Mo–Cu and Au–Ag–Pb–Zn ore occurrences of the Upper-Myaundzha ore cluster, located among Jurassic terrigenous complexes of Inyali–Debin turbidite terrane of the Yana–Kolyma Orogenic Belt have been studied. The Speshnoe Mo–Cu occurrence is a quartz-sulfide stockwork, hosted by porphyry quartz syenite with U–Pb age of 84 Ma. The Spyashchee Au–Ag–Pb–Zn ore occurrence represents a series of carbonate-quartz veins and mineralized zones in Jurassic sedimentary rocks. The geochemical spectrum of stockwork mineralization is Mo–Au–Ag–Co–Cu–(As, W); that of vein-veinlet mineralization is Pb–Ag–Sb–Au–As–Zn–Bi. The Upper Myaundzha ore cluster, located in the central segment of the Yana–Kolyma orogenic belt, is a porphyry-epithermal system, including hypabyssal syenite-monzonite stock, Mo–Cu sulfide-quartz stockwork, and subepithermal Au–Ag–Pb–Zn veinlets. The age of the system coincides with the formation age of the secondary stage of the Okhotsk–Chukotka volcanic belt.

Porphyry copper mineralization of various Mesozoic volcano-plutonic belts of Northeastern Asia exhibits both the similarities and differences. There are no significant differences in the composition of granitoids of porphyry copper systems of the different belts. Isotope-geochemical characteristics of the mineralization are contrasting. Objects of the Okhotsk-Chukotka and Oloi belts are characterized by a near-zero isotopic composition of the sulfide sulfur, which corresponds to a magmatic source. Isotopically heavier sulfur of mineralization of the Uyanda-Yasachnaya belt indicates borrowing the ore material from the hosting sedimentary-metamorphic sequences. Data on the ore lead isotopic composition indicate lower crustal sources of the Oloi belt and upper crustal ones of the Uyanda-Yasachnaya belt. The Okhotsk-Chukchi belt is characterized by heterogeneity of the sources of the mineral matter.

The Talnikovoye ore field where previous academic research and exploration work revealed porphyry copper mineralization is described. Our data show that mineralization is confined to the intrusions of Turonian granodiorite and quartz diorite (91 Ma, U-Pb metohod), as well as the accompanying hydrothermal-explosive breccias. Biotite-epidote-chlorite propylites are widespread within the ore field; in the southern part, phyllic alteration is superimposed on the halo of K-feldspar alteration. The ore occurs in zones of intense quartz, chlorite-epidote-quartz (with chalcopyrite and molybdenite), sulfide-potassium feldspar-quartz (with chalcopyrite and bornite), and sulfide-quartz-sericite (with chalcopyrite) stockwork veining with copper-molybdenum mineralization. They are characterized by moderate concentrations of Cu (0.1–0.3 %, reaching 1.1 %) and Mo (up to 0.1 %), low concentrations of Au (up to 0.1 g/t) and Ag (up to 2.6 g/t) and have a Cu-Mo-(Au, Ag, Pb, Zn, Sb, As) geochemical signature. Fluid inclusion data suggest the formation of mineralized veinlet quartz during the magmatic-hydrothermal transition (430–150 °С) with solutions at high (50 wt % NaCl equiv.), medium and low concentration (5–18.9 wt % NaCl equiv.) involved under the cooling-dilution scenario. Values of the main geochemical indicators, such as Cu/Mo (30–60) and Cu/Au (> 1 × 105) ratios allowed us to assign the Tal’nikovoye ore field to the porphyry copper-molybdenum type characteristic of continental-margin volcano-plutonic belts formed at the mafic island-arc basement. The geochemical parameters of porphyry granitoids indicate their formation in a setting of subduction-to-transform plate boundary transition.

