Auriferous sulfidic hydrothermal quartz vein (gold ore) (Agnesa Vein, central zone of the Stiavnica Volcano, Central Slovakia Volcanic Field, Middle Miocene, 13-15 Ma; ~10 meters above the XIV Level, Rozalia Mine, Stvnicke Vrchy Mountains, Slovakia) 1 : 無料・フリー素材/写真
Auriferous sulfidic hydrothermal quartz vein (gold ore) (Agnesa Vein, central zone of the Stiavnica Volcano, Central Slovakia Volcanic Field, Middle Miocene, 13-15 Ma; ~10 meters above the XIV Level, Rozalia Mine, Stvnicke Vrchy Mountains, Slovakia) 1 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Auriferous sulfidic hydrothermal quartz vein (gold ore) from the Miocene of Slovakia (10.3 centimeters across at its widest).This is a beautiful sulfide-bearing hydrothermal quartz vein sample. The whitish and light to medium gray-colored material is quartz. The brassy gold-colored areas are chalcopyrite (CuFeS2 - copper iron sulfide). The silvery-gray areas (some appear blue colored from reflecting scanner light) are galena (PbS - lead sulfide). The dark gray areas are sphalerite (ZnS - zinc sulfide). This is a gold ore sample, but there is no visible, macroscopic gold. The gold occurs as microscopic inclusions up to 0.1 mm in size within the sulfide minerals. Some samples from this locality do have visible gold - usually in proximity to galena.This gold ore comes from the Rozalia Gold Mine in Slovakia, which targets an intermediate epithermal precious-metal sulfide deposit in the core of an old, eroded volcano. The ore minerals are in hydrothermal veins hosted in propylitized andesite. The original andesite has been hydrothermally altered into a calcite-chlorite-epidote-serpentine-quartz-pyrite rock resembling greenstone. The eroded volcano is a large, long-extinct, andesite stratovolcano called the Stiavnica Volcano. Several subvolcanic intrusions are present at Stiavnica, dominated by a granodiorite pluton.Geologic context & age: Agnesa Vein, central zone of the Stiavnica Volcano, Central Slovakia Volcanic Field, inner side of the Carpathian Arc, Middle Miocene, 13-15 MaLocality: approximately 10 meters above the XIV Level of the Rozalia Mine, Hodrusa-Stiavnica Ore District, Hodrusa-Hamre, Stvnicke Vrchy Mountains, southwest-central Slovakia |
| 撮影日 | 2014-12-03 19:40:59 |
| 撮影者 | James St. John |
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