检索结果-南通市图书馆

China Geology 2024年第1期7卷 63-79页

作者： Viktor Antipin Valentina Makrygina Larisa Kushch Nataliya Sheptyakova vinogradov institute of geochemistry SB RAS664033 IrkutskRussia

The detailed description of two granite complexes in the Olkhon subterrane is *** Early paleozoic Sharanur complex was formed by granitization of gneisses of the Olkhon *** includes migmatites,granite-gneisses,granites and pegmatites of normal alkalinity;they belong to the type of syncollisional *** Middle paleozoic Aya granite complex includes mother Aya massif of amazonite-bearing granites and several types of rare-metal *** have elevated alkalinity,low of Ba,Sr,and high LILE and HFSE elements *** Aya pegmatites lie in northwest cracks of stretching and associated with the rise of the territory under the influence of the North Asian *** cracks and pegmatites mark the beginning of a new intraplate geodynamic *** geochemical types are distinguished among the pegmatites of this *** are amazonite pegmatites of Li-F type with Ta mineralization and complex type pegmatite with Be-Rb-Nb-Ta and Li-F mineralization(the Ilixin vein).The Tashkiney pegmatite vein is similar to Ilixin,but lies in the gneisses of the Olkhon *** shows high concentrations of Be,Nb,Ta,as well as W,Sn,but lacks Li and F,due to a greater depth and higher temperature of the melt crystallization of this pegmatite.

关键词： pegmatite geochemistry Submantle plume Magmatism Caledonian collision Middle paleozoic intraplate setting Be-Rb-Nb-Ta-Li-F mineralization Olkhon region Russia

Major- and Trace- Element Chemistry of Clinopyroxene and Amphibole from High-Mg Diorite in Chelyabinsk Massif(Urals): Insights into petrogenesis and Magma Source Constraints

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年

作者： Tatiana Osipova Gennadiy Kallistov Maria Chervyakovskaya Vasiliy Chervyakovskiy Zavaritsky institute of Geology and geochemistry，Ural Branch of ras

Field- and petrographic investigations， together with microanalytical major- and trace-element studies， were carried out on clinopyroxene and amphibole from high-Mg diorite in the subduction-related Chelyabinsk granitic massif to understand its petrogenesis and source. The clinopyroxene composition (high Mg#， Cr-content， sum of REE and Ti/Eu ratio; depletion in HREE; negative Eu-anomaly) indicates that it formed from a reduced melt derived from a mantle source metasomatized by fluids/melts having crustal affinity. Melt compositions in equilibrium with clinopyroxene and amphibole were calculated using solid/liquid partition coefficients. The high Nb/Y and Zr/Y ratio values of a liquid simulated from clinopyroxene， which appears to have very similar characteristics to sanukitoid melts， indicate a low degree of melting of the mantle source. Melt simulated from amphibole is more evolved and more felsic (dacitic). It displays a geochemical “amphibole fractionation” signature， indicating the peritectic transformation of clinopyroxene to amphibole in the lower crust. Rock textures and major element mineral compositions suggest that further amphibole was precipitated directly from the melt in the middle crust. The results show that the Chelyabinsk high-Mg diorite was probably formed as a cumulate from sanukitoid-like melt during its ascent and cooling below dacitic liquidus inside the amphibole stability field.

关键词：

A new tectonic model for the Itmurundy Zone,central Kazakhstan:linking ocean plate stratigraphy,timing of accretion and subduction polarity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第4期15卷 245-273页

作者： Inna Safonova Ilya Savinskiy Alina perfilova Olga Obut Alexandra Gurova Sergei Krivonogov Southwest Jiaotong University Xi’an Road 999ChengduChina Sobolev institute of Geology and Mineralogy SB RASKoptyuga Ave.3NovosibirskRussia Novosibirsk State University Pirogova St.2NovosibirskRussia Trofimuk institute of petroleum Geology and Geophysics sb ras Koptyuga Ave.3NovosibirskRussia

