banner



Home  ›  What Was The Chemical Makeup Of The Atmosphere In The Ordovician Period

What Was The Chemical Makeup Of The Atmosphere In The Ordovician Period

Written By Tuesday, April 12, 2022 Add Comment Edit

2nd menses of the Paleozoic Era 485-444 meg years ago

Ordovician
485.iv ± 1.nine – 443.8 ± 1.five Ma

PreꞒ

Ꞓ

O

South

D

C

P

T

J

1000

Pg

Northward
Chronology
Etymology
Name formality Formal
Proper noun ratified 1960
Usage information
Angelic body Earth
Regional usage Global (ICS)
Time calibration(s) used ICS Time Scale
Definition
Chronological unit Period
Stratigraphic unit System
First proposed past Charles Lapworth, 1879
Fourth dimension span formality Formal
Lower boundary definition FAD of the Conodont Iapetognathus fluctivagus
Lower boundary GSSP Greenpoint section, Dark-green Point, Newfoundland, Canada
49°xl′58″N 57°57′55″W  /  49.6829°N 57.9653°W  / 49.6829; -57.9653
GSSP ratified 2000[5]
Upper boundary definition FAD of the Graptolite Akidograptus ascensus
Upper boundary GSSP Dob'due south Linn, Moffat, U.Grand.
55°26′24″N 3°16′12″W  /  55.4400°Northward 3.2700°W  / 55.4400; -3.2700
GSSP ratified 1984[6] [seven]
Atmospheric and climatic information
Body of water level above present day 180 m; rising to 220 m in Caradoc and falling sharply to 140 m in finish-Ordovician glaciations[8]

The Ordovician ( or-də-VISH-ee-ən, -⁠doh-, -⁠VISH-ən)[9] is a geologic catamenia and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.vi 1000000 years from the cease of the Cambrian Menses 485.4 million years agone (Mya) to the first of the Silurian Period 443.8 Mya.[10]

The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively.[xi] Lapworth recognized that the fossil creature in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a organisation of their ain. The Ordovician received international approving in 1960 (40 years after Lapworth'due south death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress.

Life continued to flourish during the Ordovician equally it did in the earlier Cambrian Period, although the end of the flow was marked by the Ordovician–Silurian extinction events. Invertebrates, namely molluscs and arthropods, dominated the oceans, with members of the latter group probably starting their establishment on state during this time, becoming fully established past the Devonian. The first land plants are known from this period. The Great Ordovician Biodiversification Event considerably increased the diversity of life. Fish, the world's first true vertebrates, continued to evolve, and those with jaws may accept offset appeared belatedly in the period. Nigh 100 times equally many meteorites struck the Earth per year during the Ordovician compared with today.[12]

Subdivisions [edit]

A number of regional terms take been used to subdivide the Ordovician Period. In 2008, the ICS erected a formal international organisation of subdivisions.[13] In that location be Baltoscandic, British, Siberian, North American, Australian, Chinese Mediterranean and Northward-Gondwanan regional stratigraphic schemes.[14]

The Ordovician Catamenia in United kingdom was traditionally broken into Early (Tremadocian and Arenig), Centre (Llanvirn (subdivided into Abereiddian and Llandeilian) and Llandeilo) and Belatedly (Caradoc and Ashgill) epochs. The respective rocks of the Ordovician System are referred to every bit coming from the Lower, Middle, or Upper office of the column. The faunal stages (subdivisions of epochs) from youngest to oldest are:

Late Ordovician

  • Hirnantian stage/Gamach (Ashgill)
  • Rawtheyan/Richmond (Ashgill)
  • Cautleyan/Richmond (Ashgill)
  • Pusgillian/Maysville/Richmond (Ashgill)

Centre Ordovician

  • Trenton (Caradoc)
  • Onnian/Maysville/Eden (Caradoc)
  • Actonian/Eden (Caradoc)
  • Marshbrookian/Sherman (Caradoc)
  • Longvillian/Sherman (Caradoc)
  • Soudleyan/Kirkfield (Caradoc)
  • Harnagian/Rockland (Caradoc)
  • Costonian/Black River (Caradoc)
  • Chazy (Llandeilo)
  • Llandeilo (Llandeilo)
  • Whiterock (Llanvirn)
  • Llanvirn (Llanvirn)

