ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS)
The Kara ore node is located within the Sretensk-Kara ore region of East Transbaikalia. The geological structure of this area is complex due to its location within the Mongol-Okhotsk suture, the zone wherein the Siberian and Mongolia-China continents collided into each other at the turn of the Early...
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Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust
2016-12-01
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| Series: | Геодинамика и тектонофизика |
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| Online Access: | https://www.gt-crust.ru/jour/article/view/315 |
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| author | M. G. Volkova A. M. Spiridonov A. A. Borovikov N. V. Bryansky Е. A. Savina |
| author_facet | M. G. Volkova A. M. Spiridonov A. A. Borovikov N. V. Bryansky Е. A. Savina |
| author_sort | M. G. Volkova |
| collection | DOAJ |
| description | The Kara ore node is located within the Sretensk-Kara ore region of East Transbaikalia. The geological structure of this area is complex due to its location within the Mongol-Okhotsk suture, the zone wherein the Siberian and Mongolia-China continents collided into each other at the turn of the Early and Middle Jurassic. During the plate collision, intense magmatism was accompanied by the formation of focal-dome, dome-ring and other structures. The Kara ore node is controlled by the Ust-Kara focal dome-ring structure. The central part of latter is composed of Kara-Chacha granitoids from the Amudzhikan-Sretensk intrusive complex (J3-K1) with the system of subvolcanic and vein formations, including grorudites. It is suggested that gold mineralization in the study area is genetically related to grorudites; however, physical and chemical conditions for the formation of these alkaline rocks, their genesis and role in the hydrothermal gold-ore process still have not been sufficiently investigated. To this end, the authors of this paper have studied fluid inclusions (FI) in quartz from these rocks. It has been found that quartz porphyry phenocrysts in grorudite contain FI of diverse forms, the size of which ranges from 5 to 48 microns. Measured temperatures of ice melting (–2.5°C) and complete homogenization into liquid (350 °C) show that the concentration of salts in the fluid amounts to 4.2 wt % of eq. NaC, its density is 0.64 g/cm3, and the pressure is 1.6 kb. At LA-ICP-MS of individual FI, clear analytical signals were derived from Na and K. As, Mo, Sb, Cs, W, and Hg were traced in significant quantities. The Raman scanning showed the presence of N2 in the primary (substantially gaseous) FI, and CO2, N2, and CH4 in the primary-secondary FI. |
| format | Article |
| id | doaj-art-c667e8f4c4534000ab01fa9fe71aea3a |
| institution | DOAJ |
| issn | 2078-502X |
| language | English |
| publishDate | 2016-12-01 |
| publisher | Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust |
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| series | Геодинамика и тектонофизика |
| spelling | doaj-art-c667e8f4c4534000ab01fa9fe71aea3a2025-08-20T03:01:59ZengRussian Academy of Sciences, Siberian Branch, Institute of the Earth's crustГеодинамика и тектонофизика2078-502X2016-12-017467969010.5800/GT-2016-7-4-0228223ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS)M. G. Volkova0A. M. Spiridonov1A. A. Borovikov2N. V. Bryansky3Е. A. Savina4A.P. Vinogradov Institute of Geochemistry, Siberian Branch of RASA.P. Vinogradov Institute of Geochemistry, Siberian Branch of RASV.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of RASA.P. Vinogradov Institute of Geochemistry, Siberian Branch of RASA.P. Vinogradov Institute of Geochemistry, Siberian Branch of RASThe Kara ore node is located within the Sretensk-Kara ore region of East Transbaikalia. The geological structure of this area is complex due to its location within the Mongol-Okhotsk suture, the zone wherein the Siberian and Mongolia-China continents collided into each other at the turn of the Early and Middle Jurassic. During the plate collision, intense magmatism was accompanied by the formation of focal-dome, dome-ring and other structures. The Kara ore node is controlled by the Ust-Kara focal dome-ring structure. The central part of latter is composed of Kara-Chacha granitoids from the Amudzhikan-Sretensk intrusive complex (J3-K1) with the system of subvolcanic and vein formations, including grorudites. It is suggested that gold mineralization in the study area is genetically related to grorudites; however, physical and chemical conditions for the formation of these alkaline rocks, their genesis and role in the hydrothermal gold-ore process still have not been sufficiently investigated. To this end, the authors of this paper have studied fluid inclusions (FI) in quartz from these rocks. It has been found that quartz porphyry phenocrysts in grorudite contain FI of diverse forms, the size of which ranges from 5 to 48 microns. Measured temperatures of ice melting (–2.5°C) and complete homogenization into liquid (350 °C) show that the concentration of salts in the fluid amounts to 4.2 wt % of eq. NaC, its density is 0.64 g/cm3, and the pressure is 1.6 kb. At LA-ICP-MS of individual FI, clear analytical signals were derived from Na and K. As, Mo, Sb, Cs, W, and Hg were traced in significant quantities. The Raman scanning showed the presence of N2 in the primary (substantially gaseous) FI, and CO2, N2, and CH4 in the primary-secondary FI.https://www.gt-crust.ru/jour/article/view/315kara ore nodegroruditesgold mineralizationfluid inclusionsraman scanning |
| spellingShingle | M. G. Volkova A. M. Spiridonov A. A. Borovikov N. V. Bryansky Е. A. Savina ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS) Геодинамика и тектонофизика kara ore node grorudites gold mineralization fluid inclusions raman scanning |
| title | ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS) |
| title_full | ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS) |
| title_fullStr | ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS) |
| title_full_unstemmed | ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS) |
| title_short | ALKALINE VEIN ROCKS OF THE KARA ORE NODE: THE COMPOSITION OF ORE-FORMING SOLUTIONS AND CONDITIONS OF THEIR FORMATION (BASED ON THE STUDY OF FLUID INCLUSIONS) |
| title_sort | alkaline vein rocks of the kara ore node the composition of ore forming solutions and conditions of their formation based on the study of fluid inclusions |
| topic | kara ore node grorudites gold mineralization fluid inclusions raman scanning |
| url | https://www.gt-crust.ru/jour/article/view/315 |
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