The Itmurundy Zone of Central Kazakhstan is a key structure in the core of the Kazakh Orocline representing a typical pacific-type orogenic belt hosting accretionary complex,ophiolite massifs and serpentinite mé*** main controversies in the existing tectonic models of the Itmurundy Zone are about the timing of subduction and accretion,the direction and kinematics of subduction and the number of oceanic plates.A new model for the early paleozoic tectonic story of the Itmurundy Zone is postulated in this paper,based on new detailed geological and U-pb detrital zircon age data,combined with previously documented geological,U-pb age,microfossil,geochemical and isotope data from igneous rocks,deep-sea sediments and greywacke *** present study employs the Ocean plate Stratigraphy(OpS)model to explain the tectonic processes involved in the evolution of the Itmurundy Zone and to pre-sent a holistic story of Ordovician oceanic plate(s),which accretion formed an accretionary *** detailed mapping allows distinguishing three types of OpS assemblages:(1)Chert-dominated,(2)OIB-hosting,and(3)*** U-pb ages of detrital zircons from sandstones of OIB and Chert types show unimodal distributions with similar main peaks of magmatism at 460-455 Ma in the provenance,and their maximum depositional ages(MDA)span 455-433 *** samples from OpS Type 3 show the peaks of magmatism both at ca.460 Ma and the MDA of 452 Ma and 459 Ma,*** MDA of sandstones and microfossils data from chert show the younging of strata to the south and SE in Types 1 and 2 and to NEE for Type 3(in present coordinates)suggesting double-sided subduction to the NNW and SEE and,accordingly,the co-existence of pieces of two oceanic plates in Ordovician *** U-pb zircon data from both igneous and clastic rocks indicate a period of subduction erosion in early Ordovician *** a whole,the accreted OpS units of the Itmurundy Zone record the timing of subduction and accre

关键词： Central Asian Orogenic Belt Accretionary complex Magmatic rocks Sedimentary rocks Subduction polarity Lithospheric plates

geochemistry and petrology of superpure quartzites from East Sayan Mountains, Russia

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2019年第1期38卷 22-39页

作者： A.M.Fedorov V.A.Makrygina A.I.Nepomnyaschikh A.p.Zhaboedov A.V.parshin V.F.posokhov Yu.V.Sokolnikova a.p.vinogradov institute of geochemistry sb ras Irkutsk National Research Technical University Irkutsk Scientific Center sb ras Irkutsk State University Geological institute sb ras

Quartzites are widespread within Earth's lithosphere, but their highly pure varieties occur quite infrequently. With the development of alternative energy sources, including solar, and with increasing demand for high-purity quartz for optics, interest has risen in highpurity silicon-bearing materials. The quartzites discovered in the southeast part of the Eastern Sayan Mountains are particularly attractive for exploration in terms of their raw material quality and feasibility to be enriched. For this reason, their genesis also merits study. Available geochemical data show that chemogenic(d^(18)O>29.2%)siliceous-carbonate sediments of the Irkut Formation are fairly pure(impurity elements ppm), and that half the impurities are easily removed carbonate components of the rock. Bedded quartzites remote from the intrusive granitoids and near-contact quartzites were recognized based on geochemical and petrographic data. Influenced by the Sumsunur granitoids, the near-contact quartzites originally contained >0.9% impurities, but later, under the action of sliding slabs of ophiolite dynamothermal treatment reduced impurities to ppm, resulting in ‘‘superquartzites' '(highly pure quartzites). The presence of only minor structural impurities is due to the enrichment capacity of superquartzites to 10.1 ppm(7.2 ppm under special conditions) of 10 elements: Fe, Al, Ti, Ca, Mg, Cu,Mn, Na, K, and Li.

