Penokean Orogeny From Rifting to Iron Formations, and The Penokean Collisions author Davis, Peter ... known as the Algoman orogeny in the U. S. named for Algoma, Wisconsin Algoma , Kewaunee County ... orogeny in Canada. ref name ojakangas rp 32 ref name nature cite web title Voyageurs ... of the Algoman orogeny. The orogeny affected adjacent regions of northern Minnesota and Ontario ... than in subsequent orogenies. ref name stearn rp 158 It is the earliest datable orogeny in North ... grade metamorphic rocks are associated with the orogeny. ref name keck cite report title U PB ... into a system of mountains by the Algoman orogeny. ref name schwartz The volcanic beds are convert ... shear zones caused by continued compression that occurred during the Algoman orogeny. ref name resgeol ... is around mya 2500 million years ago , the time of the Kenoran orogeny. Rocks comprising the Slave province ... of Earth Category Orogeny Category Terranes ... more details
East African Orogeny is the Neoproterozoic orogeny that affects the East African Orogen. ref Stern, R. J. 1994 Neoproterozoic 900 550 Ma Arc Assembly and continental collision in the East African Orogen. Annual Review of Earth and Planetary Sciences, 22, 319 351 ref The orogeny evolved from an accretion geology accretionary orogeny involving the amalgamation of arcs and evolved into a collisional orogeny when the Neoproterozoic continent Azania ref Collins, A.S. and Windley B.F. 2002 . The Tectonic Evolution of Central and Northern Madagascar and its place in the Final Assembly of Gondwana. The Journal of Geology, 110 325 340. ref collided with the Congo Tanzania Bangweulu Block at 640 Ma. ref Collins, A.S. and Pisarevsky S.A. 2005 . Amalgamating eastern Gondwana The evolution of the Circum Indian Orogens. Earth Science Reviews. 71 229 270. ref The orogeny is the earlier of two orogenies that affects the East African Orogen ref Meert, J.G. 2003 . A synopsis of events related to the assembly of eastern Gondwana, Tectonophysics, Volume 362, pp. 1 40. ref and is followed by the Ediacaran Cambrian Kuunga Orogeny . ref Meert 2003 . ref References Reflist Tectonics stub Category Orogeny Category Proterozoic ... more details
The Alice Springs Orogeny was a major intraplate tectonic mountain building episode in central Australia responsible for the formation of a series of large mountain range s. ref Wells AT, Forman DJ, Ranford ..., Australia, Bulletin 100. ref Duration The Alice Springs Orogeny was a long lived event, beginning ... orogeny was centered in an area that had previously been a marine sedimentary basin, and involved ... Springs Orogeny had its beginnings in the Late Ordovician , continuing during the Silurian and Devonian ... much of central Australia. Prior to the Alice Springs Orogeny the Amadeus Basin Amadeus , Georgina ... Orogeny disentombed the Arunta Inlier during mainly south directed thrusting. ref Fl ttmann, T., Hand ... the late Neoproterozoic to early Cambrian Petermann Orogeny and the Devonian to Carboniferous Alice Springs Orogeny. The pattern of fault reactivation during these events is similar to the pattern of subsidence in the overlying basin. During the Alice Springs Orogeny, reactivation occurred along ... Petermann Orogeny. The major Petermann aged structures that were not buried during renewed subsidence were inactive during the Alice Springs Orogeny. The record of reactivation tells us that the presence ... continuous throughout the Alice Springs Orogeny, but focused at a number of discrete loci, situated ... Orogeny is localised by suitably oriented structural weaknesses such as faults. This theory is supported ..., intraplate orogeny and the geochemical structure of the crust A central Australian perspective ... Springs Orogeny was widespread, there are two major regions affected by significant basement involved ... structural feature reactivated during the Alice Springs Orogeny. This shear zone is associated .... In this basin the Alice Springs Orogeny caused reactivation of the Munyarai Thrust which had also undergone reactivation during the Petermann Orogeny. Shortening here resulted in southward thrusting ... Hand References reflist Category Orogeny Category Northern Territory Category Geology of the Northern ... more details