Early on Ordovician

  • Cassinian (Arenig)
  • Arenig/Jefferson/Castleman (Arenig)
  • Tremadoc/Deming/Gaconadian (Tremadoc)

British stages [edit]

The Tremadoc corresponds to the (modern) Tremadocian. The Floian corresponds to the lower Arenig; the Arenig continues until the early Darriwilian, subsuming the Dapingian. The Llanvirn occupies the rest of the Darriwilian, and terminates with it at the base of the Belatedly Ordovician. The Sandbian represents the first half of the Caradoc; the Caradoc ends in the mid-Katian, and the Ashgill represents the last half of the Katian, plus the Hirnantian.[15]

Ordovician regional stages
ICS Epoch ICS stage British epoch British stage Due north American epoch Due north American stage Australian epoch Australian stage Chinese epoch Chinese phase
Late Ordovician Hirnantian stage Ashgill series Hirnantian stage Cincinnati series Gamach stage Late Ordovician Bolinda phase Late Ordovician Hirnantian stage
Katian stage Rawthey stage Richmond stage Chientangkiang stage
Cautley phase Maysville stage Easton stage Neichiashan stage
Pusgill phase Eden stage
Caradoc series Strefford stage Mohawk stage Chatfield stage
Cheney stage
Sandbian stage Burrell stage Turin stage Gisborne stage
Aureluc phase Whiterock stage Chazy stage
Middle Ordovician Darriwilian stage Llanvirn series Llandeilo phase Eye Ordovician Darriwilian stage Center Ordovician Darriwilian phase
Abereiddy stage Not defined
Dapingian phase Arenig series Fenn stage Early Ordovician Yapeen stage Dapingian phase
Whitland stage Ranger stage Castlemaine phase
Ibex series Black Hills phase Chewton stage
Bendigo stage
Early on Ordovician Floian stage Moridun stage Tule stage Lancefield stage Early Ordovician Floian stage
Tremadocian stage Tremadoc serial Migneint stage Stairs stage Tremadocian stage
Cressage stage Skullrock stage

Paleogeography and tectonics [edit]

Paleogeographic map of the Earth in the centre Ordovician, 470 1000000 years ago

During the Ordovician, the southern continents were assembled into Gondwana, which reached from due north of the equator to the Southward Pole. The Panthalassic Ocean, centered in the northern hemisphere, covered over one-half the globe.[16] At the start of the period, the continents of Laurentia (in present-day Northward America), Siberia, and Baltica (present-day northern Europe) were separated from Gondwana by over 5,000 kilometres (iii,100 mi) of ocean. These smaller continents were also sufficiently widely separated from each other to develop singled-out communities of benthic organisms.[17] The minor continent of Avalonia had just rifted from Gondwana and began to movement north towards Baltica and Laurentia, opening the Rheic Sea betwixt Gondwana and Avalonia.[18] [nineteen] [twenty] Avalonia collided with Baltica towards the end of Ordovician.[21]

Other geographic features of the Ordovician world included the Tornquist Ocean, which separated Avalonia from Baltica;[17] the Aegir Bounding main, which separated Baltica from Siberia;[22] and an oceanic area between Siberia, Baltica, and Gondwana which expanded to become the Paleoasian Sea in Carboniferous time. The Mongol-Okhotsk Ocean formed a deep embayment between Siberia and the Central Mongolian terranes. Near of the terranes of central Asia were part of an equatorial archipelago whose geometry is poorly constrained past the available evidence.[23]

The period was i of extensive, widespread tectonism and volcanism. However, orogenesis (mountain-building) was not primarily due to continent-continent collisions. Instead, mountains arose along agile continental margins during accession of arc terranes or ribbon microcontinents. Accession of new crust was limited to the Iapetus margin of Laurentia; elsewhere, the design was of rifting in dorsum-arc basins followed by remerger. This reflected episodic switching from extension to compression. The initiation of new subduction reflected a global reorganization of tectonic plates centered on the affiliation of Gondwana.[24] [17]

