Dried mudpot spatter above Artists Paintpots' northeastern pit (10 August 2011) : 無料・フリー素材/写真
Dried mudpot spatter above Artists Paintpots' northeastern pit (10 August 2011) / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | Mudpots, or paintpots, are rare hydrothermal features. At such sites, volcanic gases rise through “mud” - a thick slurry of hot, acidic water mixed with fine-grained clay minerals. The clay minerals formed by chemical decomposition of rhyolite lava flows by naturally-occurring sulfuric acid (H2SO4). The sulfuric acid is the result of oxidation of volcanic hydrogen sulfide gas (H2S). From boreal spring to boreal summer, the viscosity of the mudpots increases. Gases reaching the top surface energetically push hot blobs of mud into the air, sometimes up to 20 feet high.Artists Paintpots are one of the two best, easily accessible mudpot areas in Yellowstone Park, Wyoming. They are are located at Paintpot Hill in the Gibbon Geyser Basin. The rocks that were decomposed to form the mudpots are Paintpot Hill Dome rhyolites (205,000 to 225,000 years old, upper Middle Pleistocene). Rhyolite is a felsic, aphanitic, extrusive igneous rock - it is a common lithology at Yellowstone, where entire plateaus are composed of Pleistocene-aged rhyolite lavas. |
| 撮影日 | 2011-08-09 17:41:55 |
| 撮影者 | James St. John |
| タグ | |
| 撮影地 |