Structural Evolution of Ore-Controlling Trans-Crustal Faults of the Olchan-Nera Zone: Constraints from the Khangalas Ore Cluster, Yana-Kolyma Metallogenic Belt, NE Russia

The article studies the structural evolution of ore-controlling trans-crustal faults of orogenic deposits and occurrences of the Khangalas ore cluster located in the southeastern part of the Olchan–Nera metallogenic zone, in the Upper Indigirka sector of the Yana–Kolyma metallogenic belt, North–East of Russia. Studies have shown that the formation of tectonic structures occurred during four Mesozoic deformation stages. Accretionary thrust stage D1 resulted in formation of the main pattern of the Mesozoic tectonic structures of the region. Further tectonic evolution occurred in a strike–slip setting of the accretionary D2 and post-accretionary D3–D4 stages. Post-ore strike-slip faults activate and complicate the earlier formed structures of the reverse and thrust paragenesis. Mineralization associated with the strike-slip faults has not been established, whereas formation of the gold-antimony mineralization is associated with sinistral strike–slip faults in the Adycha–Taryn metallogenic zone located to the southwest. The new data obtained are consistent with the previously proposed model of the evolution of the deformation structures of the Khangalas deposit.

Fluid Evolution of the Čukaru Peki Cu-Au Porphyry System (East Serbia) inferred from a fluid inclusion study

Čukaru Peki is a recently discovered copper-gold deposit in the Bor metallogenic zone in east Serbia. Three types of mineralization can be distinguished in this ore deposit: porphyry, high-sulphidation, and transitional epithermal type. This research was focused on fluid inclusion analysis of genetically different veins from the porphyry and the transitional zones of Čukaru Peki with an aim of better understanding the fluid evolution and mineralization processes in this system. Seven types of veins were identified in the porphyry zone of Čukaru Peki and four of these veins contained transparent minerals which were suitable for fluid inclusion analysis. Eight types of inclusion assemblages were distinguished in these veins: type 1 – primary inclusions with homogenization temperatures above 550°C and high salinity, type 2a- scattered polyphase inclusions two salt crystals, type 2b-polyphase inclusions with two salt crystals in crystal growth zones, type 3- brine inclusions with one salt crystal in crystal growth zones, type 4- vapour-rich inclusions, type 5- primary inclusions in anhydrite, and types 6 and 7- secondary low-temperature inclusions This research suggests that saline fluids (30-40% wt.% NaCl eq.) were the most important ones for the formation of porphyry-type mineralization and that the mineralization was formed at temperatures between 350 and 450°C and pressures between 100 and 500 bars. The epithermal stage was characterized by cooler low-salinity fluids with temperatures between 150-350°C, and salinity between 0 and 7 wt.% NaCl eq.

Mineralogical Setting of Precious Metals at the Assarel Porphyry Copper-Gold Deposit, Bulgaria, as Supporting Information for the Development of New Drill Core 3D XCT-XRF Scanning Technology

A petrographic investigation of ore samples from the Assarel porphyry copper deposit in the Srednogorie metallogenic zone (Bulgaria) constrains the setting and character of precious metals (Au, Ag, PGE) and related minerals within the deposit. This work supports renewed interest in understanding the deportment of precious metals and provides mineralogical knowledge during the testing and validation of novel drill core 3D X-ray computed tomography–X-ray fluorescence (XCT-XRF) scanning technology being developed as part of the X-MINE project. Scanning electron microscopy–energy dispersive spectrometry (SEM-EDS) results indicate precious metals occur in their native state (Au, Ag), as sulfides (Ag), sulfosalts (Au), tellurides (Ag, Pd), and selenides (Ag), and typically form micron-sized inclusions in pyrite and chalcopyrite or are disseminated in the groundmass of the rock. Preservation of early Fe oxide–chalcopyrite ± bornite assemblage as relics in the more dominant pyrite-chalcopyrite mineralization assemblage supports mineral disequilibrium relationships and multi-stage mineralization events. Several rare minerals (e.g., merenskyite, acanthite, sorosite, tetra-auricupride, auricupride, greenokite, bismuthinite, nagyagite, native Ni) are reported for the first time at Assarel and highlight the mineralogical diversity of the ore. The occurrence of precious metals and related minerals at Assarel attest to a complex hydrothermal system that underwent progressive physicochemical changes during the evolution of the mineralizing system (e.g., redox conditions, fluid chemistry).