The Taconic orogeny, a major mount-edifice episode, was well under way in Cambrian times.[25] This continued into the Ordovician, when at to the lowest degree two volcanic isle arcs collided with Laurentia to class the Appalachian Mountains. Laurentia was otherwise tectonically stable. An island arc accreted to S Prc during the period, while subduction along north Communist china (Sulinheer) resulted in the emplacement of ophiolites.[26]

The ash fall of the Millburg/Big Bentonite bed, at about 454 Ma, was the largest in the last 590 million years. This had a dense stone equivalent volume of every bit much as i,140 cubic kilometres (270 cu mi). Remarkably, this appears to have had little impact on life.[27]

In that location was vigorous tectonic activity along northwest margin of Gondwana during the Floian, 478 Ma, recorded in the Central Iberian Zone of Kingdom of spain. The activity reached equally far as Turkey past the end of Ordovician. The opposite margin of Gondwana, in Australia, faced a ready of isle arcs.[17] The accretion of these arcs to the eastern margin of Gondwana was responsible for the Benambran Orogeny of eastern Commonwealth of australia.[28] [29] Subduction also took place along what is at present Argentina (Famatinian Orogeny) at 450 Ma.[30] This involved pregnant dorsum arc rifting.[17] The interior of Gondwana was tectonically repose until the Triassic.[17]

Towards the end of the period, Gondwana began to drift beyond the Due south Pole. This contributed to the Hibernian glaciation and the associated extinction result.[31]

Ordovician meteor effect [edit]

The Ordovician shooting star consequence is a proposed shower of meteors that occurred during the Middle Ordovician Epoch, nigh 467.v ± 0.28 million years ago, due to the break-upwards of the 50 chondrite parent body.[32] It is not associated with whatsoever major extinction event.[33] [34] [35]

Geochemistry [edit]

External mold of Ordovician bivalve showing that the original aragonite shell dissolved on the ocean flooring, leaving a cemented mold for biological encrustation (Waynesville Formation of Franklin Canton, Indiana).

The Ordovician was a fourth dimension of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus very common, forth with calcitic ooids, calcitic cements, and invertebrate faunas with dominantly calcitic skeletons. Biogenic aragonite, like that composing the shells of well-nigh molluscs, dissolved rapidly on the sea floor later on death.[36] [37]

Different Cambrian times, when calcite production was dominated by microbial and not-biological processes, animals (and macroalgae) became a ascendant source of calcareous textile in Ordovician deposits.[38]

Climate and bounding main level [edit]

The early Ordovician climate was very hot, with intense greenhouse atmospheric condition giving mode to a more than temperate climate in the Heart Ordovician. Further cooling led to the Late Ordovician glaciation.[39] [40] The Ordovician saw the highest sea levels of the Paleozoic, and the low relief of the continents led to many shelf deposits being formed under hundreds of metres of water.[38] The sea level rose more than or less continuously throughout the Early on Ordovician, leveling off somewhat during the center of the period.[38] Locally, some regressions occurred, simply the sea level rise connected in the beginning of the Late Ordovician. Ocean levels fell steadily due to the cooling temperatures for nearly xxx 1000000 years leading up to the Hirnantian glaciation. During this icy stage, sea level seems to have risen and dropped somewhat. Despite much written report, the details remain unresolved.[38] In particular, some researches interpret the fluctuations in sea level every bit pre-Hibernian glaciation,[41] just sedimentary evidence of glaciation is lacking until the end of the flow.[21] There is too evidence that global temperatures rose briefly in the early Katian (Boda Event), depositing bioherms and radiating animal across Europe.[42]

Every bit with North America and Europe, Gondwana was largely covered with shallow seas during the Ordovician. Shallow clear waters over continental shelves encouraged the growth of organisms that deposit calcium carbonates in their shells and hard parts. The Panthalassic Bounding main covered much of the Northern Hemisphere, and other pocket-size oceans included Proto-Tethys, Paleo-Tethys, Khanty Ocean, which was closed off by the Late Ordovician, Iapetus Body of water, and the new Rheic Ocean.

As the Ordovician progressed, in that location is evidence of glaciers on the land we now know as Africa and South America, which were nearly the South Pole at the time, resulting in the ice caps of the Late Ordovician glaciation.

