processes of activation(the effect of fluid)within the Central Aldan ore district continued unt

关键词： U-Pb geochronology REE geochemistry zircon Samolazovskoe Deposit Ryabinovoe Deposit Aldan Shield

Tourmalinization at the Darasun goldfield,Eastern Transbaikalia:Compositional,fluid inclusion and isotopic constraints

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Geoscience Frontiers 2012年第1期3卷 59-71页

作者： Vsevolod Prokofiev Ivan Baksheev Lidiya Zorina Boris Belyatsky Vladimir Ustinov Nadezhda Krivitskaya institute of geology of Ore Deposits Petrography Mineralogy & GeochemistryRussian Academy of SciencesMoscowRussia Lomonosov Moscow State University MoscowRussia Lomonosov Moscow State University Moscow Russia Vinogradov institute of Geochemistry Irkutsk Russia institute of precambrian geology and geochronology RAS Saint-PetersburgRussia Vernadsky institute of Geochemistry and Analytical Chemistry RAS MoscowRussia

Zoned tourmaline （schorl-dravite） in the matrix of hydrothermal explosive breccia and ore veins in gold deposits, Chita region, Eastern Transbaikalia, Russia, are associated with Na- and K-rich porphyry-type subvolcanic intrusives. 61So values of tourmaline from three gold deposits （Darasun, Talatui, Teremkinskoye） are ＋8.3%, ＋7.6%, and --6.0% and calculated 6180 values of fluids respon- sible for the tourmalinization are ＋7.3%, ＋7.7%, and ＋4.2%, respectively. These data imply an igneous fluid source, except at the Teremkin deposit where mixing with meteoric water is indicated. Wide ranges of Fe3＋/Fetot and the presence of vacancies characterize the Darasun deposit tourmaline indicating wide ranges off（O2） and pH of mineralizing fluids. Initial stage tourmalines from the gold deposits of the Darasun ore district are dravite or high mg schorl. Second stage tourmaline is characterized by oscillatory zoning but with Fe generally increasing towards crystal rims indicating decreasing temperature. Third stage tourmaline formed unzoned crystals with XMg （mole fraction of Mg） close to that of the first stage tourmaline, due to a close association with pyrite and arsenopyrite. From Fe^3＋/Fetot values, chemical composition and crystallization temperatures, logf（O2） of mineralizing fluids ranged from ca. -25 to 20, much higher than for the gold-bearing beresite-listvenite association, indicating that tourmalinization was not related to gold mineralization.

关键词： Tourmaline composition Fluid inclusions Oxygen isotopes Gold deposits Transbaikalia Russia

Paleoproterozoic,High-Metamorphic,Metasedimentary Units of Siberian Craton

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Acta Geologica Sinica(English Edition) 2009年第5期83卷 875-883页

作者： Lena URMANTSEVA Olga TURKINA institute of geology and Mineralogy Siberian BranchRussian Academy of SciencesNovosibirskRussia

Sensitive, high-resolution ion microprobe zircon U-Pb ages of Paleoproterozoic, high-grade, metasedimentary rocks from the south-western part of the Siberian Craton are reported. Early precambrian, high-grade complexes, including garnet-biotite, hypersthene-biotite, and cordierite- bearing gneisses compose the Irkut terrane of the Sharyzhalgay Uplift. Protoliths of studied gneisses correspond to terrigenous sediments, ranging from greywacke to shale. The paragneiss model Nd ages of 2.4-3.1 Ga indicate Archean-to-Paleoproterozoic source provinces. Zircons from gneisses show corerim textures in cathodoluminescence （CL） image. Round or irregular shaped cores indicate detrital origin. Structureless rims with low Th/U are metamorphic in origin. The three age groups of detrital cores are：〉2.7, -2.3, and 1.95-2 Ga. The ages of metamorphic rims range from 1.86 to 1.85 Ga; therefore, the sediments were deposited between 1.95 and 1.86 Ga and derived from Archean and Paleoproterozoic source rocks. It should be noted that Paleoproterozoic metasedimentary rocks of the Irkut Block are not unique. High-grade metaterrigenous sediments, with model Nd ages ranging from 2.3 to 2.5 Ga, are widely distributed within the Aldan and Anabar Shields of the Siberian Craton. The same situation is observed in the North China Craton, where metasedimentary rocks contain detrital igneous zircon grains with ages ranging from 3 to 2.1 Ga （Wan et al., 2006）. All of these sedimentary units were subjected to Late Paleoproterozoic metamorphism. In the Siberian Craton, the Paleoproterozoic sedimentary deposits are possibly marked passive margins of the Early precambrian crustal blocks, and their high-grade metamorphism was related to the consolidation of the Siberian Craton.