Охарактеризовано Мяучанское рудное поле, расположенное в пределах Омсукчанской зоны Охотско-Чукотского вулканогенного пояса. Составляющие рудное поле Ag-Pb-Zn рудопроявления Коренное и Малютка локализованы в центральной части антиклинальной складки северо-западного простирания, сложенной верхнетриасовыми карбонатно-терригенными толщами, прорванными штокообразными телами и дайками позднемеловых андезитов, монцодиоритов, гранит-порфиров и риолитов. Сульфидно-карбонат-флюорит-кварцевые жилы и жильно-прожилковые зоны с арсенопиритом, пиритом, сфалеритом, галенитом, халькопиритом, Ag-тетраэдритом распространены как в интрузиях, так и в терригенных толщах. Геохимический спектр минерализации As-Sb-Ag-Pb-Au-Bi-Cu-Zn-W. Результаты изучения флюидных включений наряду с данными по распределению редкоземельных и рудных элементов указывают на формирование руд в эпитермальной обстановке гидротермально-магматической системы из хлоридных растворов с участием поверхностных вод. Отложение руд происходило в диапазоне температур 106—287 °С из растворов соленостью от 0.5 до 9.0 мас. % NaCl-экв. Руды, содержащие Ag порядка 70 г/т и Pb до 1.2 %, формировались в условиях выкипания из растворов, обогащенных солями Fe; руды с содержанием Ag менее 7 г/т, а Pb до 25 г/т образовались в условиях разбавления из гидротерм, в составе которых преобладали соли Na с незначительной примесью K. Минерализация Мяучанского рудного поля представляет верхний уровень Ag-Pb-Zn рудной системы, аналогичной месторождению Гольцовое. The Myauchan ore field located in the Omsukchan zone of the Okhotsk–Chukotka Volcanic Belt is des­cri­bed. The Korennoe and Malyutka Ag–Pb–Zn ore occurrences forming this field are localized at the center of anticlinal fold of NW strike made up of Upper Triassic carbonate-terrigenous deposits intruded by stock-like bodies and dikes of Upper Cretaceous andesite, monzodiorite, granite-porphyry, and rhyolite-porphyry. Sulfide–carbonate–fluorite–quartz veins and vein–veinlet zones with arsenopyrite, pyrite, sphalerite, galena, chalcopyrite, and Ag-tetrahedrite are localized both in intrusions and in terrigenous strata. The field bears As–Sb–Ag–Pb–Au–Bi–Cu–Zn–W mineralization. Study of fluid inclusions and REE and ore element patterns show that the field ores formed from chloride solutions with the participation of surface waters in hydrothermal-magmatic system under epithermal conditions. The ores were deposited from solutions with TDS = 0.5–9.0 wt.% NaCl equiv. in the temperature range 106–287 ºC. The ores containing ca. 70 ppm Ag and up to 1.2% Pb formed through boiling-off of solutions enriched in iron salts. The ores with Ag < 7 ppm and Pb ≤ 25 ppm were generated from diluted hydrothermal solutions with predominant sodium salts and potassium admixture. Mineralization of the Myauchan ore field marks the upper level of the Ag–Pb–Zn ore system similar to the Gol’tsovoe deposit.

Copper mineralization in the Magadan region (North-East of Russia) has been established in quartz-chloritoid and chlorite shales of the middle and upper Riphean of the Prikolymsky terrane. Compared to the upper crust, copper shales of the Oroek deposit are noticeably enriched in a narrow range of trace elements: Cu, Ag, Au, Rh, and Se, with enrichment factors ranging from 10-fold (Se, Rh) to 100-fold (Ag, Au) and even 1000-fold (Cu) suggesting, apparently, their synchronous involvement in ore formation. In addition, the studied samples are slightly enriched in Cd, Li, Co, Zn, V, U, Sc, Y, and REE. Copper shales show relatively flat rare earth element (REE) patterns similar to the chondrite-normalized pattern having no distinct positive or negative Eu anomalies and dominated by light lanthanides. The Ce/Ce* and Eu/Eu* values indicate that ore formation proceeded under oxidizing conditions. The obtained geochemical data show that the Riphean host rocks could serve as a source of trace elements and REE ore-forming fluids. In the ores, covellin and chalcocite are the main copper minerals; less common are roxbyite, idaite, nukundamite, spioncopite, chalcopyrite, silver-bearing (Ag about 1 wt. %) bornite and yarrovite, as well as native gold. Fluid inclusions in quartz suggest that copper mineralization was formed at temperatures of 212–190 °C and a pressure of 1 kbar, from hydrothermal solutions of medium salinity (from 13.8 to 12.4 wt. % eq. NaCl) and high density (0.95–0.98 g/cm3) saturated with chlorides of Ca, Mg, and K. The copper shales of the Prikolymsky terrane differ from sedimentary copper and copper shales of the African Belt by low Co and Ni contents and from the Kupfershifer by low concentrations of Pb and Zn. The obtained results can be used for prognosticating new deposits.