Life [edit]

A diorama depicting Ordovician flora and creature.

For nigh of the Late Ordovician life continued to flourish, only at and nearly the terminate of the period there were mass-extinction events that seriously affected conodonts and planktonic forms like graptolites. The trilobites Agnostida and Ptychopariida completely died out, and the Asaphida were much reduced. Brachiopods, bryozoans and echinoderms were as well heavily affected, and the endocerid cephalopods died out completely, except for possible rare Silurian forms. The Ordovician–Silurian extinction events may have been caused by an ice age that occurred at the end of the Ordovician Period, due to the expansion of the first terrestrial plants,[43] equally the finish of the Late Ordovician was 1 of the coldest times in the last 600 meg years of Earth's history.

Brute [edit]

Fossiliferous limestone slab from the Freedom Germination (Upper Ordovician) of Caesar Creek State Park near Waynesville, Ohio.

On the whole, the fauna that emerged in the Ordovician were the template for the remainder of the Palaeozoic.[38] The animal was dominated by tiered communities of suspension feeders, mainly with brusk food chains. The ecological arrangement reached a new course of complexity far beyond that of the Cambrian fauna,[38] which has persisted until the present solar day.[38]

Though less famous than the Cambrian explosion, the Ordovician radiation (also known as the Great Ordovician Biodiversification Consequence)[17] was no less remarkable; marine faunal genera increased fourfold, resulting in 12% of all known Phanerozoic marine beast.[44] Another modify in the animate being was the strong increase in filter-feeding organisms.[45] The trilobite, inarticulate brachiopod, archaeocyathid, and eocrinoid faunas of the Cambrian were succeeded by those that dominated the rest of the Paleozoic, such as clear brachiopods, cephalopods, and crinoids. Articulate brachiopods, in particular, largely replaced trilobites in shelf communities.[46] Their success epitomizes the greatly increased diversity of carbonate beat-secreting organisms in the Ordovician compared to the Cambrian.[46]

Ordovician geography had its effect on the multifariousness of fauna. The widely separated continents of Laurentia and Baltica developed distinct trilobite fauna from the trilobite fauna of Gondwana, and Gondwana adult distinct animal in its tropical and temperature zones. However, tropical clear brachiopods had a more than cosmopolitan distribution, with less variety on dissimilar continents. Faunas get less provincial later in the Ordovician, though they were still distinguishable into the late Ordovician.[47]

In Northward America and Europe, the Ordovician was a fourth dimension of shallow continental seas rich in life. Trilobites and brachiopods in particular were rich and diverse. Although solitary corals engagement back to at least the Cambrian, reef-forming corals appeared in the early on Ordovician, corresponding to an increase in the stability of carbonate and thus a new abundance of calcifying animals.[38]

Molluscs, which appeared during the Cambrian or even the Ediacaran, became mutual and varied, especially bivalves, gastropods, and nautiloid cephalopods. Cephalopods diversified from shallow marine tropical environments to dominate almost all marine environments.[48]

At present-extinct marine animals chosen graptolites thrived in the oceans. This includes the distinctive Nemagraptus gracilis graptolite fauna, which was distributed widely during pinnacle sea levels in the Sandbian.[49] [21] [21] Some new cystoids and crinoids appeared.

It was long thought that the starting time true vertebrates (fish — Ostracoderms) appeared in the Ordovician, but contempo discoveries in China reveal that they probably originated in the Early on Cambrian.[ citation needed ] The first gnathostome (jawed fish) appeared in the Tardily Ordovician Epoch.

During the Middle Ordovician there was a large increment in the intensity and diversity of bioeroding organisms. This is known as the Ordovician Bioerosion Revolution.[50] Information technology is marked by a sudden abundance of hard substrate trace fossils such as Trypanites, Palaeosabella, Petroxestes and Osprioneides. Several groups of endobiotic symbionts appeared in the Ordovician.[51] [52]

In the Early Ordovician, trilobites were joined by many new types of organisms, including tabulate corals, strophomenid, rhynchonellid, and many new orthid brachiopods, bryozoans, planktonic graptolites and conodonts, and many types of molluscs and echinoderms, including the ophiuroids ("brittle stars") and the first sea stars. Nevertheless, the arthropods remained abundant, all the Late Cambrian orders continued, and were joined past the new group Phacopida. The first evidence of state plants too appeared (come across evolutionary history of life).