关键词： zircon sensitive high-resolution ion microprobe U-Pb dating metasedimentary rocks,Paleoproterozoic Siberian Craton

Tectonometamorphic Cycles in Different Geodynamic Conditions

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Journal of Earth Science 2000年第4期19卷 11-19页

作者： Miller Yu V Dufour MS institute of precambrian geology and geochronology Russian Academy of ScienceSt-Petersburg 199034Russia Geological Faculty St-Petersburg State University St-Petersburg 199034Russia

Formation and attenuation of crust thermal anomalies, accompanied by development of geological structures, are governed by special laws, together with metamorphism and other endogenic process, form tectonometamorphic cycle (TMC). Because of rock rheology under metamorphic conditions, the structures, concurring with metamorphism, reflect geodynamic conditions much more perfect than those of the structures of nonmetamorphosed rocks. For this reason, structural investigations open wide, sometimes unique, possibilities for geodynamic research into regional metamorphosed terrains. The TMC features under different geodynamic conditions are shown with examples of California (subduction), Himalaya and Junggar Alatau (collision), and Northwest environs of the White Sea (polycyclic development). The analysis of these units serves as basis of some general conclusions. TMC, the steady pattern of crust thermal anomalies manifestation, does not practically depend on peculiarities of metamorphism. At lower and middle crust levels, occur the high-temperature complete cycles that include following two stages. The first is represented by nappes and paragenes of parallel bedding flow, the second, by linear folds, domes and faults. At top levels of fold complexes display the low-temperature reduced cycles, expressed only by structures of the second stage. There are gradual transitions between the complete and reduced cycles. Thermal anomalies in the first stage of complete cycles devolop against the background of large horizontal displacements at contacts between interacting plates or are genetically connected with their gently sloping fault planes. Of all structural elements of the cycles, in compressional environments (nappes, linear folds, domes etc.), only the structures of the first stage of complete cycles can be considered as indications of plate tectonics. Presence of such structures at the most ancient supracrustal complexes point to existence of plate tectonics already at

关键词： complete and reduced tectonometamorphic cycles nappe parallel bedding flow schistosity linear fold dome.

Geological Structure and Historical Development of Pre-Jurrasic Basement of West Siberia Oil- and Gas-Bearing Megabasin Karabash Zone

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Open Journal of geology 2022年第10期12卷 717-738页

作者： Kirill Svjatoslavich Ivanov Nikolay Pavlovich Kostrov Yuriy Viktorovich Erokhin Vladimir Sergeevich Ponomarev institute of geology and Geochemistry Urals Branch of Russian Academy of Sciences Yekaterinburg Russia

An additional comprehensive study of the west Siberia Karabash zone basement has been conducted. Core samples from more than 300 wells that opened the rocks of the basement were analyzed by different methods. A new map of the pre-Jurassic basement of Karabash zone of the west part of the Khanty-Mansi Autonomous Okrug (KhMAO) has been made. For the first time for the West Siberia megabasin U-Pb dating was made for samples from Shaim-Kuznetsovsk meganticlinorium and late to middle Devonian ages were obtained. The Devonian ages was obtained for metamorphic complexes of the region and, in general, for the basement of West Siberia. The complexes considered as precambrian before that. The obtained results enable significantly to clarify more exact history of pre-Jurassic rock forming for the basement of the west part of West Siberia craton and its structure in the limits of Karabash zone. Thus, obtained data testify that in pre-Jurassic basement of the west part of the West Siberia (Karabash zone), filling grabens basalt effusion began during Permian time (probably at the end of early Permian) at sublatitudinal compression, that is, at collision, possibly immediately after or subsynchronously with the origin of the granite. On the edge of Permian and Triassic (or in early Triassic), sublatitudinal compression changed into stretching, and submeridional grabens came to existence and basalt effusion came up to the maximum.

关键词： Zircon Age Definition West Siberia Pre-Jurassic Basement Triassic Graben-Rifts

Gold mineralization age of the Anjiayingzi gold deposit in Chifeng County, Inner Mongolia and implications for Mesozoic metallogenic explosion in North China

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Science China Earth sciences 2004年第2期47卷 115-121页

作者： LI Yonggang ZHAI Mingguo YANG Jinhui MIAO Laicheng GUAN Hong institute of geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

The Anjiayingzi gold deposit in Chifeng County, Inner Mongolia is located in the central part of the gold mineralization belt of the northern margin of the North China Craton (NCC), and is adjacent to the Paleozoic Inner Mongolia-Da Hinggan Mountains orogenic belt in the north. The Chifeng-Kaiyuan fault, which separates the NCC from this orogenic belt, is considered to be a regional ore-controlling structure. The Anjiayingzi gold deposit is a mediate-size quartz lode-gold deposit and is hosted by the Anjiayingzi quartz monzonite that was emplaced into the basement composed of early precambrian gneisses. Rhyolitic and porphyritic dikes are generally associated with the gold mineralization. Zircon U-Pb analyses suggest that the Anjia- yingzi granite was emplaced from 132 Ma to 138 Ma, while the rhyolitic dikes that occupy the same fracture system as the gold-bearing quartz veins and locally crosscut the gold lodes crystallized from 125 Ma to 127 Ma. These results constrain the mineralization age between 126 Ma and 132 Ma, early Cretaceous time for the Anjiayingzi gold deposit. This mineralization age is consistent with that of the gold deposits in other major gold-bearing areas of the NCC, such as the Jiaodong Peninsula and the Xiaoqinling Mountain, and specially is roughly coeval with the geodynamic reversion of the NCC in Mesozoic. This coincidence probably indicates that the gold deposits in the NCC, including the Anjiayingzi deposit, formed in a similar geodynamic setting characterized by large-scale thinning of the lithosphere underlying the NCC.

