Geological period image The Cryogenian from Greek language Greek cryos cold and genesis birth is a geologic period that lasted from Mya 850 635 . It forms the second geology geologic geologic period period of the Neoproterozoic era geology Era , preceded by the Tonian Period and followed by the Ediacaran . The Sturtian and Marinoan glaciation s, ref These events were formerly considered together as the Varanger glaciations, from their first detection in Norway s Varanger Peninsula . ref which are the greatest ice ages known to have occurred on Earth and may have covered the entire planet, occurred during this period. These so called Snowball Earth snowball earth events are the subject of much ..., there is no consensus on what global event is a suitable candidate to mark the start of the Cryogenian Period, and its base is only loosely set to expr switch lc Cryogenian hadean 4567.17 archean ... calymmian 1600 ectasian 1400 stenian 1200 neoproterozoic tonian 1000 cryogenian 850 ediacaran 630 ... climate of the Cryogenian characteristic glacial deposits indicate that Earth suffered the most ... also occur in places that were at low latitudes during the Cryogenian, a phenomenon which led to the hypothesis ... www.snowballearth.org Snowball Earth theory ref Paleogeography During the Cryogenian, the supercontinent Rodinia broke up, and the supercontinent Pannotia began to form. Cryogenian biota and fossils Expand section date January 2011 Fossils of testate amoeba or Arcellinida first appear during the Cryogenian ... 2 ref During the Cryogenian period, the oldest known fossils of sponges make an appearance. ref cite journal title Fossil steroids record the appearance of Demospongiae during the Cryogenian period ... cite web title Cryogenian Period work GeoWhen Database url http www.stratigraphy.org geowhen stages ... http www.palaeos.com Proterozoic Neoproterozoic Cryogenian Cryogenian.html The Cryogenian Period Proterozoic ... ru sah simple Cryogenian sv Kryogenium vi K Cryogen zh ... more details
Varanger may refer to Varanger Peninsula of Norway Cryogenian also called Varanger glaciation disambig Short pages monitor This long comment was added to the page to prevent it being listed on Special Shortpages. It and the accompanying monitoring template were generated via Template Longcomment. Please do not remove the monitor template without removing the comment as well. ... more details
Geological era The Neoproterozoic Era is the unit of geologic time scale geologic time from 1,000 to 542.0 1.0 million years ago . ref name Ogg2008 Ogg 2008. ref The terminal Era of the formal Proterozoic Eon or the informal Precambrian , it is further subdivided into the Tonian , Cryogenian , and Ediacaran Periods. The most severe glaciation known in the geologic record occurred during the Cryogenian, when ice sheets reached the equator and formed a possible Snowball Earth . The earliest fossils of metazoa multicellular life are found in the Ediacaran , including the earliest animal s. Geology At the onset of the Neoproterozoic the supercontinent Rodinia , which had assembled during the late Mesoproterozoic , straddled the equator. During the Tonian , rifting commenced which broke Rodinia into a number of individual land masses. Possibly as a consequence of the low latitude position of most continents, several large scale glacial events occurred during the Era including the Cryogenian Sturtian and Marinoan glaciations. These glaciations are believed to have been so severe that there were ice sheets at the equator a state known as the Snowball Earth . Subdivisions The Russians divide the Siberian Neoproterozoic into the anchor Baikalian Baikalian from 850 to 650Ma loosely equivalent to the Cryogenian , which overlies the anchor Mayanian Mayanian , from 1100 to 850Ma, then the anchor Aimchanian Aimchanian . ref name Khomentovsky2008 cite journal doi 10.1016 j.rgg.2007.12.001 title Mayanian 1100 850 Ma Prebaikalian Upper Riphean of Siberia year 2008 author Khomentovsky, V journal Russian Geology and Geophysics volume 49 issue 1 pages 1 last2 Nagovitsin first2 K last3 Postnikov first3 A ref Paleobiology main Ediacaran biota The idea of the Neoproterozoic Era came on the scene relatively recently &mdash after about 1960. Nineteenth century paleontologists set the start of metazoan multicelled life at the first appearance of hard shelled animals called trilobite s and Ar ... more details
