FSBI Central Research Institute of Geological Prospecting for Base and Precious Metals, Moscow, Russia

A forecast-exploration model of gold deposits of the Toupugol-Khanmeishor ore cluster was developed, which made it possible to recommend geological exploration within other promising areas of the Malyi Ural volcano-plutonic belt (VPB) in the Polar Urals. The studies have demonstrated that the Manyukuyu and Kokpela potential ore clusters of the Tan’yu-Lagorta complex ore district in the southern Malyi Ural VPB represent the most promising targets for the further prospecting for lode gold mineralization assigned to various structural-compositional subtypes of the gold-sulfide-quartz mineral type.

Keywords: : Polar Urals, Malyi Ural volcano-plutonic belt, Toupugol-Khanmeishor ore cluster, Tan’yu-Lagorta ore district, gold-sulfide-quartz formation, structural-compositional types of gold mineralization (skarn-related gold, gold-sulfide-quartz, and porphyry gold types), forecast-exploration model.

Andreev Anton Vadimovich Senior researcher This email address is being protected from spambots. You need JavaScript enabled to view it.

A. P. Karpinsky Russian Geological Research Institute, St. Petersburg, Russia

Analysis of materials of the State Geological Map 1 : 1 000 000 (3rd generation) for the southern Sakha– Yakutiya territory in the course of compilation of the Minerogenic forecast map of the Russian Federation and its continental shelf, 1 : 2 500 000, and of the Map of the distribution regularities and forecast for porphyry goldcopper, large-tonnage black-shale gold, and epithermal gold deposits of the Russian Federation, 1 : 2 500 000, has allowed the authors to substantiate distinguishing the new Aldan-Vilyui ore-placer gold-bearing province with a total area of 450 000 km2 in the basins of the Lena, Aldan, and Vilyui rivers. The authors estimate the metallogenic potential of the province at 5000 t of gold. In the near future, this province may become a new extensive resource base of gold and related elements for the Russian Federation.

Keywords: Forecasting minerogenical analysis, new ore-placer gold-bearing province, Southern Yakutia.

Molchanov Anatoly Vasilievich PhD Head of Department This email address is being protected from spambots. You need JavaScript enabled to view it.

Terekhov Artem Valerievich PhD Deputy Head of Department This email address is being protected from spambots. You need JavaScript enabled to view it.

Kozlov Gleb Alexandrovich Geologist This email address is being protected from spambots. You need JavaScript enabled to view it.

Lebedev Ivan Olegovich Leading geologist This email address is being protected from spambots. You need JavaScript enabled to view it.

Khorokhorina Elena Ivanovna Leading engineer This email address is being protected from spambots. You need JavaScript enabled to view it.

Guzev Vladislav Evgenievich Engineer This email address is being protected from spambots. You need JavaScript enabled to view it.

¹FSBI Central Research Institute of Geological Prospecting for Base and Precious Metals, Moscow, Russia

² Siberian Research Institute of Geology, Geophysics and Mineral Raw Materials, Novosibirsk, Russia

The Elegest-Mezhegei, Aptara, and Shivilig forecasted gold ore clusters and the Kharalyg and Irbitei forecasted gold-silver-polymetallic ore clusters were distinguished within the East Tannu-Ola iron-copper-polymetallic-gold ore region, based on examination of historical and new geological, geochemical, and metallogenical data. Subsequently, the Urgailyg, Proezdnoe, and Chumurtuk forecasted gold ore fields were delineated within the ElegestMezhegei cluster; the Despen ore field was delineated within the Aptara ore cluster; and the Ovur-Ongesh ore field was outlined within the Shivilig cluster. In addition, the Ulug-Sailyg and Ak-Charinsk gold-molybdenum-copper ore fields were distinguished outside the ore clusters. The article summarizes the investigation history, geologicalstructural position, geological features, and geochemical specialization of the rocks of the East Tannu-Ola region. Descriptions of the ore clusters embrace peculiarities of their geological structure, ore mineralogy, and native gold, as well as parameters of the gold-sulfide-quartz, goldskarn, gold-containing polymetallic VMS, and porphyry molybdenum-copper mineralized zones. The conclusions highlight the metallogenic epochs and distribution regularities of the gold and gold-containing mineralization within the region studied.

Keywords: metallogenic regionalization, gold, East Tannu-Ola ore region, Tyva Republic.

Chernykh Alexander Ivanovich PhD General Director¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

Shirobokov Alexey Yurievich Head of Department², This email address is being protected from spambots. You need JavaScript enabled to view it.

