| 词条 | Wills Creek Formation |
| 释义 |
| name = Wills Creek Formation | image = Wills Creek Fm fold.jpg | caption = Tight anticlinal fold in the Wills Creek Formation, along Route 22, Neff, Huntingdon County, Pennsylvania | type = sedimentary | age = Silurian | period = Silurian | prilithology = Sandstone, shale | otherlithology = Siltstone, limestone, dolostone | namedfor = Wills Creek at Cumberland, Allegany County, Maryland | namedby = P. R. Uhler, 1905[1] | region = Appalachian Mountains | country = | coordinates = | unitof = | subunits = | underlies = Tonoloway Formation | overlies = Bloomsburg Formation and Williamsport Formation | thickness = | extent = Pennsylvania, Maryland, Virginia, West Virginia | area = | map = | map_caption = }} Wills Creek Formation is a mapped Silurian bedrock unit in Pennsylvania, Maryland, Virginia, and West Virginia. DescriptionThe Wills Creek is defined as a moderately well bedded greenish-gray shale containing local limestone and sandstone zones, or more specifically as an olive to yellowish-gray, thin-bedded sandstone, calcareous shale, dolostone, argillaceous limestone, and sandstone. Red shale and siltstone occur in the lower part of the formation. The formation has a thickness between 450 feet and 600 feet in Maryland and 445 to 620 feet in Pennsylvania.[2] The Wills Creek forms the bedrock of the valley around and to the east of Lewistown, Pennsylvania.[3] FossilsThe Wills Creek Limestone contain fossils from the Pridoli to the Ludlow epoch, or 422.9 to 418.1 Ma.[4] Dean et al. (1985) describe the Wills Creek as sparsely fossiliferous.[5] Conodonts have been identified in the Wills Creek in Virginia (Ozarkodina snajdri crispa Zone).[6] Notable outcrops
AgeRelative age dating of the Wills Creek places it in the Silurian period. It rests conformably a top the Bloomsburg Formation and below the Tonoloway Formation.[7] Economic useThe Wills Creek is a poor source of construction material and is only suitable as common fill.[8] See also
References1. ^Uhler, P.R., 1905, The Niagara period and its associates near Cumberland, Maryland: Maryland Academy of Science Transactions, v. 2, p. 19-26. {{Stratigraphic column of West Virginia}}2. ^{{cite web | url = http://www.geosc.psu.edu/news/features/gold/Final%20report%20%20Gold%20&%20Doden/Final%20Tables/Table%201%20Strat%20section.pdf| title = Table 1. Paleozoic Stratigraphic Section in Central Pennsylvania | work = Geological Report On The Skytop Road Cuts| publisher = Pennsylvania State University Department of Geosciences | year = 2004}} 3. ^{{cite map|url=http://www.dcnr.state.pa.us/topogeo/openfile/lewistown.pdf|format=pfd|title=Bedrock Geologic Map of the Lewistown Quadrangle, Mifflin and Juniata Counties, Pennsylvania| author = McElroy, Thomas A.| year = 2004 | publisher = Pennsylvania Geological Survey}} 4. ^{{cite web |url=http://paleodb.org/cgi-bin/bridge.pl?action=displayStrata&group_hint=&group_formation_member=Wills%20Creek%20Limestone |title= Wills Creek Limestone Formation| publisher= Advisory Board of the Paleobiology Database | work= The Paleobiology Database| accessdate=2008-01-26 |format= }} 5. ^Dean, S.L., Kulander, B.R., and Lessing, Peter, 1985, Geology of the Capon Springs, Mountain Falls, Wardensville, Woodstock, and Yellow Springs quadrangles, Hampshire and Hardy Counties, West Virginia: West Virginia Geological and Economic Survey Map, 26, 1 sheet, scale 1:24,000 6. ^Harris, A.G., Stamm, N.R., Weary, D.J., Repetski, J.E., Stamm, R.G., and Parker, R.A., 1994, Conodont color alteration index (CAI) map and conodont-based age determinations for the Winchester 30' x 60' quadrangle and adjacent area, Virginia, West Virginia, and Maryland: U.S. Geological Survey Miscellaneous Field Studies Map, MF-2239, 40 p., 1 sheet, scale 1:100,000 7. ^{{cite web |url=http://www.mgs.md.gov/esic/geo/lgdalleg.html |title=Allegheny Plateau and Valley and Ridge | work = Geologic Map of Maryland | year = 1968 | publisher=Maryland Geological Survey|accessdate=2008-01-26 }} 8. ^{{cite journal|url=http://www.dcnr.state.pa.us/topogeo/openfile/mcalevysfort.pdf|format=pdf|author1=Doden, Arnold G. |author2=Gold, David P. |lastauthoramp=yes |year=2008|title=Bedrock Geologic Map of The Mc Alevys Fort Quadrangle, Huntingdon, Centre, and Mifflin Counties, Pennsylvania|publisher=Pennsylvania Geological Survey}} 14 : Geologic formations of Maryland|Geologic formations of Pennsylvania|Geologic formations of Virginia|Geologic formations of West Virginia|Silurian System of North America|Mudstone formations|Limestone formations of the United States|Sandstone formations of the United States|Shale formations of the United States|Silurian Maryland|Silurian geology of Pennsylvania|Silurian geology of Virginia|Silurian West Virginia|Silurian southern paleotemperate deposits |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。