Bear Valley Strip Mine: Difference between revisions
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[[Image:Bear Valley Strip Mine 1.jpg|thumb|300px|View of the Bear Valley Strip Mine from the north wall facing southeast, with the "Whaleback" in center]] |
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{{commons category|Bear Valley Strip Mine}} |
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The '''Bear Valley Strip Mine''' is an abandoned [[Surface mining|strip mine]] located to the southwest of the town of [[Shamokin, Pennsylvania|Shamokin]], Pennsylvania. It lies in the Western Middle Field of the [[Anthracite]] belt in the [[Ridge-and-Valley Appalachians]], where the [[Pennsylvanian]] [[Llewellyn Formation]] is exposed. The property is owned by the [[Reading Anthracite Company]]. |
The '''Bear Valley Strip Mine''' is an abandoned coal [[Surface mining|strip mine]] located in [[Coal Township, Northumberland County, Pennsylvania|Coal Township, Northumberland County]], to the southwest of the town of [[Shamokin, Pennsylvania|Shamokin]], Pennsylvania. It lies in the [[Western Middle Anthracite Field|Western Middle Field]] of the [[Anthracite]] belt in the [[Ridge-and-Valley Appalachians]], where the [[Pennsylvanian (geology)|Pennsylvanian]] [[Llewellyn Formation]] is exposed. The property is owned by the [[Reading Anthracite Company]]. |
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<ref name=Nickelsen1>Sequence of structural stages of the Alleghany orogeny at the Bear Valley Strip Mine, Shamokin, Pennsylvania. Nickelsen, R. P. (Dept. of Geology, [[Bucknell University]]) [[Geological Society of America]] Centennial Field Guide—Northeastern Section, 1987</ref> |
<ref name=Nickelsen1>Sequence of structural stages of the Alleghany orogeny at the Bear Valley Strip Mine, Shamokin, Pennsylvania. Nickelsen, R. P. (Dept. of Geology, [[Bucknell University]]) [[Geological Society of America]] Centennial Field Guide—Northeastern Section, 1987</ref> |
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The central [[anticline]] in the valley is often called the "Whaleback". |
The central [[anticline]] in the valley is often called the "Whaleback". |
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The sequence of structural deformation is outlined as follows<ref name=Nickelsen1/> |
The sequence of structural deformation is outlined as follows:<ref name=Nickelsen1/> |
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File:Concretions Bear Valley.jpg|[[Concretion]]s in the south wall |
File:Concretions Bear Valley.jpg|[[Concretion]]s in the south wall |
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File:Bear Valley east wall.jpg|View of the east wall from the Whaleback |
File:Bear Valley east wall.jpg|View of the east wall from the Whaleback |
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File:Bear Valley Slickensides.jpg|[[Slickensides]] on a fault plane, south wall. Lens cap 5. |
File:Bear Valley Slickensides.jpg|[[Slickensides]] on a fault plane, south wall. Lens cap 5.8 cm wide. |
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File:Stigmaria Bear Valley upright.jpg|Upright ''[[ |
File:Stigmaria Bear Valley upright.jpg|Upright ''[[Sigillaria]]'' in dipping sandstone and shale beds of the north wall. A so-called "[[Polystrate fossil]]". |
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File:DCP 0776. |
File:Bear Valley Whaleback DCP 0776.jpg|Another image of the south wall and Whaleback |
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File:Stigmaria Bear Valley Strip Mine.jpg|[[Stigmaria]] root fossils |
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</gallery> |
</gallery> |
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{{coord|40|45.8|N|76|35.7|W|region:US-PA_source:GoogleEarth|display=title}} |
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[[Category:Coal mines in the United States]] |
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[[Category:Geography of Northumberland County, Pennsylvania]] |
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{{NorthumberlandCountyPA-geo-stub}} |
Latest revision as of 19:12, 4 August 2023
The Bear Valley Strip Mine is an abandoned coal strip mine located in Coal Township, Northumberland County, to the southwest of the town of Shamokin, Pennsylvania. It lies in the Western Middle Field of the Anthracite belt in the Ridge-and-Valley Appalachians, where the Pennsylvanian Llewellyn Formation is exposed. The property is owned by the Reading Anthracite Company. [1]
The coal and other overlying rock has been removed by mining down to a resistant sandstone bed, revealing the three-dimensional structures of folding and faulting caused by the Alleghany Orogeny. Students of geology have visited the location for decades due to the quality of exposures.
The central anticline in the valley is often called the "Whaleback".
The sequence of structural deformation is outlined as follows:[1]
Stage | Deformation event |
---|---|
I | Joint formation in coal |
II | Joint formation with quartz fiber fillings in sandstone and ironstone |
III | Pressure solution and primary crenulation cleavage |
IV | Conjugate wrench and wedge faults form |
V | Large-scale folding |
VI | Extensional jointing and faulting |
Gallery
[edit]-
Concretions in the south wall
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View of the east wall from the Whaleback
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Slickensides on a fault plane, south wall. Lens cap 5.8 cm wide.
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Upright Sigillaria in dipping sandstone and shale beds of the north wall. A so-called "Polystrate fossil".
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Another image of the south wall and Whaleback
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Stigmaria root fossils
References
[edit]- ^ a b Sequence of structural stages of the Alleghany orogeny at the Bear Valley Strip Mine, Shamokin, Pennsylvania. Nickelsen, R. P. (Dept. of Geology, Bucknell University) Geological Society of America Centennial Field Guide—Northeastern Section, 1987
40°45.8′N 76°35.7′W / 40.7633°N 76.5950°W