关键词： Anjiayingzi, gold deposit, granite, zircon, geochronology, explosive metallogeny.

Provenance of precambrian Fe- and Al-rich Metapelites in the Yenisey Ridge and Kuznetsk Alatau, Siberia: Geochemical Signatures

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Acta Geologica Sinica(English Edition) 2007年第3期81卷 409-423页

作者： Igor I. LIKHANOV Vladimir V. REVERDATTO institute of geology and Mineralogy Siberian Branch Russian Academy of SciencesPr. Acad. Koptyuga3Novosibirsk630090Russian Federation

Major, trace and rare earth element contents of Fe- and Al-rich metapelites from the Korda （Yenisey Ridge） and Amar （Kuznetsk Alatau） formations were determined to examine the nature, origin and evolution of their protoliths. Results indicate that these rocks are the redeposited and metamorphosed products of precambrian kaolinitic weathering crusts, while the geochemical distinctions between the studied metapelites are determined by different weathering conditions in the source area and tectonic settings. The protolith of the Korda Formation metapelites was produced by erosion products of the post-Archean granitoid rocks, which accumulated under humid climate conditions in shallow-water basins along the continental margin. The geochemical characteristics of the deeper primary deposits of the Amar Formation suggest that volcanogenic material of mafic composition derived from an island-arc environment had a major role in supplying the erosion zone. These results agree with lithofacies data and with the geodynamic reconstruction of the evolution of the Yenisey Ridge and Kuznetsk Alatau during the Mesoproterozoic and Neoproterozoic, respectively. It was shown that REEs had limited mobility during contact metamorphism. The coherent mobility of REEs during collisional metamorphism may be attributed both to mineral reactions responsible for modal changes and to local chemical heterogeneity inherited from the initial protolith.

关键词： geochemistry protolith pelitic schists Kuznetsk Alatau Yenisey Ridge Russia

Discovery of the Jiawengmen Stromatolite Assemblage in the Southern Belt of Eastern Kunlun, NW China and Its Significance

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Acta Geologica Sinica(English Edition) 2005年第4期79卷 471-480页

作者： BIAN Qiantao ZHU Shixing I. I. POSPELOV M. A. SEMIKHATOV SUN Shufen CHEN Daizhao NA Chunguang institute of geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Tianjin institute of geology and Mineral Resources China Geological Survey Tianjin 300170 China Geological institute Russian Academy of Sciences Moscow 119017 Russia

This paper reports a newly discovered Late Mesoproterozoic-Early Neoproterozoic stromatolite assemblage, named here the ＂Jiawengmen stromatolite assemblage＂, represented by a Conophyton-Baicalia association in the Jiawenmen area in the southern belt of the Eastern Kunlun. This stromatolite assemblage is dominated by large-scale conical stromatolites and related elements, i.e., Conophyton garganicus var. inkeni, C. cf. ressoti Menchikov, Jacutophyton cf., Conicodomenia f., which commonly co-exist with elements of the group of Baicalia. This assemblage can be correlated with that of the middle Jixian-middle Qingbaikou System in North and Northwest China, but is different from that in South China. Correlation can also be made with that in the upper horizon of the Middle Riphean-lower horizon of the Upper Riphean in the South Ural Mountains and Siberia of Russia, in North Africa, and in the Alaskan Peninsula of North America. These facts suggest that the Jiawengmen stromatolite assemblage probably colonized during 1300-850 Ma ago. Accordingly, the stromatolite-bearing carbonate rocks are then proposed to correspond to the middle Jixian System-middle Qingbaikou System or the upper Middle Riphean-lower Upper Riphean. Our stromatolite data further suggest that a precambrian microblock, named the Xialawen microblock here, occurred in the southern belt of Eastern Kunlun, the western part of the Maqên microblock. Similar stromatolite assemblages in the Maqên microblock and those blocks that occurred in North China, Siberia and North Africa point to similar paleogeographic and paleoenvironmental conditions. These microblock and blocks were probably located at low latitudes and on the continental margins of the Rodinian supercontinent, where warm epicontinental seas were favorable to widespread colonization of stromatolites during the Late Mesoproterozoic-Eady Neoproterozoic. However, these stromatolite assemblages are quite different from those of the South China block, which

关键词： stromatolite precambrian Rodinia supercontinent Eastern Kunlun Tibetan Plateau