Canyon Paleobiology 26 3 360 385. Also see http www.palaeos.com Proterozoic Neoproterozoic Cryogenian Cryogenian.2.html Cryogenian ref Testate amoebae are theorized to be mostly polyphyletic coming from ... more details
Infobox lake lake name Yanisyarvi image lake caption lake image bathymetry caption bathymetry location Republic of Karelia coords coord 61 58 N 30 55 E type waterbody region RU KR display inline,title type impact crater lake inflow outflow catchment basin countries Russia length width area depth max depth volume residence time shore elevation islands cities Lake Yanisyarvi lang ru lang fi J nisj rvi is a lake in the Republic of Karelia , Russia , located north of Lake Ladoga . The basin of this somewhat circular lake was formed by meteorite impact 700 5 million years ago during the Cryogenian period. The impact crater crater is km to mi 14 in diameter. ref cite Earth Impact DB name J nisj rvi linkname janisjarvi accessdate 2009 08 19 ref Prior to World War II , the lake was thought to be the second known volcanic caldera in Finland the other was Lake Lappaj rvi . Both were eventually recognized as impact craters. References Reflist External links http earthobservatory.nasa.gov Newsroom NewImages images.php3?img id 17988 Lake J nisj rvi Impact Crater at NASA Earth Observatory Impact cratering on Earth Category Republic of Karelia cs Janisjarvi nn J nisj rvi ro Lacul Yanisyarvi ru sk Janisjarvi fi J nisj rvi ... more details
Mirovia from Russian language Russian , mirovoy , meaning global was a hypothesized superocean which may have been a global ocean surrounding the supercontinent Rodinia in the Neoproterozoic Neoproterozoic Era , about 1 billion to 750 million years ago. ref Cite book last McMenamin first Mark A. first2 Dianna L. last2 McMenamin year 1990 chapter The Rifting of Rodinia title The Emergence of Animals publisher Columbia University Press isbn 0 231 06647 3 ref The Mirovia may be essentially identical to, or the precursor of, the hypothesized Pan African Ocean , which followed the rift ing of Rodinia. The Panthalassa proto Pacific Ocean developed in the Neoproterozoic Era by subduction at the expense of the global Mirovia ocean. ref Cite book last Powell first Christopher McA last2 Pisarevsky first2 Sergei A. chapter Rodinia to Gondwanaland Growth of the Pacific Ocean and Destruction of the Mozambique and Brazilide Oceans title GSA Conference, Earth System Processes Global Meeting June 24 28, 2001 , abstract url http gsa.confex.com gsa 2001ESP finalprogram abstract 8026.htm ref Geologic evidence suggests that the middle Neoproterozoic, the Cryogenian period, was an extreme ice age so intense that Mirovia may have been completely frozen to a depth of 2 km. This is part of the Snowball Earth hypothesis. References references Category Plate tectonics Category Historical oceans Category Russian loanwords palaeo geo stub tectonics stub de Mirovia nl Mirovoi oceaan nn Mirovia pl Mirowia ru vi Mirovia ... more details
taxobox fossil range Cryogenian Cambrian regnum incertae sedis genus Nimbia species N. occlusa species authority Mikhail A. Fedonkin Fedonkin 1980 Nimbia occlusa is a form of Ediacaran Ediacaran biota fossil shaped like a circular or oval disk, with a thick rim around the margin. Within the rim the fossil is usually flat, but may have a central nipple or dimple. These fossils were generally believed to be those of cnidaria ns, but they have since been reinterpreted as structures made by microbial colonies Grazhdankin, see Ediacaran biota for references and discussion. . They can reach up to 6 cm in diameter, with a centimeter thick rim. Some fossils are distorted. Nimbia occurs in numerous locations across a large range of time, which lends weight to theories that the fossil does not represent a single animal species. It occurs in the Twitya formation in the Mackenzie Mountains in Canada dated at 610 million years ago, near the end of the Marinoan glaciation, and in ma 770 rocks in Kazakhstan. ref name Meert2010 cite doi 10.1016 j.gr.2010.11.008 ref