关键词： High-purity quartz Superquartzite Gravitational sliding Dynamic metamorphism Recrystallization

Study of asphaltene reaggregation in toluene/heptane mixture by dynamic and static light scattering

在线全文

学校读者我要写书评

暂无评论

petroleum Research 2024年第1期9卷 48-54页

作者： Vladimir N.Kuryakov Oil and Gas Research institute of ras(OGRI ras) Gubkina Str.3119333MoscowRussian Federation

This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution,conducted with dynamic light scattering *** objects of the study were four samples of asphaltenes obtained from four different *** all samples,the change in the average size of the asphaltene submicron aggregates with time was measured after the addition of a precipitant(heptane)to a solution of asphaltenes in toluene at an amount above the threshold *** aggregates formed in solution after the addition of the precipitant and were subjected to ultrasonic treatment,which led to the destruction of the asphaltene *** of destroyed asphaltenes was *** kinetics of this aggregation were similar to the kinetics of aggregation of asphaltenes after the addition of a *** iterations of asphaltene aggregate destruction in the sample led to a significant change in the kinetics of aggregation:the growth of aggregates slowed and stabilized at a size of approximately 200 nm and 30 nm for the different studied samples.

关键词： Asphaltenes Aggregation Sonication Dynamic light scattering Re-aggregation Colloidal stability Resins

Nature and(in-)coherent metamorphic evolution of subducted continental crust in the Neoproterozoic accretionary collage of SW Mongolia

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2021年第3期12卷 78-103页

作者： Sergei Skuzovatov vinogradov institute of geochemistry sb ras Favorskogo str.1AIrkutsk 664033Russia

In continental subduction complexes minor volumes of high-pressure mafic rocks(eclogites)often co-exist with much more abundant felsic(granitic)and metasedimentary rocks,which are vital for resolving the origin and metamorphic evolution of subducted continental *** SW Mongolia,the Alag Khadny eclogite-bearing accretionary complex(AKC)is assumed to represent either a remnant of oceanic slab,or a continental margin,subducted in the Early *** we present geochronological,geochemical and petrological evidence of subduction records for the three major types of lithologies that host mafic eclogites,including Mesoproterozoic and Neoproterozoic granitic basement and overlying Neoproterozoic continental-margin *** deformed,ferroan and peraluminous metagranitoids compose a major part of AKC and are interlayered with eclogites in its southern and eastern *** have geochemical features of post-collisional/intraplate high-K calc-alkaline ***-ICp-MS U-pb zircon geochronology of three distinct metagranite samples show uniform protolith crystallization ages of ca.0.96 Ga and uncertain re-crystallization in the Late Neoproterozoic or Early paleozoic metamorphic event,whereas abundant zircon inheritance indicates older,Mesoproterozoic to paleoproterozoic crustal substrate during granite *** existence of Mesoproterozoic crust is highlighted by finding of distinct metagranitoids with the U-pb zircon crystallization age of ca.1.6 *** isotope signatures(T_(DM)^(C)2.88-1.85 Ga)of zircons from all lithologies preserved the evidence of reworked Neoarchean to paleoproterozoic crust,similar to that of the Baidrag block(southern Mongolia),for both Mesoproterozoic and Neoproterozoic *** of the specific lithology,the rocks display indicators of high-pressure metamorphic re-equilibration,including garnet(X_(Ca)up to 0.65)+epidote+phengite(Si *** to 3.56)±rutile assemblage in metagranitoids,garnet+phengite(Si ***

关键词： Central Asian Orogenic Belt SW Mongolia Subduction Metasedimentary rocks Orthogneisses Trace elements Zircon U-pb age Hf isotopes

Low-altitude geophysical magnetic prospecting based on multirotor UAV as a promising replacement for traditional ground survey

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2018年第1期21卷 67-74页

作者： Alexander V.parshin Vladimir A.Morozov Anton V.Blinov Alexey N.Kosterev Alexander E.Budyak Ore Geology Lab Vinogradov Institute of Geochemistry SB RASIrkutskRussia SibGISTech LLC MarkovaRussia Geoinformatics Lab Irkutsk National Research Technical UniversityIrkutskRussia

