Academic Journal
Magmatic Cu-Ni-PGE-Au sulfide mineralisation in alkaline igneous systems: An example from the Sron Garbh intrusion, Tyndrum, Scotland
| العنوان: | Magmatic Cu-Ni-PGE-Au sulfide mineralisation in alkaline igneous systems: An example from the Sron Garbh intrusion, Tyndrum, Scotland |
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| المؤلفون: | Graham, S.D., Holwell, D.A., McDonald, I., Jenkin, G.R.T., Hill, N.J., Boyce, A.J., Smith, J., Sangster, C. |
| بيانات النشر: | Elsevier |
| سنة النشر: | 2017 |
| المجموعة: | University of Glasgow: Enlighten - Publications |
| الوصف: | Magmatic sulfide deposits typically occur in ultramafic-mafic systems, however, mineralisation can occur in more intermediate and alkaline magmas. Sron Garbh is an appinite-diorite intrusion emplaced into Dalradian metasediments in the Tyndrum area of Scotland that hosts magmatic Cu-Ni-PGE-Au sulfide mineralisation in the appinitic portion. It is thus an example of magmatic sulfide mineralisation hosted by alkaline rocks, and is the most significantly mineralised appinitic intrusion known in the British Isles. The intrusion is irregularly shaped, with an appinite rim, comprising amphibole cumulates classed as vogesites. The central portion of the intrusion is comprised of unmineralised, but pyrite-bearing, diorites. Both appinites and diorites have similar trace element geochemistry that suggests the diorite is a more fractionated differentiate of the appinite from a common source that can be classed with the high Ba-Sr intrusions of the Scottish Caledonides. Mineralisation is present as a disseminated, primary chalcopyrite-pyrite-PGM assemblage and a blebby, pyrite-chalcopyrite assemblage with significant Co-As-rich pyrite. Both assemblages contain minor millerite and Ni-Co-As-sulfides. The mineralisation is Cu-, PPGE-, and Au-rich and IPGE-poor and the platinum group mineral assemblage is overwhelmingly dominated by Pd minerals; however, the bulk rock Pt/Pd ratio is around 0.8. Laser ablation analysis of the sulfides reveals that pyrite and the Ni-Co-sulfides are the primary host for Pt, which is present in solid solution in concentrations of up to 22 ppm in pyrite. Good correlations between all base and precious metals indicate very little hydrothermal remobilisation of metals despite some evidence of secondary pyrite and PGM. Sulfur isotope data indicate some crustal S in the magmatic sulfide assemblages. The source of this is unlikely to have been the local quartzites, but S-rich Dalradian sediments present at depth. The generation of magmatic Cu-Ni-PGE-Au mineralisation at Sron Garbh can be attributed to ... |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | text |
| اللغة: | English |
| Relation: | http://eprints.gla.ac.uk/134777/1/134777.pdf; Graham, S.D., Holwell, D.A., McDonald, I., Jenkin, G.R.T., Hill, N.J., Boyce, A.J. , Smith, J. and Sangster, C. (2017) Magmatic Cu-Ni-PGE-Au sulfide mineralisation in alkaline igneous systems: An example from the Sron Garbh intrusion, Tyndrum, Scotland. Ore Geology Reviews , 80, pp. 961-984. (doi:10.1016/j.oregeorev.2016.08.031 ) |
| الاتاحة: | http://eprints.gla.ac.uk/134777/ http://eprints.gla.ac.uk/134777/1/134777.pdf |
| Rights: | cc_by_4 |
| رقم الانضمام: | edsbas.18C8B019 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |