Litosfera最新文献

{"title":"Petrological-geochemical features of ore-bearing effusive and intrusive rocks of the Nikolaevskoe gold-porphyry deposit (the Southern Urals)","authors":"S. E. Znamensky, V. V. Holodnov","doi":"10.24930/1681-9004-2018-18-4-607-620","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-4-607-620","url":null,"abstract":"Object. The article considers the results of geochemical studies of ore-bearing effusive and intrusive rocks of the Nikolaevka gold deposit, located in the zone of the Main Uralian fault in the Southern Urals. The deposit belongs to the gold-porphyry type which unconventional for the Urals and poorly studied here. Methods. The rock composition was determined by chemical analysis (IG UFRC RAS), mass-spectrometry with inductively coupled plasma on the ELAH 9000 quadrupole mass-spectrometer (IGG UB RAS) and X-ray fluorescence analysis on the VRA 30 spectrometer (IG UFRC RAS). Results. It is established that gold-porphyry mineralization associated with an island-arc volcanic-intrusive complex that unites plagiophyric and pyroxene-plagiophyric basalts, their tuffs, gabbro intrusions and ore-bearing series of dikes plagiophyric dolerite-porphyrites and gabbro-diorite-porphyrites. The rocks of the complex, including ore-bearing dikes, have normal alkalinity, tholeitic and transition from tholeitic to calc-alkaline composition. Among the volcanogenic formations, faunistically dated in the zone of the Main Ural fault in the Southern Urals, by a number of geochemical parameters (for example, the ratios of Zr/Nb and Nb/Th) the effusive and intrusive rocks of the deposit are the closest to the volcanics of the pyrite-bearing Baymak-Buribay Formation (D 1 e 2 ), lying at the base of the section of the Magnitogorsk island arc, and, in all probability, are their age analog. At the same time, the gold-bearing complex differs from the Baymak-Buribay Formation by a general increased iron and titanium content, with a reduced magnesia of all rock types, as well as the absence of boninites and acid volcanics, the predominance of porphyry rock types, which can be due to the geodynamic conditions of its formation. Conclusion. Geodynamic analysis of geochemical data using diagrams (La/Sm)N–TiO 2 and V–Ti/1000 suggests that the Nikolaevka deposit was formed in the articulation zone of the island arc and the back-arc basin. Gold-porphyry mineralization associated with the Late Emsian volcanic processes was isolated in the Southern Urals for the first time.","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86804665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hafnium isotope composition of zircon from the platinum-bearing Feklistov massif (Shantar Archipelago, Sea of Okhotsk, Russia)","authors":"K. Malitch, I. Badanina","doi":"10.24930/1681-9004-2018-18-4-585-592","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-4-585-592","url":null,"abstract":"Object. This study firstly evaluates Hf-isotope characteristics of zircons from wehrlite of the platinum-bearing Feklistov massif, which is closely associated with platinum coastal placer deposits. Materials and methods. In-situ Hf-isotope data were collected on the dated spots within zircon grains using a New Wave LUV213 laser-ablation microprobe attached to a Nu plasma MC-ICP-MS. Resuts. Significant variations of 176 Hf/ 177 Hf i (0.28241-0.28312) and eHf(t) (from -4.8 ± 1.1 to 20.3 ± 0.6) in Paleozoic zircons indicates interaction of a ‘juvenile’ mantle source (eHf(t) ≈ 15) with distinct magma sour­ces, possibly equivalent to a subcontinental lithospheric mantle and/or a continental crust (eHf(t) от -5 до +5). Proterozoic and Late Archean zircons from the Feklistov massif are characterized by less pronounced 176 Hf/ 177 Hf i (0.28107-0.28224) and eHf(t) (from -4.8 ± 0.4 to 8.1 ± 0.6). Conclusion . Hf-isotope features for majority of Precambrian zircons from the Feklistov massif (eHf(t) from -3.8 ± 0.5 to +2 ± 0.5) are consistent with their xenogenic nature and inheritance from basement rocks of the Siberian Craton.","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72977938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acid volcanism of various geotectonic situations (on the example of orogenic volcanic belts in