Champlain Black Marble (Crown Point Limestone, Middle Ordovician; Vermont, USA) 4 : 無料・フリー素材/写真
Champlain Black Marble (Crown Point Limestone, Middle Ordovician; Vermont, USA) 4 / 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 | "Champlain Black Marble" - fossiliferous limestone from the Ordovician of Vermont, USA. (public display, Vermont Marble Exhibit, Proctor, Vermont, USA)In the commercial decorative stone trade, “marble” is used to refer to a wide variety of relatively soft rocks (H = 3 to 5) that will take a fine polish. These include true marbles and rocks that aren’t marbles, such as limestones, tectonic breccias, and serpentinites. True marbles are calcitic, crystalline-textured metamorphic rocks.The black material shown above is called "Champlain Black Marble" (also known as "Champlain Fossil Marble"), but is really Ordovician-aged limestone of the Crown Point Limestone. Decent-sized fossils are commonly encountered in this rock, such as gastropods, cephalopods, and bryozoan colonies.The fossil seen here is a moderately large, low-spired gastropod called Maclurites magna. The gastropods (snails & slugs) are a group of molluscs that occupy marine, freshwater, and terrestrial environments. Most have a calcareous external shell (the snails). Some lack a shell completely, or have reduced internal shells (the slugs & sea slugs & pteropods). Most members of the Gastropoda are marine. Most marine snails are herbivores (algae grazers) or predators/carnivores.Maclurites magna is sometimes jokingly called "Big Mac".Classification: Animalia, Mollusca, Gastropoda, Archaeogastropoda, Euomphalina, Macluritoidea, MacluritidaeStratigraphy: Crown Point Limestone, lower Middle OrdovicianProvenance: possibly the Fisk Quarry or the Goodsell Quarry, Vermont, USA |
| 撮影日 | 2006-09-07 11:13:02 |
| 撮影者 | James St. John |
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