POLYMETALLIC AND GOLD-SULFIDE-QUARTZ WITH EPG MINERALIZATION, IN THE TOAR -AALEN CARBONTERRIGENOUS FLYSCHOID (BLACK SHALE) STRATA OF THE FIAGDON-TEREK METALLOGENIC SUBZONE OF THE SAMUROBELORECHENSK METALLOGENIC ZONE (NORTH CAUCASUS)

В последнее время в области геологии золоторудных месторождений фундаментальной проблемой является выявление характера и причин платино- и палладиеносности золоторудных месторождений, установ- ленной для ряда месторождений Дальнего Востока, Чукотки, Северо-Восточной Азии, Урала, Тянь-Шаня, Цен- тральной России (железистые кварциты гигантских по запасам месторождений КМА и ВМА), а в последние 15 лет – и Северного Кавказа, где было выявлено Au-Pt-Pd-оруденение, ассоциирующее с черными сланцами девона. В 2018 г. нами был выявлен новый источник благороднометалльной (Au-Pt-Pd) минерализации, ассоциирующий с ранне-среднеюрскими черными сланцами на территории Горной Осетии. В статье приведена информация о эво- люции металлогении этой части Северного Кавказа в киммерийскую эпоху. Приведены главные результаты по- исковых работ на золото-серебряный и золото-сульфидный типы оруденения в Горной Осетии, проведенных ОАО «Севосгеологоразведка»и АО «Северо-Кавказское ПГО» в пределах Какадур-Ламардонской рудной зоны, входящей в состав Авсандур-Ламардонского рудного поля. Установлено, что тоар-ааленская углеродисто-терригенная флишоидная (черносланцевая) толща, вмещающая жильные полиметаллические месторождения Какадур-Хани- комское и Кадат-Хампаладагское, а также перспективные рудные тела с жильным и штокверковым золотосо- держащим свинцово-цинковым и золото-сульфидно-кварцевым типами оруденения, обладает повышенной (для S, Fe2O3, Cr, Ni, Cu, Zn, As, Zr, Pb, Sb, Rb, Ag, Au, Pd, Pt, Ru) металлоносностью. Комплексный анализ полученных данных позволяет считать, что главным механизмом формирования благороднометалльного оруденения была конвекция. «Триггером» для ее запуска могли служить зоны активных разломов, разнознаковые перемещения по которым привели, за счет трения, к разогреву черносланцевых толщ. В результате происходила конвекция разо- гретых в тектонически активных зонах вадозных вод, находящихся в черносланцевых толщах, и их перемещение во фронтальную часть возникшей гидротермально-метасоматической колонны. Такая тектоническая актив- ность проявилась в рассматриваемом районе и была связана с предкелловейской фазой складчатости. Ключевые слова: полиметаллическое и золото-сульфидно-кварцевое с ЭПГ оруденение; металлогеническая зона; золото-платиновый черносланцевый тип оруденения, Северный Кавказ. Recently, in the fi eld of Geology of gold deposits, a fundamental problem is to identify the nature and causes of platinum and palladium - bearing gold deposits established for a number of fi elds in the Far East, Chukotka, North-East Asia, the Urals, and the Tien Shan. Central Russia (ferruginous quartzites of the giant reserves of the KMA and BMA deposits), and in the last 15 years, the North Caucasus, where Au-Pt-Pd mineralization associated with the Devonian black shale was detected. In 2018, we have identifi ed a new source of noble metal (Au-Pt-Pd) mineralization, associated with the early-medium-Jurassic black slates in the territory of Mountain Ossetia. The article provides information about the evolution of metal genetics in this part of the North Caucasus in the Kimmeria era. The main results of the search for gold-silver and gold-sulfi de types of mineralization in Mountain Ossetia, conducted by JSC “Sevosegologorazvedka” and JSC “North-Caucasian PGO" within the Kakadur-Lamardon ore zone, which is part of the Avsandur-Lamardon ore fi eld, are presented. It was conducted that the Toar-Aalen carbon-terrigenous fl isoid (black-shale) strata, which holds the Kakadur-Hanikom and Kadat-Hampaladag polymetallic core deposits, as well as perspective ore bodies with vein and stockwork goldcontaining lead-zinc and gold-sulphide-quartz types of mineralization, has increased (for S, Fe2O3, Cr, Ni, Cu, Zn, As, Zr, Pb, Sb, Rb, Ag, Au, Pd, Pt, Ru) metal content. A comprehensive analysis of the obtained data suggests that convection was the main mechanism for the formation of noble metal mineralization. The" trigger " for its launch could be zones of active faults, dissimilar movements which led, due to friction, to the heating of black shale stratum.As a result, there was a convection of heated in tectonically active zones vadose waters, located in the black shale strata, and their movement to the front part of the emerging hydrothermal-metasomatic column. This tectonic activity was observed in the studied area and was associated with the pre-Kelleway phase of folding Keywords: polymetallic and gold-sulfi de-quartz mineralization with EPG; metallogenic zone; gold_platinous blackshale type of mineralization, North Caucasus

The location and Potential Assessment of the Ore Regions in the South-Western Part of the Koryak Highland