Aspidella also appears in these areas. Morania Dubious I can t find any reference to Morania outwith the Burgess Shale date April 2009 and Beltina carbonaceous film fossils in the Twitya formation are not considered to be animals. Nimbia like fossils have also been found in the Cambrian period. References reflist cite journal author Fedonkin first MA title Novye Predstaviteli Dokembriyskikh Kishechnopolostnykh na Severe Russkoy Platformy New Precambrian Coelenterata in the North of the Russian Platform language Russian journal Paleontologicheskiy Zhurnal volume 2 pages 7 15 year 1980 External links http www.peripatus.gen.nz Taxa Cnidaria Nimbiaocclusa.html Nimbia occlusa data sheet http www.palaeos.com Proterozoic Neoproterozoic Ediacaran Ediacaran.htm Locations of Ediacaran fossils, references Category Ediacaran biota Category Cambrian life Category Prehistoric life ... more details
Series are subdivisions of stratum rock layers made based on the age of the rock and corresponding to the dating system unit called an epoch , both being formally defined international conventions of the geological timescale . A series is therefore a sequence of rock depositions defining a chronostratigraphy chronostratigraphic unit , unrelated to lithostratigraphy , which divides rock layers on their lithology phrase is jargonal non sense... speak, write in English, write for laypersons, not the intelligencia . Series are subdivisions of system geology systems and are themselves divided into stage geology stages . Series is a term defining a unit of rock layers formed in a certain interval in time it is equivalent to the term geological epoch epoch criteria defining the interval of time itself, although the two words are sometimes confused in informal literature. Series in the geological timescale Geology to Paleobiology The geological timescale has all system geology system s in the Phanerozoic eonothem subdivided into series. Some of these have their own names, in other cases a system is simply divided into a Lower, Middle and Upper series. The Cretaceous system is for example divided into the Upper Cretaceous and Lower Cretaceous series while the Carboniferous system is divided in the Pennsylvanian and Mississippian series. In 2008, the International Commission on Stratigraphy had not yet named all four series of the Cambrian . Currently series are limited to the Phanerozoic, but the ICS has stated its intention of subdividing the three systems of the Neoproterozoic Ediacaran , Cryogenian and Tonian into stages too. Systems and lithostratigraphy Systems can include many lithostratigraphic units for example formation geology formations , bed geology beds , member geology members , etc. of differing rock types that were being laid down in different environments at the same time. In the same way, a lithostratigraphic unit can include a number of systems or parts of ... more details
The East Greenland mountain range or East Greenland orogen is the linear mountain range along the eastern Greenland coast, from 70 to 82 degrees north latitude. Geology Geologically , the mountain chain consists of late Cryogenian to late Devonian 650 to 350 millions years ago fold and thrust belt s. Little is known about the exact timing and setting of the earlier tectonic phase phases as this area was later heavily Deformation geology deformed during the Caledonian Orogeny 450 to 350 million years ago . The rocks of the East Greenland orogen are mostly Silurian granites with Devonian sedimentary rocks overlying Ediacarian marine deposits, all on a basement geology basement of gneiss es. The current mountain range formed as a result of thermal isostacy thermal uplift during the opening of the Atlantic Ocean in the Cretaceous and early Tertiary starting 100 million years ago . The related Petroleum exploration in the Arctic Greenland East Greenland Rift Basin oil deposits are estimated to be one of the largest in the world. ref name Terra Daily cite web url http www.terradaily.com reports Greenland Makes Oil Companies Melt 999.html title Greenland Makes Oil Companies Melt last Allagui first Slim date July 16, 2006 publisher Agence France Presse accessdate 2008 08 31 ref References Reflist http www.cprm.gov.br 33IGC 1386156.html Caledonian orogeny on Eastern Greenland http www.britannica.com EBchecked topic 176631 East Greenland orogen Britannica Encyclopedia article of East Greenland orogen http nora.nerc.ac.uk 6086 Abstract of the paper Foreland propagating Caledonian thrust systems in East Greenland Category Orogeny Category Geology of Greenland Greenland stub regional geology stub ... more details