Asia)","authors":"A. M. Kurchavov","doi":"10.24930/1681-9004-2018-18-3-327-340","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-3-327-340","url":null,"abstract":"Кремнекислый вулканизм (кремнекислыми считаются породы с содержанием кремнезема более 64 мас. %) наиболее широко представлен в орогенных вулканических поясах (окраинно-кон тинентальных и коллизионнных) и в энсиалических островных дугах (на континентальной стадии их развития). На ранней стадии формирования этих структур кремнекислые вулканиты входят в состав последовательно дифференцированных базальт-андезит-дацит-риолитовых формаций, на поздней стадии они слагают бимодальные (контрастные по кремнезему) формации повышенной щелочности. Расцвет кремнекислого вулканизм приходится на среднеорогенную стадию в виде риолит-риодацитовых извержений, часто в форме игнимбритов. В породах разных стадий наблюдаются вариации содержаний калия и натрия. Наиболее выдержаны по соотношению калия и натрия среднеорогенные кремнекислые вулканиты, в то время как ранние и особенно позднеорогенные породы широко варьируют по этим параметрам. В целом кремнекислые вулканиты орогенных поясов более щелочные и калиевые, чем породы энсиалических островных дуг. Вкрест простирания орогенных поясов существенно меняются петрохимические особенности вулканитов. Во фронтальных зонах преобладают породы низкокалиевой ветви известково-щелочной петрохимической серии, в тыловых зонах развиты породы высококалиевой ветви этой серии и шошонит-латитовой петрохимической серии. Появление кремнекислых вулканитов в большом объеме и повышенная их щелочность коррелируют со зрелостью континентальной коры, при суммарном воздействии на гранитно-метаморфический слой тепла более глубинной базальтовой магмы, трансмагматических флюидов и ремобилизованных “коровых” летучих компонентов.","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81281283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New data on geochemical features, fluid mode, age and potential ore content of granitoids of Isherim anticlinorium (North Ural)","authors":"G. Petrov, Uralian Geology-Survey expedition, V. V. Holodnov, Y. Ronkin","doi":"10.24930/1681-9004-2018-18-3-416-434","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-3-416-434","url":null,"abstract":"Гранитоиды Ишеримского антиклинория – одной из крупных докембрийских структур Северного Урала – слабо изучены современными геохимическими и изотопно-геохронологическими методами, чем объясняется существование разных точек зрения на условия формирования и возраст этих пород. Авторами выполнены исследования состава пород трех массивов – Вёлсовского, Мойвинского и Посьмакского, методами химического анализа и ICP-��, определение возраста по цирконам методами LA-ICP-�� и �HRI�P, а также изучен состав породообразующих и акцессорных минералов при помощи микроанализатора ��-100. �то позволило получить принципиально новые данные о возрасте, флюидном режиме формирования и потенциальной рудоносности гранитоидов. Показано, что гранитоиды, по всей вероятности, были сформированы в обстановках активной окраины и орогена; первые имеют вендский (567.2–558 млн лет), вторые – кембрийский (530.3–511.1 млн лет) возраст. Дискретные интервалы формирования и достаточно существенные геохимические различия докембрийских и палеозойских гранитов позволяют отнести их к разным комплексам – вендскому мойвинскому и кембрийскому вёлсовскому. Выделенные комплексы различаются и по составу флюидов, которые менялись со временем от существенно хлороносных до фтороносных. С более древними (вендскими) гранитоидами Мойвинского массива может быть связано золотосодержащее �o-� оруденение, а с кембрийскими гранитами Вёлсовского массива – редкометалльная минерализация (�, Nb, Ta, TR).","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86219636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geological and isotope-geochemical criteria of evident presence of ancient continental crust in Primorye basement","authors":"S. Maksimov, P. L. Nevolin, V. Kiselev","doi":"10.24930/1681-9004-2018-18-3-390-415","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-3-390-415","url":null,"abstract":"Совокупность структурно-тектонических, литолого-минералогических, изотопно-геохимических данных по геологии Приморья и соседних территорий Северо-Восточного Китая и Приамурья позволяет обосновать критерии существования в его фундаменте древней сиалической коры. Главными из них являются следующие. 