Underclay below the Bedford Coal (Middle Pennsylvanian; Noland Tunnel's north portal outcrop, Tunnel Hill, Coshocton County, Ohio, USA) 1 : 無料・フリー素材/写真
Underclay below the Bedford Coal (Middle Pennsylvanian; Noland Tunnel's north portal outcrop, Tunnel Hill, Coshocton County, Ohio, USA) 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 | Underclay in the Pennsylvanian of Ohio, USA.This eastern Ohio exposure is in the Pottsville Group, a Pennsylvanian-aged cyclothemic succession containing nonmarine shales, marine shales, siltstones, sandstones, coals, marine limestones, and chert ("flint"). The lower Pottsville dates to the late Early Pennsylvanian. The upper part dates to the early Middle Pennsylvanian. The Lower-Middle Pennsylvanian boundary is apparently somewhere near the Boggs Member (?).The ledge at the top of this photo is the Bedford Coal, which is here composed of bituminous coal and cannel coal. Below the coal is a gray-colored, soft "underclay", composed of shale that has been subjected to chemical weathering from minor sulfuric acid percolating downward from the coal. The sulfuric acid was generated by oxidation of pyrite (in the presence of water) in the coal. Pyrite in the Bedford Coal occurs as small nodules, disseminated tiny crystals, and is in partially pyritized fossil charcoal.Stratigraphy: Upper Mercer Limestone over Bedford Coal, upper Pottsville Group, Atokan Stage, lower Middle PennsylvanianLocality: Tunnel Hill North Portal Outcrop (= Noland Tunnel's northern portal), ~1.75 air miles north-northeast of the town of Tunnel Hill, western Coshocton County, eastern Ohio, USA (~40° 16’ 33.27” North latitude, ~82° 01’ 53.04” West longitude) |
| 撮影日 | 2014-11-26 10:14:51 |
| 撮影者 | James St. John |
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