Abstract
Research subject. The gold-sulphide-quartz deposits of Central Chile are typical prospecting objects, having small ore intervals (from the first tens of centimetres to 1 m), intermittent and nested ore distribution and extremely uneven gold contents.Materials and methods. The patterns of ore mineralization distribution are considered against the background of the results of modern geophysical studies of the lithosphere: the Moho surface, density and thermal regime of the upper mantle. Detailed studies were conducted on the Yapin ore field.Results. It was shown that the faults controlling gold-sulphidequartz mineralization are derivatives of shear tectonics under the conditions of a transpression regime along the Chilean active margin. At an early stage, these faults developed in a right-shift environment, which was accompanied by the introduction of diabase dikes into the northeastern faults, and gold-sulfide-quartz mineralization superimposed on the dikes was deposited during the left-shift stage. The geological structure of the deposits in the ore field Yapin was characterized. It was shown that a diverse mineralization is developed in the ore field - copper-porphyry, IOCG-type and gold-sulphide-quartz. According to geochemical data, the latter is characterized by a clear enrichment of chalcophilic elements (Au, As, Ag, Cd, Cu, Bi, Pb, Zn, Te, Co). The marked enrichment of Bi, Te and Co ores indicates the participation of magmatic fluid in ore formation and the similarity of the mineralization of the Escondida deposit with the type of gold deposits associated with granitoid intrusions. According to geochemical features, gold-sulphide-quartz mineralization in the general zoning pattern occupies a boundary position between IOCG-type objects and copper-porphyry deposits.Conclusions. The conclusion is drawn about the independence of gold-sulphide-quartz mineralization and its difference from epithermal gold deposits. It is noted that, in the volcanic belts of the North-East of Russia, the prospects for discovering unconventional gold-sulphidequartz deposits similar to those of Central Chile are rather real.
Highlights
Detailed studies were conducted on the Yapin ore field
These faults developed in a right-shift environment, which was accompanied by the introduction of diabase dikes into the northeastern faults, and gold-sulfide-quartz mineralization superimposed on the dikes was deposited during the left-shift stage
It was shown that a diverse mineralization is developed in the ore field - copper-porphyry, IOCG-type and gold-sulphide-quartz
Summary
Порфировые месторождения (Cu, Mo, Sn) активных континентальных окраин, как правило, сопровождаются непорфировыми рудными образованиями (Сидоров и др., 2006). Геологическая позиция золото-сульфидно-кварцевых месторождений Чилийской активной окраины 233 Geological position and structural features of the gold-sulfide-quartz deposits of the Chilean active margin стях зоны установлены разрозненные интервалы протяженностью 0.5–1.0 м с содержаниями золота до 5.4 г/т. Далее за ней располагаются золото-сульфидно-кварцевые проявления, концентрирующиеся в север-северо-восточных нарушениях на расстоянии 0.5–2.0 км от границы медной минерализации, вдоль западного контакта массива габбро-диоритов. А обогащенность руд Bi, Te и Со, по сравнению со средними значениями верхней коры (Тейлор, Мак-Леннан, 1988), указывает на участие в рудообразовании магматического флюида (Волков и др., 2017) и на сходство минерализации месторождения Эскондида с типом месторождений золота, связанных с интрузивами гранитоидов (Волков, Сидоров, 2018). 7. Микроэлементы в руде (Au > 0.1 г/т), околорудных метасоматитах (Au = 0.03–0.1 г/т) и вмещающих породах (Au < 0.03 г/т) золото-сульфидно-кварцевого месторождения Эскондида нормированные по отношению к средним значениям для верхней коры (Тейлор, Мак-Леннан, 1988).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