The Pan African orogeny was a series of major Neoproterozoic orogeny orogenic events mountain building which related to the formation of the supercontinent s Gondwana and Pannotia about 600 million years ago. sfn Glossary The Mozambique Belt , extending from east Antarctica through East Africa up to the Arabian Nubian Shield , formed as a suture between plates during the Pan African orogeny. sfn Cutten 2002 The Mozambique ocean began closing between Madagascar India and the Congo craton Congo Tanzania craton Tanzania craton between 700 and 580 million years ago, with closure between 600 and 500 million years ago. sfn Grantham Maboko Eglington 2003 p 417 418 References reflist colwidth 30em Sources refbegin cite web ref harv url http gsa.confex.com gsa 2002AM finalprogram abstract 43792.htm title THE MOZAMBIQUE BELT, EASTERN AFRICA TECTONIC EVOLUTION OF THE MOZAMBIQUE OCEAN AND GONDWANA AMALGAMATION last Cutten first Huntly N.C. date October 29, 2002 publisher The Geological Society of America accessdate 2011 12 28 cite web ref harvid Glossary url http www.dinodata.net Golonka GLOSSARY.pdf title Glossary of Plate Tectonic and Paleogeographic Terms format PDF accessdate 2006 04 09 not available without registration free cite book ref harv url http books.google.ca books?id 4B8nrDVjaCgC&pg PA417 chapter A review of the evolution of the Mozambique Belt and implications for the amalgamation and dispersal of Rodinia and Gondwana first1 G.H. last1 Grantham first2 M. last2 Maboko first3 B.M. last3 Eglington title Proterozoic East Gondwana supercontinent assembly and breakup publisher Geological Society year 2003 ISBN 1862391254 refend Category Orogeny Category Geology of Africa Category Proterozoic tectonics stub he ... more details
Unreferenced date December 2009 The Hunter Bowen Orogeny was a significant arc accretion event in the Permian and Triassic periods affecting approximately 2,500 km of the Australia n continental margin . The Hunter Bowen Orogeny occurred in two main phases, a Permian accretion of previously formed passive marginal Devonian and Carboniferous sediments in the Hunter region and mid west region of what is now New South Wales, separated by rifting, back arc volcanism and a later Permian to Triassic event resulting in arc accretion and metamorphism during a subduction event. The Hunter Bowen Orogeny has resulted in the New England Fold Belt, a tectonic accretion of metamorphic terranes and mid crustal granite granitoid intrusions, flanked by Permian to Triassic sedimentary basins which were formed distally to the now eroded orogenic mountain belt. While the Great Dividing Range north of Sydney is a prominent landform, this is more the result of Cainozoic volcanism and crustal uplift since the Jurassic than the result of the original orogenic belt which is essentially mimics. Gravity, magnetics and bathymetry indicate that several slivers of crust formerly from the Hunter Bowen orogen are now spread out across the Indo Australian plate east of the Australian continental landmass, forming some isolated submerged ocean plateaux and islands, notably Lord Howe Island . The Sydney Gunnedah Bowen Basin The Hunter Bowen event produced a 3,000 km long structural foredeep above a Late Carboniferous and Palaeozoic margin to the weakly consolidated Australian continental mass which was part of the Gondwana Supercontinent at this time the orogen developed to the east of the Palaeozoic ... See also Geology of Australia Orogeny Subduction zone Shear geology Granite particularly the section on S type and I type DEFAULTSORT Hunter Bowen Orogeny Category Geology of Australia Category Geology of New South Wales Category Permian Category Triassic Category Orogeny ... more details
that created the Great Plains . Overview The Trans Hudson orogeny was the culminating event of the Paleoproterozoic Laurentian assembly, which occurred after the Wopmay orogeny West of Hudson Bay , ca. 2.1 1.9 Ga. . The Trans Hudson orogeny resulted from the collision of the Superior craton ... change from plate margin to intraplate processes within an evolving convergent orogeny ... 2008 02 11 ref Similar to the Himalayas, the Trans Hudson orogeny was also the result of continent ... orogeny and the consequent upheaval of the continental crust in the middle Proterozoic eon caused .... During the Wopmay orogeny, subduction occurred as oceanic crust of the Slave craton was subducted beneath an eastward moving continental plate. Likewise, during the Trans Hudson orogeny, rifting at first ... mountain building orogeny . During the opening and then closure of the Manikewan Ocean, the following ... deformation and metamorphism of the Trans Hudson orogeny associated with arc arc and arc continent ... Hudsonian Orogeny. ref name Hollings cite journal author Hollings, Pete and Kevin Ansdell year 2002 ... atlas thot thot blurb.html Category Orogeny Category Cratons Category Historical geology ... more details
