Fluorite-calcite rock (probably early Neoproterozoic, 929 Ma; near Wilberforce, Ontario, Canada) 13 : 無料・フリー素材/写真
Fluorite-calcite rock (probably early Neoproterozoic, 929 Ma; near Wilberforce, Ontario, Canada) 13 / 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 | Fluorite-calcite rock from the Precambrian of Ontario, CanadaThis rock is from an igneous dike - a "vein-dike" or "vein-dyke" - that intrudes Precambrian basement rocks near Wilberforce, Ontario, Canada. The purple mineral is fluorite. The whitish-gray material is calcite.The sample probably comes from the Richardson-Fission Mine area near Radium Lake, Ontario. Purple fluorite stringers in rocks from this locality resemble gneissic foliation. The mine targeted radium that had decayed from uranium. Near uranium-bearing masses, the fluorite has a nearly black color. When broken, such fluorite emits an unpleasant odor ("fetid fluorite", or "antozonite", or "stinkspar"). A similar phenomenon was noticed long ago in some German mines. In the early 2010s, the scent was identified and verified as elemental fluorine gas (F2). This was surprising, as elemental fluorine is highly reactive.The Richardson-Fission Mine "vein-dyke" has not been dated, but similar igneous bodies occur elsewhere in Ontario. Radiometric dating from a calcite-bearing "vein-dyke" at Bear Lake Diggings revealed an early Neoproterozoic age of 929 Ma. These Ontario calcitic dikes appear to be part of an alkaline intrusive event in the Grenville Province, possibly associated with some extensional tectonics at the end of Grenville Orogeny.Locality: unrecorded / undisclosed locality near the town of Wilberforce, Ontario, Canada (but probably from the Richardson-Fission Mine area (Richardson Mine; Fission Mine), just southeast of Radium Lake & west of Cope Lake & south of Cardiff Lake, ~3.5 to 4 air-kilometers northeast of the town of Wilberforce, ~25 km west of Bancroft, Cardiff Township, Haliburton County, southeastern Ontario, southeastern Canada) |
| 撮影日 | 2024-03-06 16:50:28 |
| 撮影者 | James St. John |
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