The Bloomsburg is defined as a grayish-red and greenish-gray claystone, argillaceoussiltstone, shale, and very fine to fine-grained sandstone,[4] arranged in fining-upward cycles.[5] Although the Bloomsburg can sometimes be green to gray, its most dominant color is red and they are often called "The Bloomsburg Red Beds". This is significant in the Appalachian Basin since it marks the first large scale terrestrial collection of sediments in the rock record. Most of the sediments that were deposited before this time were marine, or a small scale terrestrial zone.
In New Jersey, the Bloomsburg Red Beds were previously called the "High Falls Shale" or "High Falls Formation".[6]
Depositional environmentedit
The depositional environment of the Bloomsburg was mostly terrestrial or shallow marine deposits resulting in a molasse sequence produced by the Taconic orogeny. The red color is often evidence that the sediments were deposited in arid or oxidizing conditions. The upper parts of the Bloomsburg are thought to be a marine transition zone.[7]
Stratigraphyedit
Early American geologists theorized that these beds correlated with Old Red Sandstone found in Scotland.,[2] but the Old Red Sandstone is Devonian in age, or much younger than the Bloomsburg.
The Bloomsburg rests conformably above the Clinton Group[4] and Shawangunk Formation, and has a complex upper contact. In eastern Pennsylvania and New Jersey, the upper part of the Bloomsburg marks the Wallbridge Unconformity. To the west, the Wills Creek Formation lies conformably atop the Bloomsburg. Further west, the McKenzie Member of the Mifflintown Formation interfingers with the Bloomsburg and eventually, the Bloomsburg pinches out into the Mifflintown.[8]
Fossilsedit
There are numerous fossils found in the Bloomsburg, mostly in the upper parts of the formation. There are trace fossils of early land plants and brachiopod fossils in the upper marine transitional zones.[7]
Notable Exposuresedit
Outcrop of the Bloomsburg Formation at Port Clinton
Relative age dating of the Bloomsburg places it in the Upper Silurian period, being deposited between 417 and 410 (±5) million years ago.
Economic usesedit
The Bloomsburg formation is a source of material for the manufacture of brick and other clay products, as well as a local building stone.[10]
Referencesedit
^Paleozoic Sedimentary Successions of the Virginia Valley & Ridge and Plateau
^ abWood, G.H., Trexler, J.P., Kehn, T.M., (1964). Geology of the West-Central Part of the Southern Anthracite Field and Adjoining Areas, Pennsylvania. United States Geological Survey, C-46.
^White, I.C., 1883, The geology of the Susquehanna River region in the six Counties of Wyoming, Lackawanna, Luzerne, Columbia, Montour, and Northumberland: Pennsylvania Geological Survey Report of Progress, 2nd series, v. G7, 464 p.
^ abJackson, Margaret S.; Hanley, Peter M. & Sak, Peter B. (2007). (PDF). Open File Report OFBM-07-05.0. Pennsylvania Geological Survey. Archived from the original (PDF) on June 9, 2011. Retrieved 2008-01-26.
^ abHoskins, D.M., (1961). Stratigraphy and paleontology of the Bloomsburg Formation of Pennsylvania and adjacent states: G36. Pennsylvania Geologic Survey, Harrisburg, Pennsylvania.
^Berg, T.M., et al., (1983). Stratigraphic Correlation Chart of Pennsylvania: G75, Pennsylvania Geologic Survey, Harrisburg, Pennsylvania.
^Faill, R.T., Glover, A.D., and Way, J.H., 1989, Geology and mineral resources of the Blandburg, Tipton, Altoona, and Bellwood quadrangles, Blair, Cambria, Clearfield and Centre Counties, Pennsylvania: Pennsylvania Geological Survey Topographic and Geologic Atlas, 4th series, 86, 209 p., scale 1:24,000 and 1:48,000
^Doden, Arnold G. & Gold, David P. (2008). (PDF). Pennsylvania Geological Survey. Archived from the original (PDF) on June 9, 2011. {{cite journal}}: Cite journal requires |journal= (help)
bloomsburg, formation, silurian, mapped, bedrock, unit, pennsylvania, jersey, york, maryland, named, town, bloomsburg, pennsylvania, which, first, described, bloomsburg, marked, first, occurrence, sedimentary, rocks, appalachian, basin, stratigraphic, range, g. The Silurian Bloomsburg Formation is a mapped bedrock unit in Pennsylvania New Jersey New York and Maryland It is named for the town of Bloomsburg Pennsylvania in which it was first described The Bloomsburg marked the first occurrence of red sedimentary rocks in the Appalachian Basin Bloomsburg FormationStratigraphic range Gorstian Ludfordian 1 425 Ma PreꞒ Ꞓ O S D C P T J K Pg N A hand sample of the Bloomsburg Siltstone from Port Clinton PennsylvaniaTypesedimentaryUnderliesWills Creek FormationOverliesClinton Group McKenzie Formation Mifflintown Formation and Shawangunk FormationThicknessup to 5 000 feet 1 520 m 2 LithologyPrimarySiltstoneOtherShale Claystone Sandstone