Arsentieva Irina Viktorovna PhD Senior researcher¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

¹ FSBI Central Research Institute of Geological Prospecting for Base and Precious Metals, Moscow, Russia

² FSBI Russian Geological Research Institute, Saint Petersburg, Russia

New data are presented on the formation conditions and ages of the reduced intrusion-related Au mineralization of the Vetrenskaya area in the Central Kolyma region. The mineralization is predominantly confined to intersections of Late Jurassic minor intrusive bodies and NE-trending fracture systems and is represented by zones of thin quartz veinlets with sericite-quartz halos. The major ore mineral is gold-bearing arsenopyrite (up to 10%), while minor minerals are represented by lellingite, pyrite, chalcopyrite, and pyrrhotite. Microscopic native gold of a low fineness is paragenetically associated with bismuth minerals (bismuthine, native bismuth, and tellurides of Bi and Au), forming microinclusions (1–10 µ) in the arsenopyrite. Isochronous Re-Os age of the goldbearing arsenopyrite is 137–117 Ma, which suggests the mineralization was formed significantly later than the hosting granitoids (147–153 Ma). The reduced intrusionrelated Au ore deposit was formed at shallower depths in comparison with orogenic Au deposits, and at lower temperatures in comparison with rare metal (W, Mo) ore deposits.

Keywords: Central Kolyma region, Vetrenskaya area, gold, bismuth, tungsten, molybdenum, absolute age, ReOs, fluid inclusions, reduced intrusion-related Au ore formational type, RIRGS.

Pachersky Nikolay Viktorovich Senior researcher¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

Kryazhev Sergey Gavrilovich PhD Head of department of mineralogy and isotope geochemistry¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

Naumov Evgeniy Anatolievich PhD Deputy General Director for Research¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

Desyatova Daria Yurievna Researcher², This email address is being protected from spambots. You need JavaScript enabled to view it..

Dvurechenskaya Svetlana Stepanovna PhD Leading researcher¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

Samoilenko Maxim Victorovich Leading engineer ¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

¹ OOO Fevralskoe, St. Petersburg, Russia

² OOO Sredneuralskoe Poiskovoe Byuro, Ekaterinburg, Russia

Along with some gold-quartz deposits hosted by dunite-harzburgite massifs elsewhere in the Urals, elevated Ni concentrations were revealed within the ore field of the Anna gold-(sulfide)-quartz deposit localized in weathered oxidized dunites and harzburgites of the Pervomaisky complex (συO2p) in the Pervomaisko-Verkhoturie district of the Central Urals. The spatial association of Au and Ni concentrations in dunites-harzburgites may be attributed to a partial inheritance of Ni-controlling tectonic dislocations by those hosting gold mineralization. Therefore, the combination of halos of Ni and Au concentrations in dunite-harzburgite massifs is a favorable indicator of areas prospective for discovery of goldquartz mineralization.

Keywords: nickel anomalies, dunite-harzburgite complex, gold mineralization, prospecting and exploration, nickel silicate ore.

Motov Andrey Pavlovich PhD Director of Development¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

Malakh Yuriy Efimovich Chairman of the Board of Directors¹, This email address is being protected from spambots. You need JavaScript enabled to view it.

Voropaev Iliya Stanislavovich Chief Geologist², This email address is being protected from spambots. You need JavaScript enabled to view it.

¹ Universidade de Lisboa – Faculdade de Ciências, Portugal

² Dept. Earth Sciences, NHM London, UK

³ Wardell Armstrong International (WAI), UK

⁴ British Fluorspar Limited (BFL), UK

British Fluorspar Ltd (BFL) operates a lead-fluorite-barite deposit located in the Peak Lake District (Derbyshire, UK) with fluorspar as the main product and lead and barite as by-products. Recent analysis of the CaF2 concentrate showed high values of deleterious elements such as Pb, P, S and As, which affect the quality of the product. Grindability studies showed an overgrinding of material prior to the flotation stage with high liberation of P2O5 mainly to the fluorspar concentrate. Data obtained from bath flotation test indicated an improvement of lead recovery from 2.33% to 15.03%, decreasing Na2S to 100g/t and pH to 9 in the lead oxide circuit and a depression of P2O5 in the fluorspar flotation stage from 87% to 91% recovered in the tailings using 200 g/t of CaCl-CuSO4 as “depressant” of phosphates related minerals.

Keywords: : fluorspar flotation; lead-fluorite; barite; phosphorus.

^* Our close friend and colleague Dr. Chris Broadbent coordinated this manuscript to its final stage but sadly passed away prior to its publication. We dedicate this work to him.