The prospects for expanding the mineral resource base in many countries are linked with the exploration of stranded sites localized at unexplored areas with complex natural and landscape conditions that make any ground survey,including magnetic prospecting,difficult and *** current level of geology requires high-precision and large-scale data at the first stages of geological *** 2012,technologies of aeromagnetic surveying with unmanned aircraft vehicles(UAV)enter the market,but most of them are based on big fixed-wing UAV and do not allow to substantially increase the level of survey granularity compared with traditional aerial *** increase the scale of survey,it is necessary to reduce the altitude and speed of flight,for which the authors develop the methodical and technical solutions described in this *** obtain data at altitudes of 5 m above the terrain even in a rugged relief,we created heavy multirotor UAVs that are stable in flight and may be used in a wide range of environmental conditions(even a moderate snowfall),and develop a special software to generate flight missions on the basis of digital elevation models.A UAV has special design to reduce magnetic interference of the flight platform;the magnetic sensor is hung below the *** technology was conducted in a considerable amount of magnetic surveys in the mountainous regions of East Siberia between 2014 and *** results of the comparison between airborne and ground surveys are presented,which show that the sensitivity of the developed system in conjunction with low-altitude measurements can cover any geologically significant anomalies of the magnetic *** unmanned survey is cheaper and more productive;the multirotor-based technologies may largely replace traditional ground magnetic exploration in scales of 1:10,000−1:1000.

关键词： Unmanned aircraft vehicles(UAV) magnetic survey geophysical prospecting airborne geophysics unmanned aerial system(UAS)

The Sytykanskaya kimberlite pipe:Evidence from deep-seated xenoliths and xenocrysts for the evolution of the mantle beneath Alakit,Yakutia,Russia

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2015年第5期6卷 687-714页

作者： I.V.Ashchepkov A.M.Logvinova L.F.Reimers T.Ntaflos Z.V.Spetsius N.V.Vladykin H.Downes D.S.Yudin A.V.Travin L.V.Makovchuk V.S.palesskiy O.S.Khmel'nikova institute of Geology and Mineralogy sb ras Vienna University Alrosa Stock Company institute of geochemistry sb ras Birkbeck College University of LondonUKMalet Street

Mantle xenoliths（>150） and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field（Yakutia） were analyzed by EpMA and LAM ICp *** p-TX-f（O2） diagrams minerals from xenoliths show widest variations,the trends p-Fe#-CaO,f（O2）for minerals from porphyric kimberlites are more stepped than for xenocrysts from *** pTX points mark moving for protokimberlites from the lithosphere base（7.5 Gpa） to pyroxenite lens（5-3.5 Gpa） accompanied by Cr increase by AFC and creation of two trends p-Fe#OI10-12%and13-15%.The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 Gpa and 600 C near Moho was *** oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere *** inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated *** for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider *** reveal S-shaped REE *** clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC *** for garnets display less inclined patterns and Ba-Sr troughs but enrichment in ***40Ar/39Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal proterozoic（1154 Ma） age of metasomatism in early Rodinia *** glimmerites with richterite- like amphiboles mark1015 Ma plume event in Rodinia ***600-550 Ma stage manifests final Rodinia *** last 385 Ma metasomatism is protokimberlite-related.

关键词： Kimberlites Mantle lithosphere Mantle xenoliths Th

prognosis of the state (eutrophication and pollution) of freshwater ecosystems on the example of long-term research into Lake Baikal

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of geochemistry 2006年第B8期25卷 144-145页

作者： Eugenia N. Tarasova Alexander A. Mamontov Elena A. Mamontova A.p. vinogradov institute of geochemistry sb ras

Monomineral universal clinopyroxene and garnet barometers for peridotitic,eclogitic and basaltic systems

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2017年第4期8卷 775-795页

作者： I.V.Ashchepkov T.Ntaflos A.M.Logvinova Z.V.Spetsius H.Downes N.V.Vladykin V.S.Sobolev institute of Geology and Mineralogy sb ras Vienna University Alrosa Stock Company Department of Earth and planetary Sciences Birkbeck University of London institute of geochemistry SD ras

New versions of the universal Jd-Di exchange clinopyroxene barometer for peridotites,pyroxenites and eclogites,and also garnet barometer for eclogites and peridotites were *** were checked using large experimental data sets for eciogitic（~530） and peridotitic systems（〉650）.The precision of the universal Cpx barometer for peridotites based on Jd-Di exchange is close to Cr-Tschermal

关键词： Clinopyroxene Barometer peridotite Eclogite Kimberlite Garnet