In the Middle Ordovician, the trilobite-dominated Early Ordovician communities were replaced by generally more mixed ecosystems, in which brachiopods, bryozoans, molluscs, cornulitids, tentaculitids and echinoderms all flourished, tabulate corals diversified and the offset rugose corals appeared. The planktonic graptolites remained diverse, with the Diplograptina making their appearance. Bioerosion became an important process, especially in the thick calcitic skeletons of corals, bryozoans and brachiopods, and on the all-encompassing carbonate hardgrounds that appear in abundance at this time. One of the earliest known armoured agnathan ("ostracoderm") vertebrate, Arandaspis, dates from the Middle Ordovician.

Trilobites in the Ordovician were very dissimilar from their predecessors in the Cambrian. Many trilobites developed baroque spines and nodules to defend confronting predators such as primitive eurypterids and nautiloids while other trilobites such as Aeglina prisca evolved to become swimming forms. Some trilobites even developed shovel-similar snouts for ploughing through muddy sea bottoms. Some other unusual clade of trilobites known as the trinucleids developed a broad pitted margin around their caput shields.[53] Some trilobites such as Asaphus kowalewski evolved long eyestalks to assist in detecting predators whereas other trilobite eyes in contrast disappeared completely.[54] Molecular clock analyses suggest that early arachnids started living on land by the end of the Ordovician.[55]

The earliest-known octocorals date from the Ordovician.[56]

  • Upper Ordovician edrioasteroid Cystaster stellatus on a cobble from the Kope Formation in northern Kentucky with the cyclostome bryozoan Corynotrypa in the background

  • Middle Ordovician fossiliferous shales and limestones at Fossil Mountain, west-central Utah

  • Outcrop of Upper Ordovician rubbly limestone and shale, southern Indiana

  • Outcrop of Upper Ordovician limestone and small shale, primal Tennessee

  • Bryozoan fossils in Ordovician kukersite oil shale, northern Republic of estonia

  • Vinlandostrophia ponderosa, Maysvillian (Upper Ordovician) most Madison, Indiana (scale bar is 5.0 mm)

  • Prasopora, a trepostome bryozoan from the Ordovician of Iowa

  • An Ordovician strophomenid brachiopod with encrusting inarticulate brachiopods and a bryozoan

  • The heliolitid coral Protaraea richmondensis encrusting a gastropod; Cincinnatian (Upper Ordovician) of southeastern Indiana

  • Zygospira modesta, atrypid brachiopods, preserved in their original positions on a trepostome bryozoan from the Cincinnatian (Upper Ordovician) of southeastern Indiana

  • Graptolites (Amplexograptus) from the Ordovician near Caney Springs, Tennessee

Flora [edit]

Green algae were common in the Late Cambrian (perhaps earlier) and in the Ordovician. Terrestrial plants probably evolved from green algae, first appearing equally tiny non-vascular forms resembling liverworts, in the centre to belatedly Ordovician.[58] Fossil spores found in Ordovician sedimentary rock are typical of bryophytes.[59]

Colonization of land would take been limited to shorelines

Amidst the first land fungi may have been arbuscular mycorrhiza fungi (Glomerales), playing a crucial part in facilitating the colonization of land by plants through mycorrhizal symbiosis, which makes mineral nutrients bachelor to plant cells; such fossilized fungal hyphae and spores from the Ordovician of Wisconsin have been found with an age of virtually 460 million years ago, a time when the land flora most likely only consisted of plants similar to not-vascular bryophytes.[60]

Cease of the menstruum [edit]

The Ordovician came to a close in a serial of extinction events that, taken together, comprise the second largest of the v major extinction events in Globe's history in terms of percentage of genera that became extinct. The only larger one was the Permian–Triassic extinction event.