Актуальность рассматриваемой темы в том, что орогенные пояса материковой части Камчатского края насыщены полезными ископаемыми, приуроченных к поясам, образованным последовательным приростом окраин континента от древних с северо-запада к юго-востоку. Такими поясами с месторождениями Ag, Au, Sn, Hg, S являются Северо-Западно-Корякский олигоценовый и Южно-Корякский миоценовый, образованные на северной и южной границе Центрально-Корякской окраины позднемелового континента. Они сформированы в олигоцене и миоцене изолированными вулканогенами локальных андезитовых полей, прорванных гранитоидами тектонической активизации. С ними связаны рудные площади, локализация которых позволит обеспечить прирост запасов разрабатываемых россыпей платиноидов. Цель работы заключается в установлении тектонических закономерностей образования вулканогенов, связанных с ними рудных районов и получения новых данных по их прогнозу. В Северо-Западном поясе оформилась металлогеническая зона с Уннэйваямским, Гайчаваямским и Пальматкинским районами, сопряжёнными с одноименными вулканогенами, в Южно-Камчатском с Ветроваямским вулканогеном. Методология и методы исследования. Методология заключена в глыбово-клавишной структуре литосферы и её земной коры на активных окраинах континента. Методика основана на установлении системной связи структурных элементов геолого-геофизической системы тектоника-вулканогены . Результаты работ и их анализ. Предложена схема закономерностей размещения известных и прогнозируемых рудных районов, узлов юго-запада Корякского нагорья. Они обусловлены глыбово-клавишной тектоникой и локализованы в звеньях серии продольных субпараллельных разновозрастных региональных структур СВ простирания, последовательно наращивающих континент к юго-востоку. Звенья являются дискретными и определяют размеры рудных районов. Рассмотрены выделяемые звенья Северо-Западно-Корякского олигоценового и Южно-Корякского миоценового поясов. В первом СЗ поперечными межглыбовыми разломами литосферы образованы вулканогены гнездового типа. Они возникли на пересечении фундамента позднего мела и южной окраины сопредельной Пенжинской СФЗ поперечными межглыбовыми разломами. В пересечениях образуется литосферный столб вещества гранитоидной активизации верхней мантии и позднемелового осадочного разреза фундамента. Делается вывод, что в Южно-Корякском поясе вулканоген является линейным, образованным заключением линейного СВ Ветроваямского выступа фундамента и чехла между двумя поперечными межглыбовыми разломами. В нём рудоносными вторичными кварцитами создан Ильпинский рудный район с крупными месторождениями самородной серы с Ag, Au, Hg, S. Орогенный вулканизм на активных окраинах континентов сопряжён с основными элементами тектоники и магматизма, создавшими условия образования минерагенических таксонов. На примерах орогенных поясов олигоцена и миоцена очевидна роль геотектонических и металлогенических аспектов авторской методологии глыбово-клавишной структуры литосферы активных окраин. Она эффективна в прогнозе рудных площадей и их оценке последующими геологоразведочными работами. The relevance of the work is that the orogenic belts of the mainland of the Kamchatka Territory are saturated with minerals confined to the belts formed by the successive growth of the continental margins from the ancient ones from the north-west to the south-east. Such belts with deposits of Ag, Au, Sn, Hg, S are the Northwest Koryak Oligocene and South Koryak Miocene, formed on the northern and southern borders of the Central Koryak margin of the Late Cretaceous continent. They are formed in the Oligocene and Miocene by isolated volcanogens of local andesitic fields, broken by granitoids of tectonic activation. Ore areas are associated with them, the localization of which will ensure an increase in the reserves of developed placer deposits. The purpose of the work is to establish tectonic patterns of formation of volcanogens, associated ore regions and obtain new data on their forecast. In the North-Western zone, a metallogenic zone took shape with the Unneivayamsky, Gaichavayamsky and Palmatkinsky regions, associated with the same named volcanogenes, in the South Kamchatka - with the Vetrovayamsky volcanogen. Methodology and research methods. The methodology lies in the block-key structure of the lithosphere and its earths crust on the active margins of the continent. The methodology is based on establishing a systemic connection between the structural elements of the geological and geophysical system tectonics-volcanogens. The results of the work and their analysis. A scheme of patterns of distribution of known and predicted ore regions, nodes of the south-west of the Koryak upland is proposed. They are caused by block-key tectonics and are localized in the links of a series of longitudinal subparallel regionally different age structures of NE strike, successively expanding the continent to the southeast. The links are discrete and determine the size of the ore regions. The distinguished links of the Northwest Koryak Oligocene and South Koryak Miocene belts are considered. In the first northwestern region, nesting volcanogens are formed by transverse interblock faults of the lithosphere. They arose at the intersection of the Late Cretaceous foundation and the southern edge of the adjacent Penzhinsk structural-facial zone with transverse interblock faults. At the intersections, a lithospheric column of granitoid activation matter of the upper mantle and the Late Cretaceous sedimentary section of the basement is formed. It is concluded that the volcanogen in the South Koryak belt, has a linear nature, formed by the conclusion of a linear NE of Vetrovayamsk ledge of the basement and cover between two transverse interblock faults. There ore-bearing secondary quartzites created the Ilpinsk ore region with large deposits of native sulfur with Ag, Au, Hg, S. The orogenic volcanism on the active margins of the continents is associated with the basic elements of tectonics and magmatism, which created the conditions for the formation of minerogenic taxons. The role of geotectonic and metallogenic aspects of the authors methodology of the block-key structure of the active lithosphere margins is evident on the examples of the orogenic Oligocene and Miocene belts. It is effective in forecasting ore areas and evaluating them with subsequent exploration works