In the present study, we carried out molybdenite Re-Os, zircon U-Pb dating on granitoids from the insufficiently explored Cu-Mo and Mo porphyry deposites and ore occurrences (Osennee, Oksinskoe, Uptar, Doroninskoe) of the Magadan region. The ore-age of these porphyry objects is confirmed by Re-Os dating of molybdenite and corresponds to the age of the ore-forming granitoids. Intrusive complexes (Svetlinsky and Magadansky), which related to Mo mineralization, have a variable SiO2 content of 61-74 %, and K2O Na2O content of 5,4-6,9%. They are calc-alkaline series (K2O/Na2O ratio of 0,6-0,8) I type granitoids. They are depleted high-field-strength elements Nb and Ta (HFSE) and enriched Rb, Sr, Hf (LILEs). On the Sr/Y – Y variation diagram, most of the granitoids are located in the field of «adakite» igneous rocks of porphyry deposits. The U-Pb age of granite zircons was determined by the SHRIMP method and showed two pulses of Albian-Cenomanian magmatic activity– a 93-95 Ma (Svetlinsky complex) and a 102-103 Ma (Magadansky complex). The isochronous molybdenum Re-Os age 99-100 Ma and 92-94 Ma from Doroninsky Mo-porphyry stock and from Osennee and Usinskoe Cu-Mo ore occurrences confirms the genetic relationship of granites and Mo mineralization. There is a little age gap between granite cristallisation and ore formation. Mo mineralization probadly was formed later by 1-2 Ma from the magmatism responsible intrusion. The isotopes Re and Os are used to determine the origin of the source of porphyry mineralization metals. High Re contents (>33 ppm) in studied molybdenite indicates mantles course of metall in deposites Magadan mineragenic area. The mantle source is indicated by low non-radiogenic ratios of 187Os/188Os (0.32-0.21) in molybdenite of the Usinskoe ore occurrences. A more radiogenic osmium (187Os/188Os =1-15) was obtained for the Osennee ore occurrence. New precision geochronological data on the Albian-Cenomanian age of Cu-Mo mineralization allow us to conclude about geodynamic environments that controlled ore formation. Obviously, mineralization in Magadan mineragenic area spatially and temporally related with Albian-Cenomanian igneous rocks and have identical sourses. Ore-forming granitoids are part of the Albian-Cenomanian orogenic magmatic belt, which occurred in a sliding plate boundaries environment on the border of the Eurasian continent margin and the Palaeo-Pacific Ocean (Khanchuk, 2019).

We have studied the mineral composition of ores from the Pepenveem epithermal Au-Ag deposit, which is a promising new object of the Chukchi Peninsula. It has been found that the ore formation process was developed in the following sequence: Pyrite, arsenopyrite, and marcasite were deposited at the early stage, next were Pb, Zn, and Cu sulfides; at the late stage, native gold, pyrargyrite, stephanite, proustite, minerals of the pearceite-polybasite series, acanthite, and other Ag minerals were deposited. The results of fluid inclusion studies indicate that the Au-Ag mineralization formed from low-temperature (236-137 degrees C) low-concentration chloride hydrotherms (0.18-1.57 wt.% NaCl eq.). The results of calculation of thermodynamic equilibria have shown that in the temperature range from 200 to 100 degrees C, there were a decrease in the fugacity of sulfur (lg f(S2) from -10 to -21) and oxygen (lg f(O2) from <-36 to <-48) and a change from near-neutral to acidic solutions. Compared to other Au-Ag deposits on the Chukchi Peninsula (Corrida and Valunistoe), which are characterized by wide distribution of Se-and Te-bearing Au-Ag chalcogenides (naumannite, cervelleite, and hessite), ore formation with gold-silver-sulfosalt mineralization at the Pepenveem deposit took place at lower temperatures and lower selenium, tellurium, and oxygen fugacity. The data obtained permit us to refer the Pepenveem deposit to the group of epithermal low-sulfidation (LS) deposits.