LimestoneLocationRegionAppalachian Basin of eastern North AmericaExtentMaryland New Jersey New York Pennsylvania and VirginiaType sectionNamed forBloomsburg PennsylvaniaNamed byI C White 1883 3 Contents 1 Description 1 1 Depositional environment 2 Stratigraphy 2 1 Fossils 2 2 Notable Exposures 3 Age 4 Economic uses 5 References 6 See alsoDescription editThe Bloomsburg is defined as a grayish red and greenish gray claystone argillaceous siltstone shale and very fine to fine grained sandstone 4 arranged in fining upward cycles 5 Although the Bloomsburg can sometimes be green to gray its most dominant color is red and they are often called The Bloomsburg Red Beds This is significant in the Appalachian Basin since it marks the first large scale terrestrial collection of sediments in the rock record Most of the sediments that were deposited before this time were marine or a small scale terrestrial zone In New Jersey the Bloomsburg Red Beds were previously called the High Falls Shale or High Falls Formation 6 Depositional environment edit The depositional environment of the Bloomsburg was mostly terrestrial or shallow marine deposits resulting in a molasse sequence produced by the Taconic orogeny The red color is often evidence that the sediments were deposited in arid or oxidizing conditions The upper parts of the Bloomsburg are thought to be a marine transition zone 7 Stratigraphy editEarly American geologists theorized that these beds correlated with Old Red Sandstone found in Scotland 2 but the Old Red Sandstone is Devonian in age or much younger than the Bloomsburg The Bloomsburg rests conformably above the Clinton Group 4 and Shawangunk Formation and has a complex upper contact In eastern Pennsylvania and New Jersey the upper part of the Bloomsburg marks the Wallbridge Unconformity To the west the Wills Creek Formation lies conformably atop the Bloomsburg Further west the McKenzie Member of the Mifflintown Formation interfingers with the Bloomsburg and eventually the Bloomsburg pinches out into the Mifflintown 8 Fossils edit There are numerous fossils found in the Bloomsburg mostly in the upper parts of the formation There are trace fossils of early land plants and brachiopod fossils in the upper marine transitional zones 7 Notable Exposures edit nbsp Outcrop of the Bloomsburg Formation at Port ClintonRoundtop Hill Maryland along railroad grade Port Clinton Pennsylvania where bedding is nearly vertical and cleavage is visible U S Route 22 2 3 km northeast of Canoe Creek 9 Age editRelative age dating of the Bloomsburg places it in the Upper Silurian period being deposited between 417 and 410 5 million years ago Economic uses editThe Bloomsburg formation is a source of material for the manufacture of brick and other clay products as well as a local building stone 10 References edit Paleozoic Sedimentary Successions of the Virginia Valley amp Ridge and Plateau a b Wood G H Trexler J P Kehn T M 1964 Geology of the West Central Part of the Southern Anthracite Field and Adjoining Areas Pennsylvania United States Geological Survey C 46 White I C 1883 The geology of the Susquehanna River region in the six Counties of Wyoming Lackawanna Luzerne Columbia Montour and Northumberland Pennsylvania Geological Survey Report of Progress 2nd series v G7 464 p a b Jackson Margaret S Hanley Peter M amp Sak Peter B 2007 Preliminary Bedrock Geologic Map of the Middle Portion of the Susquehanna River Valley Cumberland Dauphin And Perry Counties Pennsylvania PDF Open File Report OFBM 07 05 0 Pennsylvania Geological Survey Archived from the original PDF on June 9 2011 Retrieved 2008 01 26 Berg T M Edmunds W E Geyer A R and others compilers 1980 Geologic Map of Pennsylvania Pennsylvania Geologic Survey Map 1 scale 1 250 000 Bloomsburg Red Beds a b Hoskins D M 1961 Stratigraphy and paleontology of the Bloomsburg Formation of Pennsylvania and adjacent states G36 Pennsylvania Geologic Survey Harrisburg Pennsylvania Berg T M et al 1983 Stratigraphic Correlation Chart of Pennsylvania G75 Pennsylvania Geologic Survey Harrisburg Pennsylvania Faill R T Glover A D and Way J H 1989 Geology and mineral resources of the Blandburg Tipton Altoona and Bellwood quadrangles Blair Cambria Clearfield and Centre Counties Pennsylvania Pennsylvania Geological Survey Topographic and Geologic Atlas 4th series 86 209 p scale 1 24 000 and 1 48 000 Doden Arnold G amp Gold David P 2008 Bedrock Geologic Map of The Mc Alevys Fort Quadrangle Huntingdon Centre and Mifflin Counties Pennsylvania PDF Pennsylvania Geological Survey Archived from the original PDF on June 9 2011 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help See also editGeology of Pennsylvania Retrieved from https en wikipedia org w index php title Bloomsburg Formation amp oldid 1138896522, wikipedia, wiki, book, books, library,