1. Мезозойские терригенные породы складчатых комплексов Приморья характеризуются протерозойским модельным возрастом с удревнением для аркозов до 2460 млн лет (TNdDM2). Они слагаются преимущественно гранитметаморфической минеральной ассоциацией и содержат детритовые цирконы с возрастом до 2500 млн лет. В составе терригенного флиша преобладают аркозы. 2. На территории Юго-Западного Приморья развиты покровы кайнозойских базальтов с протерозойскими модельными возрастами и аномально низкими изотопными отношениями свинца [Pb206/Pb204], аналогичными базальтам древних [AR-PR1] литосферных блоков. 3. Структурный план деформационной тектоники отражает существование единого древнего жесткого каркаса территории, конформно реагирующего на смену режимов сжатия-растяжения в течение длительных временных циклов. 4. В Приморье и Приамурье распространены проявления калиевого, высокобариевого базит-ультрабазитового магматизма с геохимическими чертами кимберлитов-лампроитов. Подобный тип магматизма не характерен для областей с ювенильной корой и отражает существование под этой территорией зрелой континентальной литосферы. С позднего протерозоя сиалическая кора последовательно подвергается деструкции в ходе деламинации и базификации.","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81894130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bismuth sulfosalts from Berezovsk ore region: Chemical composition and mineral associations","authors":"S. V. Pribavkin, S. G. Sustavov, I. Gottman","doi":"10.24930/1681-9004-2018-18-3-445-458","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-3-445-458","url":null,"abstract":"висмутин-айкинитовая The paper presents the results of a study of the chemical composition of the sulfosalts of bismuth from the gold-quartz- sulphide ore Berezovsky Deposit and the eponymous ore district of the Middle Urals. Samples of minerals were obtained from quartz veins located in different parts of the ore area. In the South of the district the veins occur among the granites of the Shartash massif and accompanied by the metasomatic gumbeit formation. Veins in its Central part are located into the dikes of granite porphyry, volcanic-sedimentary rocks, hyperbasites. In the North, the veins are localized in gabbro, hyperbasites, volcanic rocks. Here, as in the Central part, they are accompanied by metasomatic changes of the berezite-listwanite formation. The minerals of bismuth form small isometric, prismatic or needle-shaped secretions, as well as large elongated crystals reaching a length of several centimeters. Their diagnosis and study of the composition was performed by X-ray structural and chemical microanalysis. It is shown widespread among minerals of bismuth sulfosalts of the bismuthinite-ЛИТОСФЕРА aikinite series, consisting of 9 members: bismuthine, pecoite, gladite, stroking, salzburger, krupkaite, lindströmite, khammarite, fridrikhite and dramatically prevalent among sulfosalts that number aikinite. In mineral composition pavonite series revealed cuprapawonite, Cu-benjaminite, benjaminite. Other sulphosalts of bismuth are presented kosalite, nafildite, hodrushite, matildite. The relationship of minerals with each other and the peculiarities of the chemical composition allowed to distinguish several paragenetic associations conform with different stages of mineral formation. With high-temperature stage (360–285°C) connects the deposition of disordered solid solutions bismuthine-aikinte and pavonite series, subsequently undergone to disintegration with the formation of ordered phases of bismuthine, gladite, krupkaite, lindströmite, khammarite, benjaminite. For medium and low temperature stage (285–150°C) was formed aikinite, fridrikhite, krupkaite, salzburgite, nuffieldite cozalite, matildite, together with the Ag-Bi-Galena, tetradymite, hessite and gold. The low-temperature stage is associated with the formation of aikinite together with Galena and gold. Established on the example of the sulfosalts of bismuth sequence of mineral formation reflects not only the consistent evolution of mineral-forming fluids, but the pulsed nature of the hydrothermal activity at individual deposits and at ore field in general.","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72519387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mineralogy