Orphan date February 2011 infobox rockunit age Geological range 635 577 period Ediacaran location South China The Lantian formation is a 150 m thick sequence of rocks deposited in southern China over around 90 million years in the Ediacaran period. ref name Narbonne2011 cite doi 10.1038 470339a ref Its algal macrofossil s are the oldest large and complex fossils known. ref name Narbonne2011 Sedimentology The rocks were deposited in shallow seas, in the photic zone yet below storm wave base , ref doi 10.1038 nature09810 yet were deposited in predominantly Dead zone ecology anoxic conditions . The fossils are located on the bedding planes, and are randomly oriented. ref name Narbonne2011 The lowest part of the formation consists of a cap dolostone , marking the end of the Marinoan glaciation and start of the Ediacaran. Above this is black shale containing the Lantian biota fossils. Above this are layers of dolomite, and shale followed by limestone. The highest part of the formation is black shale again. Above the formation is the Piyuancun formation consisting of silicious rock. The Lantian formation overlies diamictite from the Cryogenian . ref http www.nature.com nature journal v470 n7334 extref nature09810 s1.pdf supplementary figure 4 of doi 10.1038 nature09810 ref Taphonomy The fossils are preserved as carbonaceous films in a Burgess Shale type preservation al fashion. ref name Narbonne2011 Age Originally presumed to be Cambrian in age, ref name Narbonne2011 the formation is now correlated with the Doushantuo formation , with an overlying formation also falling in the Ediacaran period. ref doi 10.1038 nature09810 References reflist Category Ediacaran biota Category Paleontological sites of Asia ... more details
period color pal ozoic Periods bar3 text Cryogenian bar3 to 635 bar3 left .1 bar3 colour period color cryogenian Dividing line bar23 from 635.3 bar23 to 634.7 bar23 colour black bar23 left 0.1 bar4 ... more details
File Siberian craton location.jpg thumb current location in Asia Siberia is the craton located in the heart of the region of Siberia . Siberia or Angaraland or simply Angara is today the Central Siberian Plateau . It is an extremely ancient craton that formed an independent continent before the Permian period. Partial history of Siberia in chronological order 2.5 billion years ago Siderian , Siberia was part of a continent of Arctica , along with the Canadian Shield 1.1 billion years ago Stenian , Siberia became part of the major supercontinent of Rodinia . 750 million years ago Cryogenian , Rodinia broke up, and Siberia became part of the minor supercontinent of Protolaurasia . 600 million years ago Ediacaran , Protolaurasia became part of the major southern supercontinent of Pannotia . 550 million years ago Ediacaran , Pannotia broke up and Protolaurasia split up and became the continents of Laurentia , Baltica , and Siberia. Cambrian , Siberia was an independent continent. Carboniferous , Siberia collided with the minor continent of Kazakhstania . Permian , Siberia, and Kazakhstania collided with Baltica , thus completing the formation of the supercontinent Pangaea . Siberian Traps formed. Jurassic , Pangaea split up into the two minor supercontinents of Gondwana and Laurasia . Cretaceous , Laurasia gradually split up into the 2 continents of North America and Eurasia . Eocene , The minor continent of India collided into Asia , generating the Himalaya . Present day, Siberia is part of the continent of Asia which is part of Eurasia . 250 million years sith, Siberia may be in the subtropical region and part of a new supercontinent of Pangaea Ultima . 400 million years sith, Pangaea Ultima may disintegrate, but Siberia may remain attached to Eurasia. External links http jan.ucc.nau.edu rcb7 paleogeographic asia.html Asia History Page detailing the history of Siberia as well as other parts of Asia. Continents of the world Category Historical continents Category Tecto ... more details
