Shear-related gold mineralization in Northwest Ghana: The Julie deposit |
| |
| Institution: | 1. Université de Toulouse, CNRS, Géosciences Environnement Toulouse, Institut de Recherche pour le Développement, Observatoire Midi-Pyrénées, 14 Av. Edouard Belin, F-31400 Toulouse, France;2. Azumah Resources Ghana limited, PMB CT452, Cantonments, Accra, Ghana;3. IFAN Cheikh Anta Diop, Dakar, Senegal;4. Centre for Exploration Targeting, School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia;1. Geological Survey of Western Australia, Mineral House, 100 Plain St, EAST PERTH 6004, Australia;2. Centre for Microscopy Characterisation and Analysis, The University of Western Australia, 35 Stirling Hwy, CRAWLEY, WA 6009, Australia;1. School of Geography, Geology and the Environment, Kingston University London, Kingston upon Thames KT1 2EE, UK;2. Randgold Resources Ltd, Unity Chambers, Halkett Street, St Helier JE2 4WJ, Jersey;3. Scottish Universities Environmental Research Centre, East Kilbride, Glasgow, G75 0QF, Scotland;1. Université des Sciences, des Techniques et des Technologies de Bamako, Département de Géologie, BP E 3206 Bamako, Mali;2. Université de Toulouse, CNRS, Géosciences Environnement Toulouse, Institut de Recherche pour le Développement, Observatoire Midi-Pyrénées, 14 Av. Edouard Belin, F-31400 Toulouse, France;3. ONG-D Le Soleil dans la Main asbl, 48 Duerfstrooss, L-9696 Winseler, Luxembourg;1. Department of Petrology and Economic Geology, Geological Survey of Denmark and Greenland, Øster Voldgade 10, 1350 Copenhagen K, Denmark;2. Mauritanian Copper Mines S.A., Ilot D49 Tevrag Zeina, BP 5045, Nouakchott, Mauritania;1. Université de Toulouse, CNRS, Géosciences Environnement Toulouse, Institut de Recherche pour le Développement, Observatoire Midi-Pyrénées, 14 Av. Edouard Belin, F-31400 Toulouse, France;2. Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Département de Géologie, BP 1796 Fès, Morocco;3. Iamgold Exploration, 3503 Av. Al Qods Hippodrome, BP 2699 Bamako, Mali;4. Avnel Gold Mining Limited, 39 Cheval Place, London SW7 1EW, UK |
| |
| Abstract: | The Julie deposit is currently the largest gold prospect in NW Ghana. It is hosted in sheared granitoids of TTG composition of the Paleoproterozoic Julie greenstone belt. The main mineralization consists of a corridor of gold-bearing quartz veins forming a network of a few tens of metres in thickness, trending E–W and dipping 30–60° N, contained within the main shear zone that affects these rocks. The core of this vein corridor is altered by sericite, quartz, ankerite, calcite, tourmaline and pyrite, and is surrounded by an outer halo consisting of albite, sericite, calcite, chlorite, pyrite and rutile. A second set of veins, conjugate to the first set, occurs in the area. These veins have alteration halos with a similar mineralogy as the main corridor, however, their extent, as well as the size of the mineralization, is less important. In the main corridor, gold forms micron-sized grains that occur in pyrite as inclusions, on its edges, and in fractures crosscutting it. Silver, tellurium, bismuth, copper and lead commonly accompany the gold. Pyrite occurs disseminated in the veins and in the surrounding rocks. Up to several ppm Au occurs in the structure of pyrite from the main mineralization. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