File Pangaea 230 million years ago .png thumb right 350px Map of Pangaea, including the Central Pangean Mountains. The Central Pangean Mountains were an extensive northeast southwest trending mountain range in the central portion of the supercontinent Pangaea during the Triassic period. They were formed as a result of collision between the minor supercontinents Laurussia and Gondwana during the formation of Pangaea. ref http science.jrank.org pages 2595 Europe.html Europe Forces That Made Europe, The Mediterranean Desert Miscellaneous regions and events ref Remnants of this massive mountain range include the Appalachian Mountains of North America and the Little Atlas of Morocco , Africa . A number of mountain building periods were involved in the formation of the Central Pangean Mountains, including the Acadian orogeny Acadian , Caledonian orogeny Caledonian and Alleghenian orogeny Alleghenian orogeny orogenies . References reflist Major African geological formations Category Mountain ranges of North America Category Mountain ranges of Africa Category Mountain ranges of Europe Category Triassic Palaeo geo stub Triassic stub ... more details
The Carolina terrane is a terrane in northwestern South Carolina , a volcanic island arc in the Southern Alleghenian orogeny . ref Dennis, Allen J., and James E. Wright 1997 , The Carolina terrane in northwestern South Carolina, U.S.A. Late Precambrian Cambrian deformation and metamorphism in a peri Gondwanan oceanic arc, Tectonics , 16 3 , pp. 460 473. ref References reflist Coord 33.5062469 81.9651152 display title Category Terranes Category Geology of South Carolina SouthCarolina stub US geology stub ... more details
, 1100&ndash 1000 Ma. Image Taconic orogeny.png thumb right 250px Taconic orogeny Caledonian orogeny the East Greenland Orogen , formed from Cryogenian to Devonian the Taconic orogeny Taconic phase in the NE U.S. and Canada during the Ordovician Period. the Acadian orogeny Acadian phase in the Eastern U.S. during Silurian and Devonian Geologic period Period s. Appalachian orogeny , usually seen as the same as the Variscan orogeny in Europe. Appalachian Mountains is a well studied orogenic belt resulting from a late Paleozoic collision between North America and Africa . Taconic orogeny Acadian orogenyAlleghenianorogeny Ouachita orogeny Ouachita Mountains of Arkansas and Oklahoma is an orogenic ...World geologic provinces The following is a list of Orogeny orogenies organised by continent country, starting with the oldest at the top. North America n orogenies Wopmay orogeny Along western edge of Canadian shield, 2100&ndash 1900 annum Ma . Trans Hudson orogeny Hudsonian orogeny or Trans Hudson orogeny Extends from Hudson Bay west into Saskatchewan then south through the western Dakotas and Nebraska ... during the Proterozoic . Lasted from 2000&ndash 1800 Ma. Penokean orogeny Wisconsin , Minnesota , and Michigan , U. S. A. and southern Ontario , Canada , 1850 1840 Ma. Big Sky orogeny Proterozoic collision between the Hearne craton and the Wyoming craton in southwest Montana, 1770 Ma. Ivanpah orogeny Mojave province, south western USA Yavapai orogeny mid to south western USA, 1760 1700 Ma. Mazatzal orogeny mid to south western USA, circa 1600 Ma. Grenville orogeny Worldwide during the late Proterozoic ... orogeny west across the Mississippi embayment Reelfoot Rift zone. Antler orogeny Ancestral ... orogeny or Ellesmerian orogeny Innuitian Mountains , Canadian Arctic, extending from Ellesmere Island to Melville Island, Canada Melville Island , Mississippian 345 Ma. Sonoma orogeny Rocky Mountains, western North America, 270&ndash 240 Ma. Nevadan orogeny Developed along western North America ... more details
The Bronson Hill Island Arc is a Bimodal volcanism bimodal volcanic terrane and associated sediments that are thought to have Accretion geology docked with Laurentia North American during the Ordovician , ca 450 Ma to create the Taconic Orogeny . These rocks are presently well exposed along the Connecticut River Valley of Vermont and New Hampshire . The arc is evidenced by plutonism and extrusive volcanics including the Ammonoosuc Formation ca. 461 Ma from Uranium lead dating U Pb zircon dates and the overlying Partridge Formation ca. 457 Ma from graptolite s in the Partridge Fm. . The docked island arc has been Metamorphism metamorphosed and deformed during the Acadian Orogeny and the Alleghenian Orogeny . References Robert H. Moench and John N. Aleinikoff, Stratigraphy, geochronology, and accretionary terrane settings of two Bronson Hill arc sequences, northern New England, Physics and Chemistry of the Earth, Parts A B CVolume 27, Issues 1 3, January 2002, Pages 47 95. Category Geology of New Hampshire Category Geology of Vermont Category Terranes US geology stub ... more details