Automatic taxobox taxon Demospongiae image Barrel6.jpg image caption Barrel sponge Xestospongia testudinaria authority William Johnson Sollas Sollas , 1885 subdivision ranks Subclasses display children 1 The Demospongiae are the largest Class biology class in the phylum Porifera . Their skeletons are made of spicules consisting of fibers of the protein spongin , the mineral silica , or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar Hexactinellida glass sponges . ref name IZ cite book author Barnes, Robert D. year 1982 title Invertebrate Zoology publisher Holt Saunders International location Philadelphia, PA pages 105 106 isbn 0 03 056747 5 ref The demosponges include 90 of all species of sponges and are predominantly Sponge Water flow and body structures leuconoid in structure. There are many diverse Order biology orders in this class, including all of the large sponges. Most are marine dwellers, but several live in freshwater environments. Some species are brightly colored, and there is great variety in body shape the largest species are over convert 1 m ft across. ref name IZ They reproduce both sex ually and asexual reproduction asexually . Classification The Demospongia have an ancient history with the first demosponge fossil s appearing in Precambrian deposits at the end of the Cryogenian Snowball Earth period, where their presence has been detected by fossilized steroids, called sterane s, hydrocarbon markers that are characteristic of the cell membranes of the sponges, rather than from direct fossils of the sponges themselves. They represent a continuous 100 Myr long chemical fossil record of demosponges through the end of the Neoproterozoic . ref Gordon D, Love et al. , Fossil steroids record the appearance of Demospongiae during the Cryogenian period , Nature , 2009 ref The earliest sponge bearing reef s date to the Early Cambrian, ref They are the earliest known reef structure built by animals. r ... more details
radiation of acritarch s. Rodinia starts to break up. 850 Ma Cryogenian period starts, during which ... Cryogenian 850 Ma s cryogenic freezing making In this period all the Earth froze over Ediacaran 635 ... more details
Geological eon Image Stromatolites Cochabamba.jpg thumb right 330px Lower Proterozoic Stromatolites from Bolivia, South America The Proterozoic pron en pro t r zo k is a eon geology geological eon representing a period before the first abundant complex life on Earth . The name Proterozoic comes from the Greek earlier life . The Proterozoic Eon extended from 2500 annum Ma to 542.0 1.0 Ma million years ago , and is the most recent part of the old, informally named Precambrian time. The Proterozoic consists of 3 geologic era geology era s, from oldest to youngest Paleoproterozoic Mesoproterozoic Neoproterozoic The well identified events were The transition to an oxygen ated atmosphere during the Mesoproterozoic . Several glacier glaciations , including the hypothesized Snowball Earth during the Cryogenian period in the late Neoproterozoic . The Ediacaran Period 635 to 542 Ma which is characterized by the evolution of abundant soft bodied multicellular organisms. The Proterozoic record The geologic record of the Proterozoic is much better than that for the preceding Archean . In contrast to the deep water deposits of the Archean, the Proterozoic features many stratum strata that were laid down in extensive shallow Epeiric Sea epicontinental seas furthermore, many of these rocks are less Metamorphic rock metamorphosed than Archean age ones, and plenty are unaltered. ref cite book last Stanley first Steven M. title Earth System History location New York publisher W.H. Freeman and Company year 1999 isbn 0 7167 2882 6 pages 315 ref Study of these rocks shows that the eon featured massive, rapid continent al accretion unique to the Proterozoic , supercontinent cycle s, and wholly modern orogeny orogenic activity. ref Stanley, 315 18, 329 32 ref The first known glaciations occurred during the Proterozoic one began shortly after the beginning of the eon, while there were at least four during the Neoproterozoic, climaxing with the Snowball Earth of the Varangian glaciation. ... more details