of alluvial sediments of Avzyan gold region (the Southern Urals)","authors":"E. Palenova, K. Novoselov, E. Belogub, I. Blinov, Svetlana D. Grigor’eva","doi":"10.24930/1681-9004-2018-18-3-459-474","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-3-459-474","url":null,"abstract":"Introduction. The Avzyan gold region is located within the Bashkirian anticlinorium and includes lode gold deposits and placers. The Gorny Priisk, Bogryashka and Ulyuk-Bar gold deposits are hosted in the Riphean metamorphosed carbonaceous sequence. The article describes the mineralogy of the heavy concentrates from alluvial sediments of the streams of Bolshoy Avzyan basin which drains the Gorny Priisk, Bogryashka and Ulyuk-Bar gold ore deposits. The comparison of mineralogical and chemical feature of the studied heavy concentrates is done. Samples and Methods. Samples from the streams were collected every 50–100 m. Hand specimens of ore and host rocks from the lode gold deposits were collected from outcrops and dumps. The content of metals in the heavy concentrates estimated using X-ray fluorescence analyzer Innov-X alfa. Chemical composition of the accessory minerals was studied using electron microscope Vega-3 Tescan with EDA X-Act Oxford. Discussion and Results. The source of the alluvial sediments was the lode gold deposits located in the immediate vicinity of placers. Heavy concentrates of the Kamenny stream are characterized by a high content of As and Cu while ones of the Bogryashka and Bolshoy Klyuch streams show a high content of Cr and Ba. Goethite is major ore mineral for all studied samples. Ilmenite, rutile, epidote and barite are also widespread in the samples from the Bogryashka and Bolshoy Klyuch streams. Native gold is present in the sediments of all studied stream. The greatest number of gold grains was found in the samples from the Bolshoy Klyuch stream. The weak roundness of the golds and the presence of unoxidized sulfides (pyrite, chalcopyrite and pyrrhotite) indicate a relatively small age of placers. Monazite and xenotime morphology suggests autigenic catagenetic and/or metamorphic origin. Monazite contains (apfu) Ce (0.27–0.56), Nd (0.10– 0.37) and La (0.09–0.33), minor Pr, Sm, Gd, Eu and Dy; ThO2 up to 9.78 wt. % (0.08 apfu). It is similar with monazite composition from other streams of the east part of the Bashkirian anticlinorium and can be evidence of their similar origin. Xenotime contains major Gd, Dy and Er and minor Tb and Ho. Xenotime from the Bogryashka stream is characterized by the increased concentration of (apfu) Gd (0.10–0.24), Nd (0.01–0.02), Sm (0.03–0.06), Eu (0.02–0.06) and absence of Ho and Yb. Xenotime composition from the Kamenny and Bolshoy Klyuch streams is similar with ones from east part of the Bashkirian anticlinorium. Galena inclusions in REE phosphates, monazite inclusions in goethite and xenotime inclusions in pyrite can be evidence about similar conditions and time of formation gold-sulfide and REE mineralization.","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"129 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74146397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Сonodonts from the boundary Artinskian-Kungurian deposits of Mechetlino section (Bashkortostan, the South Urals). Article II. Stratigrafic distribution of conodonts","authors":"V. Chernykh","doi":"10.24930/1681-9004-2018-18-3-363-381","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-3-363-381","url":null,"abstract":"They are represented in the Table X: Neostreptognathodus aff. clinei Behnken, N. clinei Behnken, Sweetognathus nov. sp. 2 , Uralognathus cochleatus Chern. Section Mechetlino is recommended as limitotype of lower boundary (GSSP) of the Kungurian stage of the International stratigraphic scale.","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78252020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bismuth-nickel mineralization in chromitites of Mariinskii deposit (Urals emerald mines)","authors":"M. P. Popov, Yu. V. Erokhin, V. Khiller","doi":"10.24930/1681-9004-2018-18-3-435-444","DOIUrl":"https://doi.org/10.24930/1681-9004-2018-18-3-435-444","url":null,"abstract":"","PeriodicalId":32819,"journal":{"name":"Litosfera","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82004284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}