Mineralogical and geochemical features of bismuth in Proterozoic ore-bearing structures of west part of the Ingul megablok (Ukrainian shield)

In this paper we summarize the geological information about regional distribution features of bismuth in the Ingul megablok of Ukrainian shield. Different Proterozoic ore sites situated within the Bratsk-Zvenihorodka and the Ingul-Tyasmyn metallogenic zone are considered. They are characterized by the presence of various scale deposits of uranium, rare metals (Li, Rb, Cs, Ta, Nb, W, Sn) and precious metals (Au, Ag). Minerals-concentrators of bismuth and main paragenetic associations comprising native Bi, tellurides, bismutite, maldonite, wittichenite, parkerite, matildite are investigated. It should be noted that within the intrusions of the Korsun-Novomyrgorod pluto and the Novoukraika massif, which spatially separate the Bratsk-Zvenihorodka and the Ingul-Tyasmyn metallogenic zone, there are also deposits of uranium and titanium, but bismuth is practically absent. At a relatively low content (from 5 to 60 g / t) bismuth is a typical metal for ore objects of K-U formation and rare metal pegmatites of Polokhiv and Stankuvatske ore fields. For the first time, mineral forms of bismuth (native bismuth, Pb-bismuth, galenobismuthin) were determined in the Obginnyi ore occurence, where abnormally high content values of bismuth up to 0,8-1,3%. The geochemical feature of numerous gold ore objects is the almost complete dominance of bismuth compounds with tellurium. There are headleite (Ві7Те3), telluric bismuthite (Ві2Те3), tsumoit (ВіТе), pilsenite (Ві4Те3), joseite-B (Bi4(S,Te)3) detected individualized phases in the Bi-Te system. In the skarns of the Bandurkivsky ore occurence the early productive association consists of maldonite + joseite-B + tetradimite, and the late one consists of native gold + bismuth. Bismuth sulfosalts are present in various ore objects as part of sulfide Cu-Ag-Bi and Pb-Ag-Bi mineralization. The study of geochemistry and mineralogy of bismuth was performed in M.P. Semenenko institute of geochemistry, mineralogy and ore formation of NAS of Ukraine, using a scanning electron microscope JSM-6700F (JEOL). Data on the chemical composition of minerals were obtained using microprobe devices JCXA-733, JXA-8200 (Technical Center of the National Academy of Sciences of Ukraine) and Cameca SX-100 (Technical University, Klausstal (Germany)). The data of spectral and atomic absorption analysis of the central laboratory of KP «Kirovgeologiya» were also used in writing the article.

Age, composition and sources of rocks and ores of the Okunevskoe fluorite-leucophanite deposit, Western Sayan: assessment of the contribution of magmatism to ore mineralization

The paper presents data on the structure of the Okunevskoe fluorite-Leucophanite deposit, located within the Early Paleozoic rare-metal East Sayan rare metal metallogenic zone. The deposit is controlled by alkali granitoids, with ore mineralization concentrated at the contact of granitoids and host carbonates. It is represented by leucophanite-fluorite and pyroxene-fluorite ore types. The Ar-Ar age of granitoids is established at ~485Ma. Geochemical characteristics of igneous rocks, ores, and host carbonates are determined. It is shown that in geochemical parameters leucophanite-fluorite ores are close to alkaline granites, while pyroxene-fluorite ores are close to alkaline syenites. The characteristics of the Nd isotop composition in rocks and ores of the deposit are given. Igneous rocks (granitoids and basite dikes) are characterized byNd (t) values from +4 to +5.5. TheNd (t) values in ores range from +1.2 to+4.2, in skarns itis +4.8. The host carbonates have abruptly contrasting valuesNd (t) = 4.2. Based on these data, which demonstrate a high compositional similarity between granitoids and ores, aconclusion is drawn about the leading contribution from magmatic processes to the ore mineralization of the Okunevskoe deposit.