infobox rockunit image Doushantou Embryo Yinetal2007.jpg caption A purported Ediacarian embryo contained within an acritarch from the Doushantuo formation location South China period Ediacaran age geo range 635 551 ref ref name Jiang2011 cite doi 10.1016 j.gr.2011.01.006 ref The Doushantuo Formation zh c p d u sh n tu is a lagerst tten Lagerst tte in Guizhou Province, China that is notable for being one of the oldest fossil beds to contain highly preserved fossils. The formation is of particular interest because it appears to cover the boundary between the problematic organisms of the Ediacaran geological period and the more familiar fauna of the Cambrian explosion of lifeforms whose descendents are recognizable. Taken as a whole, the Doushantuo Formation ranges from about 590 Ma at its base to about 565 Ma at its top, predating by perhaps five million years Ma the earliest of the classical Ediacaran faunas from Mistaken Point , Newfoundland island Newfoundland , and recording conditions a good forty to fifty million years before the Cambrian explosion. Sedimentology The whole sequence sits on an unconformity with the underlying Liantuo Formation , which is free of fossils, an unconformity usually being interpreted as a period of erosion. On that unconformity lie tillite s, the Nantuo Formation of cemented glacial till formed of glacial deposits of cobbles and gravel laid down at the end of the Cryogenian glaciation Snowball Earth . This glacial level is tentatively dated ca 610 590 Ma. The Doushantuo formation itself has three layers representing aquatic sediments that formed as sea levels rose with the melting of worldwide glaciation. Biomarker s indicate highly saline conditions, such as might be found in a lagoon, low oxygen levels, and very little sediment that had been washed off land surfaces. The richest finds the Lagerst tte itself lie at the bottom of the middle stratum, with a date about 570 Ma. Fossils See Fossil embryos Doushantuo fossils are all a ... more details
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. Result of the collision of the Superior craton with the Hearne craton and the Wyoming craton 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 , 1300&ndash 1000 Ma. Associated with the assembly of the supercontinent Rodinia . Formed folded mountains in Eastern North America from Newfoundland and Labrador Newfoundland to North Carolina , 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 orogeny Alleghenian orogeny Ouachita orogeny Ouachita Mountains of Arkansas and Oklahoma is an orogenic belt that dates from the late Paleozoic Era geology Era and is most likely a continuation of ... more details
Calibrating the Cryogenian which concluded that Ice was therefore grounded below sea level at very ... www.sciencemag.org cgi content abstract 327 5970 1241 Calibrating the Cryogenian , Abstract only Ice ... are associated with Cryogenian glacial deposits. For such iron rich rocks to be deposited there would ... Earth during the Cryogenian Period. Around the top of Neoproterozoic glacial deposits there is commonly ... the magnitude of cooling. During the Cryogenian period, however, the Earth s continents were all ... more details
ago the so called Snowball Earth of the Cryogenian period geology period and the rapid evolution of primitive ... influence the marine life of its time. In the Cryogenian period the Earth experienced large glaciation ... more details
from the Cryogenian , as well as the global warming that occurred at the start of the Ediacaran .... Granite intruded Ma 760 in the Cryogenian. The granite contains inherited zircon s from Ma 1800 ... in the Cryogenian Ma 780 was intruded by granite Bowry granitoids Ma 777 . These have been metamorphosed ... of Cryogenian and on into the Ediacaran and Cambrian. The Togari group contains greywacke, conglomerate ... between the Cryogenian and Ediacaran periods as they contain volcanics that can be dated ... Inlier and the Dundas Inlier. The Success Creek Group from the Cryogenian has diamictite, quartz ... dropstones are found in the interbedding, suggesting Cryogenian age, however carbon isotope results ... more details
Encyclopedia
top