Numerous epithermal Au–Ag deposits and ore occurrences of the Chukchi Peninsula are localized in the Cretaceous Okhotsk–Chukotka (OCVB) continent-marginal and Late Jurassic–Early Cretaceous Oloi (OVB) island arc volcanic belts and in Early Cretaceous postcollisional volcanic troughs. Volcanotectonic depressions, calderas, and volcanic domes control the location of the deposits. The orebodies of the deposits are quartz–adularia veins, sometimes en-echelon ones forming extending vein zones, as well as isometric and linear stockworks. The auriferous veins of most deposits display complex breccia–crustification structures. The vein ores have rhythmically and colloform–banded structures, with a predominantly fine distribution of ore mineral grains, often with banded clusters of ore minerals (ginguro). Native gold is of low fineness; the dispersion of this index varies from low to high. Acanthite is widespread in the ores. Its highest contents are specific to deposits with the repeated redistribution of substance (Kupol, Corrida, and Valunistoe). Based on the results of mineralogical studies, most of the epithermal Au–Ag deposits of the Chukchi Peninsula can be assigned to the Se type. The ores of some deposits (Valunistoe, Dvoinoe, etc.) contain both Se and Te minerals. The telluride-richest sites of the Sentyabr’skoe and Televeem deposits are far from the main orebodies. Most of the Chukchi epithermal Au–Ag deposits have many common characteristics (low and moderate temperatures of fluids, low fluid salinity, domination of carbon dioxide over methane, etc.) typical of low-sulfidation deposits. The maximum temperatures and salinity are specific to fluids in the Central Chukchi sector of the OCVB and in the Baimka zone of the OVB, and the minimum ones are typical of fluids in the East Chukchi flank zone and inner zone of the OCVB. The average salinity of mineral-forming fluids in the inner zone of the OCVB is half as high as the salinity of fluids in the East Chukchi flank zone of this belt, although the sulfate content is higher. At the same time, the fluids in the inner zone of the OCVB are richer in carbon dioxide and bicarbonate ion than the fluids in the East Chukchi flank zone of this belt. The fluid inclusion data permit the Vesennee deposit (Baimka zone) to be regarded as an intermediate-sulfidation one and suggest the presence of epithermal high-sulfidation deposits in the inner zone of the OCVB.

The authors briefly characterize the geology and structure of the Shtokovoye ore field attached to the area where the Khurchan-Orotukan zone of tectonic-magmatic activation overlays the structures of the Yana-Kolyma ore-bearing belt. Studied are mineral associations and physicochemical conditions of gold ore bodies, located both in granites and in hornfelsed sedimentary masses. By the main features of its geological structure, ore composition, and physicochemical formation conditions, the Shtokovoye ore field mineralization corresponds to the "depth" group of the gold-rare-metal formation, analogous to the Butarnoye, Basugunyinskiye, Dubach, and Nadezhda occurrences. Its ores are peculiar in the late epithermal mineralization, which is associated with the Okhotsk-Chukotka volcanic belt and overlays the sinaccretional gold-rare-metal mineralization.

The mineral and chemical compositions of ores from the Corrida epithermal Au-Ag deposit (Chukchi Peninsula, Russia) were studied using the optical and scanning electron microscopy with X-ray energy-dispersion microanalysis. The deposit was formed at the time close to the period when the basic volume of acid magmas had been emplaced within the Okhotsk–Chukotka belt (84 to 80 Ma). The Au–Ag mineralization is distinguished with Au-Ag sulphides and selenides (uytenbogaardtite-fischesserite solid solution, Se-acanthite, S-naumannite) and Ag halides of the chlorargyrite-embolite-bromargyrite series. The ores were formed in two stages. Using microthermometric methods, it has been established that the ore-bearing quartz was formed in the medium-temperature environment (340–160 °C) with the participation of low-salt (3.55 to 0.18 wt.% NaCl eq.) hydrotherms, mostly of the NaCl composition with magnesium, iron and low-density СО2. According to our results of thermodynamic modeling at temperatures from 300 to 25 °C and data on mineral metasomatic alterations of the host rocks, the Au-Ag-S-Se-Cl-Br mineralization was formed at decreasing temperature and fugacity of sulphur (logƒS2 from −6 to −27), selenium (logƒSe2 from −14 to −35), and oxygen (logƒО2 from −36 to −62), with near-neutral solutions replaced by acid solutions. Analysis of the obtained data shows that the Corrida refers to the group of the LS-type epithermal deposits. This deposit is a new example of epithermal deposits with significant quantities of Au–Ag chalcogenides (acanthite, uytenbogaardtite, fischesserite, naumannite and others).