Orphan date September 2008 The Rocky Face Fault is a geological fault responsible, in part, for the location of Cumberland Gap in the southern Appalachian mountain range . Another factor is wind gap erosion from rivers which predated the Alleghenian orogeny . Included along the fault are the towns of Middlesboro, Kentucky , Pineville, Kentucky . The fault represents a crack in the Pineville Thrust Sheet , one of many remnant resistant strata pushed upwards to the northwest over the neighboring Cumberland Plateau . Category Appalachian Mountains Category Geography of Bell County, Kentucky Category Geology of Kentucky US geology stub ... more details
the Hercynian orogeny , then the northeast of North America Alleghenianorogeny and northwest of Africa and finally in the southeast of North America Ouachita orogeny and north of South America. Name ... Laurussia during the Caledonian orogeny . The Rheic Ocean itself began to close in the Devonian when .... Jeffries, T.E. Drost, K. & Gerdes, A. year 2008 title The Cadomian Orogeny and the opening of the Rheic ... Cadomian Active Margin to Alleghenian Variscan Collision Geological Society of America Special ... more details
Refimprove date January 2009 The Pan African Ocean is a hypothesized paleo ocean whose closure created the supercontinent of Pannotia . ref cite book last Linnemann first Ulf coauthors R. Damian Nance, Petr Kraft, Gernold Zulauf title The Evolution of the Rheic Ocean From Avalonian Cadomian Active Margin to Alleghenian Variscan Collision publisher Geological Society of America year 2007 page 28 isbn 9780813724232 url http books.google.ca books?id dj9C VvmDwC&pg PA28 ref The ocean may have existed before the break up of the supercontinent of Rodinia . The ocean closed before the beginning of the Phanerozoic Eon, when the Panthalassa ocean expanded, and was eventually replaced by it. See also Pan African orogeny Mirovia References reflist Category Historical oceans Category Proterozoic palaeo geo stub nl Pan Afrikaanse Oceaan nn Det panafrikanske havet zh ... more details
period of metamorphism, faulting, and mountain building. Alleghenian The AlleghenianOrogeny occurred ... orogeny took place during the middle to late Devonian . Following the subduction of the Iapetus ... more details
Geobox Range name Bear Pond Mountains image Bearpond Mountains.jpg image size 275 image caption From left to right Kasies Knob, Two Top and Cross Mountain Pennsylvania Cross Mountain . other name country United States country1 region Pennsylvania , Maryland , highest Cross Mountain Pennsylvania Cross Mountain highest elevation imperial 2062 highest lat d highest lat m highest lat s highest lat NS highest long d highest long m highest long s highest long EW geology period Ordovician orogeny Alleghenian orogeny Alleghenian map map size The Bear Pond Mountains are a sub range in the Appalachian Mountains , that straddle Pennsylvania and Maryland in the United States . These mountains are a part of the Ridge and Valley Appalachians and reach their highest point at Cross Mountain Pennsylvania convert 2062 ft m 0 . A unique geologic feature known as the Punchbowl occurs in this range. This feature was created by the weathered shales of the Ordovician age in the center of a south plunging anticline, having been eroded to expose a large amphitheater like feature punchbowl . Cross and Hearthstone Mountain are made of hard resistant quartzite of the Tuscarora Formation of the Silurian age, which form the walls of the bowl. Whitetail Ski Resort is also located in this range on Two Top Mountain. The chief summits of the Bear Pond Mountains are the following Cross Mountain Pennsylvania convert 2062 ft m 0 Hearthstone Mountain convert 2021 ft m 0 Two Top Mountain convert 1780 ft m 0 Kasies Knob convert 1760 ft m 0 Fairview Mountain convert 1690 ft m 0 Gillians Knob convert 1575 ft m 0 Bullskin Mountain convert 1551 ft m 0 Rickard Mountain convert 1550 ft m 0 Sword Mountain convert 1500 ft m 0 Abe Mills Mountain convert 1376 ft m 0 Johnson Mountain convert 1140 ft m 0 References Alan R. Geyer 1979 Outstanding Geologic Features of Pennsylvania , Geological Survey of Pennsylvania cite web url http www.topoquest.com map.asp?lat 39.71715&lon 77.97509&datum nad27&u 4&layer DRG25&size l ... more details
A tectonic phase or deformation phase is in structural geology and petrology a phase in which tectonics tectonic movement or metamorphism took place. Tectonic phases can be extensional tectonics extensional or compressional tectonics compressional in nature. When numerous subsequent compressional tectonic phases share the same geodynamics geodynamic cause usually some plate tectonics plate tectonic mechanism this is called an orogeny . During an orogeny tectonic phases lead to mountain building , which causes deformation engineering deformation and metamorphism of rocks. In most Phanerozoic orogenies many tectonic phases are distinguished. Tectonic phases in basin geology and sedimentary rocks According to Nicolas Steno Steno s principle of original horizontality , sedimentary rock s are normally deposited as horizontal layers. When tectonic movement occurs sedimentary layers can be tilted. under such circumstances, the sedimentary plane geometry planes will have a dip geology dip an angle with a horizontal reference plane . When new sedimentary layers are deposited on top of tilted ones, they will have an angle with the older ones, a structure which is called an angular unconformity . Any angular unconformity is prove that a tectonic phase took place between the deposition of the layers below and on top of it. It is important to know if the tectonic phase was a longer event or if it was local or regional. Tectonic phases can be important events that affected large areas. The Alleghenian orogeny in North America during the Carboniferous period geology period for example can be found as an angular unconformity between rock layers in large parts of that continent. When a tectonic phase occurred while sedimentation of new sediments continued, every new layer will have a slightly different dip from the one below. The result is a sequence of sediments that wedges out in one direction. This is usually the case on the margins of basin geology geologic basins . Tectonic pha ... more details
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 commonscat Bear Valley Strip Mine The Bear Valley Strip Mine is an abandoned coal Surface mining strip mine located in Coal Township, Northumberland County, 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 . 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 Structural geology The coal and other overlying rock has been removed by mining down to a resistant sandstone bed, revealing the three dimensional structures of Fold geology folding and Fault geology faulting caused by the Alleghenian orogeny 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 ref name Nickelsen1 class wikitable Stage Deformation event I Joint geology Joint formation in coal II Joint formation with quartz fiber fillings in sandstone and ironstone III Pressure solution and primary crenulation Cleavage geology cleavage IV Conjugate wrench and wedge faults form V Large scale folding VI Extensional jointing and faulting Gallery gallery File Concretions Bear Valley.jpg Concretion s in the south wall File Bear Valley east wall.jpg View of the east wall from the Whaleback File Bear Valley Slickensides.jpg Slickensides on a fault plane, south wall. Lens cap 5.8cm wide. File Stigmaria Bear Valley upright.jpg Upright Sigill ... more details
Geobox Range name Cane Creek Mountains native name other name Bass Mountains image CaneCreekandBassMountains.JPG image caption Bass Mountain Left and Cane Creek Mountain Right , 2 of the highest peaks in the range. country United States state North Carolina state type region Alamance County region1 unit border border1 geology period orogeny Alleghenian orogeny area length 21.17 length orientation SW width 8.91 width orientation SE highest Cane Creek Mountain highest elevation 301 highest lat d 35 highest lat m 56 highest lat s 50.66 highest lat NS N highest long d 79 highest long m 26 highest long s 08.14 highest long EW W map Canecreekmap.gif map caption Location of Cane Creek Mountains in Alamance County in North Carolina map size 175 Cane Creek Mountains is a small mountain range that lies south of Burlington, North Carolina . The range covers an area including Alamance County, North Carolina Alamance County , Guilford County, North Carolina Guilford County , Randolph County, North Carolina Randolph County , and Chatham County, North Carolina Chatham County in North Carolina . Formation The mountains are typical of the rolling terrain of the Piedmont United States piedmont region of North Carolina, and are somewhat similar in formation to the nearby Caraway Mountains and Uwharrie Mountains . The Cane Creek Mountains may have formed as a part of the larger coastal range that was once the Uwharries, which are thought to have formed as a part of the Alleghenian orogeny Alleghenian or Appalachian Orogeny 300 350 million years ago during the formation and rifting of Pangaea . This earlier range is through to have had peaks more than convert 20000 ft m high, which would rival the Himalayas , the Andes , or the Alaska Range . However, erosion has worn this old mountain range down. The highest peaks of this old range are now are found in the Appalachian Mountains on the eastern coast of North America and in the Anti Atlas Anti Atlas Mountains of Morocco in Africa . The h ... more details
Hunic terrane, in North America this is called the Alleghenianorogeny , in Europe the Variscan orogeny . The Rheic Ocean had completely disappeared, and the western Paleo Tethys was closing ... Tethys Ocean was a narrow seaway. In the Early Jurassic epoch, as part of the Alpine Orogeny ... more details