The extinctions occurred approximately 447–444 one thousand thousand years ago and mark the boundary between the Ordovician and the following Silurian Period. At that time all complex multicellular organisms lived in the bounding main, and about 49% of genera of fauna disappeared forever; brachiopods and bryozoans were greatly reduced, forth with many trilobite, conodont and graptolite families.

The most commonly accepted theory is that these events were triggered by the onset of cold atmospheric condition in the late Katian, followed past an ice age, in the Hirnantian faunal stage, that concluded the long, stable greenhouse conditions typical of the Ordovician.

The ice age was peradventure not long-lasting. Oxygen isotopes in fossil brachiopods prove its duration may have been merely 0.5 to 1.five million years.[61] Other researchers (Page et al.) estimate more than temperate conditions did not render until the tardily Silurian.

The tardily Ordovician glaciation event was preceded past a fall in atmospheric carbon dioxide (from 7000 ppm to 4400 ppm).[62] [63] The dip may have been acquired by a burst of volcanic activity that deposited new silicate rocks, which depict COtwo out of the air every bit they erode.[63] Another possibility is that bryophytes and lichens, which colonized state in the centre to late Ordovician, may have increased weathering enough to draw downwardly COii levels.[58] The drib in CO2 selectively affected the shallow seas where most organisms lived. As the southern supercontinent Gondwana drifted over the South Pole, ice caps formed on information technology, which have been detected in Upper Ordovician rock strata of North Africa and so-next northeastern Southward America, which were south-polar locations at the fourth dimension.

As glaciers grew, the ocean level dropped, and the vast shallow intra-continental Ordovician seas withdrew, which eliminated many ecological niches. When they returned, they carried diminished founder populations that lacked many whole families of organisms. They then withdrew again with the next pulse of glaciation, eliminating biological multifariousness with each change.[64] Species limited to a single epicontinental sea on a given landmass were severely afflicted.[37] Tropical lifeforms were hitting especially hard in the kickoff wave of extinction, while cool-h2o species were hit worst in the second pulse.[37]

Those species able to adapt to the changing weather condition survived to fill up the ecological niches left past the extinctions. For case, there is evidence the oceans became more securely oxygenated during the glaciation, assuasive unusual benthic organisms (Hirnantian fauna) to colonize the depths. These organisms were cosmopolitan in distribution and present at most latitudes.[47]

At the terminate of the 2d event, melting glaciers acquired the sea level to rise and stabilise once again. The rebound of life's diversity with the permanent re-flooding of continental shelves at the onset of the Silurian saw increased biodiversity within the surviving Orders. Recovery was characterized past an unusual number of "Lazarus taxa", disappearing during the extinction and reappearing well into the Silurian, which suggests that the taxa survived in small numbers in refugia.[65]

An alternate extinction hypothesis suggested that a ten-2nd gamma-ray burst could have destroyed the ozone layer and exposed terrestrial and marine surface-domicile life to deadly ultraviolet radiation and initiated global cooling.[66]

Contempo work because the sequence stratigraphy of the Belatedly Ordovician argues that the mass extinction was a single protracted episode lasting several hundred grand years, with abrupt changes in water depth and sedimentation charge per unit producing two pulses of concluding occurrences of species.[67]

References [edit]