The Burgali deposit is located in the Paleozoic Kedon volcanic belt (KVB) within the Omolon cratonic terrane. The orebodies of the Burgali deposit are veined and stockwork-type. The studies of the wallrock metasomatites demonstrate that the erosional truncation of the deposit is close to minimal. The ores of the deposit are enriched in the chalcophile elements (Au, Ag, As, Sb, Te, W, Mo, and Bi) and poor in the rare earths. The rare-earth element (REE) spectra are dominated by light lanthanides. The ores are characterized as very low-sulfidation with finely disseminated mineralization, widespread occurrence of chalcedony, and widespread colloform-banded, often combined with brecciated, structures. The late quartz veins contain Lower Carboniferous coaly siltstone fragments, filled with petrified timber remains, which indicate the Carboniferous age of the ore mineralization. The ores contain widespread Au- and Te-bearing pearceite and rare minerals such as argyrodite and the selenous petrovskaite and uytenbogaardtite. The data obtained enable the Burgali deposit to be classified as low-sulfidation epithermal. The outlook for Ag and Au reserve additions is based on the further studies and exploration of the ore-bearing stockwork.

Исследован минеральный состав руд эпитермального Au-Ag месторождения Пепенвеем, которое представляет собой новый перспективный промышленный объект Чукотского полуострова. Установлено, что процесс рудоотложения развивался в следующей последовательности: на ранней стадии отлагались пирит, арсенопирит, марказит, далее сульфиды Pb, Zn и Cu; в завершении произошло отложение самородного золота, пираргирита, стефанита, прустита, минералов пирсеитполибазитового ряда, акантита и других минералов Ag. По результатам термобарогеохимических исследований Au-Ag минерализация месторождения формировалась из низкотемпературных (236– 137oС), низко концентрированных хлоридных растворов (1.57–0.18 мас. % экв. NaCl). Согласно результатам расчетов термодинамических равновесий в интервале температур от 200 до 100°C происходило снижение фугитивностей серы (log ƒS2 от -10 до -21) и кислорода (log ƒО2 от < -36 до < -48), а также смена близнейтральных растворов на кислые. По сравнению с другими Au-Ag месторождениями Чукотки (Коррида, Валунистое), для которых характерно широкое распространение халькогенидов золота и серебра с Se и Te (науманнита, кервеллеита, гессита), рудоотложение на Пепенвееме происходило при более низких температурах и фугитивностях селена, теллура и кислорода, что привело к образованию золото-серебро-сульфосольной рудной минерализации. Проведенные исследования позволяют отнести Пепенвеем к золотосеребряным эпитермальным месторождениям адуляр-серицит-кварцевого типа (по международной классификации low-sulfidation).

Многочисленные эпитермальные Au-Ag месторождения и рудопроявления на территории Чукотского полуострова принадлежат меловому, окраинно-континентальному Охотско-Чукотскому (ОЧВП) и позднеюрско-раннемеловому, островодужному Олойскому (ОВП) вулканическим поясам, а также постколизионным, раннемеловым вулканическим впадинам. Вулканотектонические депрессии, кальдеры и вулканические купола контролируют размещение месторождений. Рудные тела месторождений представлены кварц-адуляровыми жилами, иногда собранными кулисообразно в протяженные жильные зоны, а также изометричными и линейными штокверковыми залежами. Для рудоносных жил большинства месторождений характерны сложные, комбинационные брекчиево-крустификационные текстуры. В жильных рудах широко развиты ритмичнои колломорфно-полосчатая текстуры, обладающие преимущественно тонким характером распределения рудных вкрапленников, нередко с полосчатыми скоплениями рудных минералов (гингуро). Самородное золото имеет относительно низкую пробность и дисперсию этого показателя от низкой до высокой. Акантит широко распространенный минерал в рудах. Наиболее высокие его концентрации характерны для месторождений с многократным перераспределением вещества (Купол, Коррида, Валунистое). В результате минералогических исследований большинство эпитермальных Au-Ag месторождений Чукотки можно отнести к Seтипу. На ряде месторождений (Валунистое, Двойное и др.) в рудах присутствуют, как селен-, так и теллур-содержащие минералы. Наиболее обогащенные теллуридами участки месторождений Сентябрьское и Телевеем находятся на удалении от основных рудных тел. Большинство эпитермальных Au-Ag месторождений Чукотки имеют много общих черт (низкие и средние температуры, низкая соленость флюида, преобладание углекислоты над метаном и др.), типичных для низкосульфидизированного класса. Максимальные величины температур и соленостей характерны для флюидов из Центрально-Чукотского сектора ОЧВП и Баимской зоны ОВП, а минимальные – для флюидов Восточно-Чукотской фланговой зоны и внутренней зоны ОЧВП. Соленость минералообразующих флюидов внутренней зоны ОЧВП в среднем вдвое меньше, чем флюидов Восточно-Чукотской фланговой зоны ОЧВП, а содержания сульфатов выше. В то же время флюиды внутренней зоны ОЧВП богаче углекислотой и бикарбонат-ионом относительно флюидов Восточно-Чукотской фланговой зоны ОЧВП. Термобарогеохимические данные позволяют месторождение Весеннее (Баимская зона) отнести к среднесульфидизированному классу и прогнозировать во внутренней зоне ОЧВП открытие высокосульфидизированных эпитермальных месторождений.