Basin . They were slightly metamorphosed during the Hercynian orogeny. The sedimentary sequence ... and Recrystallization geology recrystallized during the Cadomian orogeny in the Ediacaran, 650 ... schist s and marble s rocks that were metamorphosed at high grade during the Hercynian orogeny ... 1 , pp. 1 39. aut Kroner, U. Hahn, T. Romer, R.L. & Linnemann, U. 2007 The Variscan orogeny ... Cadomian active margin to Alleghenian Variscan collision , Geological Society of America Special ... , Precambrian Research 73 , pp. 235 250. aut Matte, P. 2001 The Variscan collage and orogeny ... Hercynian orogeny nl Saxothuringische Zone ... more details
Infobox mountain name Old Rag Mountain photo Old Rag Mountain.jpg photo caption Old Rag Mountain elevation ft 3284 elevation ref ref name ngs cite ngs id AH8733 designation Old Rag Mtn accessdate 2008 11 29 ref prominence ft 1355 prominence ref ref cite web url http www.peakbagger.com peak.aspx?pid 7662 title Old Rag Mountain, Virginia publisher Peakbagger.com accessdate 2008 11 29 ref location Madison County, Virginia Madison County , Virginia , United States USA range Blue Ridge Mountains coordinates coord 38 33 06.6 N 78 18 52.3 W region US VA type mountain source ngs display inline,title coordinates ref ref name ngs topo United States Geological Survey USGS Old Rag Mountain type Granite age Precambrian first ascent easiest route Hiking Hike Old Rag Mountain is a popular hiking destination with a summit elevation of convert 3291 ft , located in the Blue Ridge Mountains of the Shenandoah National Park in Virginia s Madison County, Virginia Madison County , near Sperryville, Virginia Sperryville . In contrast to most mountains of the Blue Ridge, Old Rag has an exposed rocky summit. Geology Old Rag Mountain is underlain by Old Rag Granite, named for its ubiquitous exposure on the mountain, formed during the Grenville Orogeny about a billion years ago. About 400 million years after the Grenville orogeny during the Catoctin Formation , deposition of basaltic magma occurred during the formation of the Iapetus Ocean forming a layer of Greenschist greenstone over the granite. This was followed by the Weverton Formation , Harpers Formation , and Antietam formation in which sand and rock sedimented on the ocean floor forming quartzite and sandstone deposits. Finally a period of sedimentation of shells and skeletons of foraminifera resulted in deposition of a layer of limestone . Approximately 700 million years after the Greenville Orogeny, the Iapetus Ocean began to close resulting in the Alleghenian Orogeny when the Old Rag Granite and layers of rock deposited upon it whe ... more details
The Mississippian Mauch Chunk Formation Mmc is a mapped bedrock unit in Pennsylvania , Maryland , and West Virginia . It is named for the borough of Mauch Chunk, now known as Jim Thorpe, Pennsylvania . Description The Mauch Chunk is defined as a grayish red shale , siltstone , sandstone , and conglomerate geology conglomerate . The Loyalhanna Member is a local limestone and sandy limestone at its base, as well as the Greenbrier and Wymps Gap Members. Along the Allegheny Front , the Loyalhanna is a greenish gray, calcareous, cross bedded sandstone. ref 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. ref Depositional environment The early Mauch Chunk beds were deposited on a large basin receiving most of its sediments from distant highlands. Sea levels fluctuated and allowed some limestone deposition to occur early as well. Since the dominate color of the Mauch Chunk is red, much of the sediment was deposited above sea level in oxidizing conditions. The green colored members indicate a reducing environment characterized by frequent inundation by water either in a swamp, delta, or shallow sea. Later beds have frequent conglomerate beds signaling the first wave of the Alleghenian orogeny . ref 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. ref Fossils Plants from the division Pteridospermatophyta notably Adiantites have been identified. Some fish and worm burrows have also been observed. ref Jennings, J.R., 1985 . Fossil plants from the Mauch Chunk Formation of Pennsylvania Morphology of Adiantites Antiquus. Journal of Paleontology, v 59 n 5, p 1146 1157. ref Age Relative age dating of the Mauch Chunk places it in the late Mississippian epoch, with some of the top layers in the early Pennsylvanian epoch, being deposited between 345 ... more details
. During the AlleghenianOrogeny the rocks were pushed westward to their present location and uplifted ... and uplifted together during the Grenville Orogeny . The two ridges were later separated in the late ... more details
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