  1. ^ Wellman, C.H.; Gray, J. (2000). "The microfossil record of early land plants". Phil. Trans. R. Soc. B. 355 (1398): 717–732. doi:10.1098/rstb.2000.0612. PMC1692785. PMID 10905606.
  2. ^ Korochantseva, Ekaterina; Trieloff, Mario; Lorenz, Cyrill; Buykin, Alexey; Ivanova, Marina; Schwarz, Winfried; Hopp, Jens; Jessberger, Elmar (2007). "L-chondrite asteroid breakup tied to Ordovician meteorite shower by multiple isochron twoscore Ar- 39 Ar dating". Meteoritics & Planetary Science. 42 (one): 113–130. Bibcode:2007M&PS...42..113K. doi:x.1111/j.1945-5100.2007.tb00221.x.
  3. ^ Lindskog, A.; Costa, M. M.; Rasmussen, C.Thou.Ø.; Connelly, J. N.; Eriksson, M. E. (2017-01-24). "Refined Ordovician timescale reveals no link between asteroid breakup and biodiversification". Nature Communications. 8: 14066. doi:x.1038/ncomms14066. ISSN 2041-1723. PMC5286199. PMID 28117834. It has been suggested that the Middle Ordovician meteorite battery played a crucial part in the Great Ordovician Biodiversification Issue, but this report shows that the two phenomena were unrelated
  4. ^ "Nautical chart/Time Scale". world wide web.stratigraphy.org. International Commission on Stratigraphy.
  5. ^ Cooper, Roger; Nowlan, Godfrey; Williams, Due south. H. (March 2001). "Global Stratotype Section and Indicate for base of the Ordovician System" (PDF). Episodes. 24 (1): 19–28. doi:ten.18814/epiiugs/2001/v24i1/005. Retrieved 6 Dec 2020.
  6. ^ Lucas, Sepncer (half dozen November 2018). "The GSSP Method of Chronostratigraphy: A Critical Review". Frontiers in Globe Science. half dozen: 191. Bibcode:2018FrEaS...6..191L. doi:10.3389/feart.2018.00191.
  7. ^ Holland, C. (June 1985). "Series and Stages of the Silurian Arrangement" (PDF). Episodes. 8 (2): 101–103. doi:x.18814/epiiugs/1985/v8i2/005 . Retrieved 11 December 2020.
  8. ^ Haq, B. U.; Schutter, SR (2008). "A Chronology of Paleozoic Ocean-Level Changes". Scientific discipline. 322 (5898): 64–68. Bibcode:2008Sci...322...64H. doi:10.1126/scientific discipline.1161648. PMID 18832639. S2CID 206514545.
  9. ^ "Ordovician". Dictionary.com Entire (Online). due north.d.
  10. ^ "International Chronostratigraphic Nautical chart v.2015/01" (PDF). International Commission on Stratigraphy. January 2015.
  11. ^ Charles Lapworth (1879) "On the Tripartite Classification of the Lower Palaeozoic Rocks," Geological Magazine, new series, 6 : 1-xv. From pp. 13-xiv: "North Wales itself — at all events the whole of the slap-up Bala district where Sedgwick first worked out the physical succession among the rocks of the intermediate or so-called Upper Cambrian or Lower Silurian system; and in all probability, much of the Shelve and the Caradoc area, whence Murchison first published its distinctive fossils — lay within the territory of the Ordovices; … Hither, then, have nosotros the hint for the appropriate title for the central system of the Lower Paleozoic. It should be called the Ordovician Organisation, after this quondam British tribe."
  12. ^ "New type of meteorite linked to aboriginal asteroid collision". Scientific discipline Daily. 15 June 2016. Retrieved twenty June 2016.
  13. ^ Details on the Dapingian are available at Wang, X.; Stouge, S.; Chen, 10.; Li, Z.; Wang, C. (2009). "Dapingian Stage: standard name for the lowermost global stage of the Center Ordovician Series". Lethaia. 42 (3): 377–380. doi:10.1111/j.1502-3931.2009.00169.ten.
  14. ^ "The Ordovician Period". Subcommission on Ordovician Stratigraphy. International Commission on Stratigraphy. 2020. Retrieved 7 June 2021.
  15. ^ Ogg; Ogg; Gradstein, eds. (2008). The Concise Geological Timescale.