крупнейшие и хорошо изученные Cu-Mo-порфировые ме-Cu-Mo-порфировые ме--Mo-порфировые ме-Mo-порфировые ме--порфировые месторождения сконцентрированы в Андийском окраинно-континентальном поясе (чили), в эоцен-олигоценовой истории развития которого установлены эпизоды интенсивных деформаций, кристаллического сжатия

The potentially large Primorskoe epithermal Au-Ag deposit is represented by three areas: the Kholodnyi, Spiridonych, and Teplyi. It is located in the Omsukchan district of Magadan oblast, where mining is carried out at the largely similar Dukat, Lunnoe, Gol’tsovoe, Arylakh, Tidit, Pereval’noe, and other deposits. The deposit under review is located in the Kalalaga volcano-tectonic depression, where ore has been emplaced in a gently dipping sequence of Late Cretaceous ignimbrites and rhyolites more than 700 m in thickness crosscut by numerous intermediate and mafic dykes. According to drilling data, there is a leucocratic granite massif 400–500 m beneath the deposit, which is exposed on the surface in the northeastern part of the ore field. The presence of Bi-bearing galena and matildite, as well as medium- to high-temperature metasomatic facies (epidote and actinolite) and the specific physicochemical conditions of epithermal Ag-Au ore emplacement, attests to the above-intrusion position and the role of granitoids as high-temperature magmatic fluid generators responsible for supplying Bi and heating the host rock. The ore chemistry is quite consistent with its mineral composition. High Mn and Ag; elevated Au; low Cu, Pb, Zn, Sb, As, Bi, and Te; and low total REE concentrations were established, along with negative Eu and positive Ce anomalies. The high Te/Se, Sr/Ba, Y/Ho, and U/Th ratios in the ores are due to their location in the area influenced by the granitoid pluton. The physicochemical parameters of ore emplacement in the Teplyi area are unusual: high temperatures, low salt concentrations, and fluid densities typical of a “dry vapor” environment. The obtained data allow the Primorskoe to be classified as an intermediate sulfidation epithermal deposit. The data discussed below are of practical use for regional metallogenic forecasting, exploration, and economic assessment of epithermal Ag-Au deposits.

