Fossiliferous sandstone (Logan Formation, Lower Mississippian; eastern Ohio, USA) 3 : 無料・フリー素材/写真
Fossiliferous sandstone (Logan Formation, Lower Mississippian; eastern Ohio, USA) 3 / 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 | Fossiliferous sandstone from the Mississippian of Ohio, USA.This is a bedding plane view of a quartzose sandstone piece derived from the Logan Formation (Lower Mississippian) of eastern Ohio. The rounded structures are crinoid fossils, which are common in parts of the Logan Formation. Crinoids (sea lilies) are sessile, benthic, filter-feeding, marine invertebrates related to starfish. A crinoid is essentially a starfish on a stick. The stick, or stem, or stalk, consists of stacked poker chip-like structures called columnals. The hard parts of the crinoid skeleton are composed of calcite. The crinoid columnals seen here are preserved as molds - the calcite has been dissolved away. The yellowish-brown coloration of each fossil is from limonite (FeO·OH·nH2O - hydrous iron hydroxy-oxide).Classification: Animalia, Echinodermata, CrinoideaStratigraphy: Logan Formation (probably from the Byer Sandstone Member in the lower Logan Formation), Waverly Group, lower Osagean Stage, upper Lower MississippianProvenance: unknown, but possibly from Licking County, Ohio, USALocality: landscaping stone at "Ye Olde Mill", an ice cream factory south of Utica, east-central Ohio, USA---------------Info. at:en.wikipedia.org/wiki/Crinoid |
| 撮影日 | 2025-05-11 16:08:23 |
| 撮影者 | James St. John |
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