Потенциально крупное Ag-Au эпитермальное месторождение Приморское представлено тремя участками Холодный, Спиридоныч и Теплый. Оно расположено в Омсукчанском округе Магаданской области, где разрабатываются во многом аналогичные месторождения: Дукат, Лунное, Гольцовое, Арылах, Тидит, Перевальное и др. Месторождение приурочено к Калалагинской вулкано-тектонической депрессии и локализовано в пологозалегающей толще позднемеловых игнимбритов и риолитов мощностью более 700 м, которая прорвана многочисленными дайками среднего и основного состава. Массив лейкократовых гранитов, по данным бурения, находится под месторождением на глубине 400–500 м и выходит на поверхность в северо-восточной части рудного поля. Присутствие Bi-содержащего галенита и матильдита, наличие средне-высокотемпературных фаций метасоматитов (эпидот, актинолит) и специфические физико-химические условия образования эпитермальных Ag-Au руд свидетельствуют о надинтрузивном положении и роли гранитоидов, как генераторов высокотемпературных магматических флюидов, осуществлявших привнос Bi и прогрев вмещающих оруденение пород. Геохимические особенности руд хорошо согласуются с их минеральным составом. Установлены высокие концентрации Mn и Ag, повышенные — Au, низкие — Cu, Pb, Zn, Sb, As, Bi и Te, низкая сумма РЗЭ, отрицательные Eu- и положительные Се-аномалии. Высокие значения показателей Te/Se, Sr/Ba, Y/Ho и U/Th в рудах связаны с положением месторождения в зоне влияния гранитоидного массива. Физико-химические параметры образования руд участка Тёплый необычны — характеризуются высокими температурами, низкими концентрациями солей и плотности флюида, что характерно для “сухого пара”. Полученные результаты позволяют отнести эпитермальное месторождение Приморское к промежуточному классу. Приведенная в статье информация имеет практическое значение для региональных прогнозно-металлогенических построений, поисков и оценки эпитермальных Ag-Au месторождений.

The paper presents the res�lts of the U-Pb SHRIMP dating of zircons (86-84±1 Ma) from the Nayakhan complex granitoides of Korkodon-Nayakhan zone of the Okhotsk-Ch�kotka volcano-pl�tonic belt (OCVB) and Re-Os dating of molybdenite (84.6±0.5 Ma) from molybden�m-porphyry ores, spatially associated with the small diorite bodies.The data obtained along with the res�lts of the mineralogical and thermobarogeochemical analyzes of ores indicate genetic relationship of porphyry mineralization and the OCVB s�pra-s�bd�ction granitoid magmatism, c�ring inherited zone of disr�ption and extension in Late Cretaceo�s.

As a potentially large Ag-Au epithermal deposit, Primorskoye comprises the following three areas: Kholodny, Spiridonych, and Teply. This deposit is located in the Omsukchan district of the Magadan Region, where similar deposits, including Dukat, Lunnoye, Goltsovoye, Arylakh, Tidit, and Perevalnoye, have developed. The deposit can be attributed to the Kalalagian volcano-tectonic depression and is localized in a flat-lying rock mass in the Late Cretaceous ignimbrites and rhyolites having thicknesses of greater than 700 m, which is cut through by numerous dykes of medium and major composition. According to the drilling data, the solid mass of leucocratic granites is located in deposits at a depth of 400–500 m with outcrops in the northeastern part of the ore field. The presence of Bi-containing galena and matildite, the availability of mid and high temperature facies of metasomatites (epidote and actinolite), and the specific physical and chemical conditions during the formation of the epithermal Ag-Au ores indicate the intrusive position above and the role of granitoids as generators of high temperature magmatic fluids, which introduced Bi and heated the rocks enclosing the mineralization. The geochemical features of the ores are well correlated with their mineral compositions. The high concentrations of Mn and Ag, elevated concentration of Au, low concentrations of Cu, Pb, Zn, Sb, As, Bi, and Te, low sum of REE, and negative Eu- and positive Се-anomalies were observed. The high values of the Te/Se, Sr/Ba, Y/Ho, and U/Th indicators in the ores are associated with the deposit location in the zone of granitoid massif effect. Further, the physical and chemical parameters of ore formation in the Teply area are unusual and are characterized by high temperatures, low concentrations of salts, and fluid density, which are indicative of the typical “dry steam” conditions. The obtained results allow the Primorskoye epithermal deposit to be attributed to the intermediate class. The information present in the article is practically valuable for the regional forecast and metallogenic developments as well as for searching and assessing the epithermal Ag-Au deposits.

The mineralogical–geochemical and thermobarogeochemical features of the Teploe Ag–Au epithermal deposit are considered. The dissolution and redeposition of ore minerals are a result of thermal metamorphism. The redistribution of Ag leads to the formation of lenaite and exsolution structures in minerals of the Cu–Ag–S system; abundant stromeyerite, jalpaite, and mckinstryite compose a significant amount of ores. The atypical physicochemical parameters of the formation of ores include high (for epithermal mineralization) temperatures and low salinity and density of the fluid typical of a dry vapor. The results of fluid inclusion study ascribe the Teploe deposit to an intermediate class of epithermal deposits.