  16. ^ Torsvik, Trond H.; Cocks, L. Robin Grand. (2017). World history and palaeogeography. Cambridge, United kingdom: Cambridge Academy Printing. p. 102. ISBN9781107105324.
  17. ^ a b c d e f g Torsvik & Cocks 2017, p. 102.
  18. ^ Pollock, Jeffrey C.; Hibbard, James P.; Sylvester, Paul J. (May 2009). "Early Ordovician rifting of Avalonia and nascence of the Rheic Body of water: U–Lead detrital zircon constraints from Newfoundland". Journal of the Geological Society. 166 (3): 501–515. Bibcode:2009JGSoc.166..501P. doi:10.1144/0016-76492008-088. S2CID 129091590.
  19. ^ Nance, R. Damian; Gutiérrez-Alonso, Gabriel; Keppie, J. Duncan; Linnemann, Ulf; Murphy, J. Brendan; Quesada, Cecilio; Strachan, Rob A.; Woodcock, Nigel H. (March 2012). "A brief history of the Rheic Ocean". Geoscience Frontiers. three (2): 125–135. doi:x.1016/j.gsf.2011.xi.008.
  20. ^ Torsvik & Cocks 2017, p. 103.
  21. ^ a b c d Torsvik & Cocks 2017, p. 112.
  22. ^ Torsvik, Trond H.; Rehnström, Emma F. (March 2001). "Cambrian palaeomagnetic information from Baltica: implications for true polar wander and Cambrian palaeogeography". Periodical of the Geological Lodge. 158 (2): 321–329. Bibcode:2001JGSoc.158..321T. doi:10.1144/jgs.158.2.321. S2CID 54656066.
  23. ^ Torsvik & Cocks 2017, pp. 102, 106.
  24. ^ van Staal, C.R.; Hatcher, R.D., Jr. (2010). "Global setting of Ordovician orogenesis". Geol Soc Am Spec Pap. 466: 1–eleven. doi:10.1130/2010.2466(01). ISBN9780813724669.
  25. ^ Torsvik & Cocks 2017, pp. 93–94.
  26. ^ Torsvik & Cocks 2017, pp. 106–109.
  27. ^ Huff, Warren D.; Bergström, Stig M.; Kolata, Dennis R. (1992-10-01). "Gigantic Ordovician volcanic ash autumn in North America and Europe: Biological, tectonomagmatic, and outcome-stratigraphic significance". Geology. 20 (10): 875–878. Bibcode:1992Geo....20..875H. doi:ten.1130/0091-7613(1992)020<0875:GOVAFI>2.three.CO;2.
  28. ^ Glen, R. A.; Meffre, S.; Scott, R. J. (March 2007). "Benambran Orogeny in the Eastern Lachlan Orogen, Australia". Australian Journal of Earth Sciences. 54 (2–3): 385–415. Bibcode:2007AuJES..54..385G. doi:10.1080/08120090601147019. S2CID 129843558.
  29. ^ Torsvik & Cocks 2017, p. 105.
  30. ^ Ramos, Victor A. (2018). "The Famatinian Orogen Along the Protomargin of Western Gondwana: Bear witness for a Nearly Continuous Ordovician Magmatic Arc Betwixt Venezuela and Argentine republic". The Evolution of the Chilean-Argentinean Andes. Springer World System Sciences: 133–161. doi:10.1007/978-3-319-67774-3_6. ISBN978-3-319-67773-6.
  31. ^ Torsvik & Cocks 2017, pp. 103–105.
  32. ^ Lindskog, A.; Costa, 1000. M.; Rasmussen, C.G.Ø.; Connelly, J. N.; Eriksson, Grand. E. (2017-01-24). "Refined Ordovician timescale reveals no link between asteroid breakdown and biodiversification". Nature Communications. 8: 14066. Bibcode:2017NatCo...814066L. doi:10.1038/ncomms14066. ISSN 2041-1723. PMC5286199. PMID 28117834.
  33. ^ Heck, Philipp R.; Schmitz, Birger; Baur, Heinrich; Halliday, Alex Northward.; Wieler, Rainer (2004). "Fast delivery of meteorites to Earth afterwards a major asteroid collision". Nature. 430 (6997): 323–five. Bibcode:2004Natur.430..323H. doi:10.1038/nature02736. PMID 15254530. S2CID 4393398.
  34. ^ Haack, Henning; Farinella, Paolo; Scott, Edward R. D.; Keil, Klaus (1996). "Meteoritic, Asteroidal, and Theoretical Constraints on the 500 MA Disruption of the L Chondrite Parent Body". Icarus. 119 (1): 182–91. Bibcode:1996Icar..119..182H. doi:ten.1006/icar.1996.0010.
  35. ^ Korochantseva, Ekaterina V.; Trieloff, Mario; Lorenz, Cyrill A.; Buykin, Alexey I.; Ivanova, Marina A.; Schwarz, Winfried H.; Hopp, Jens; Jessberger, Elmar Thou. (2007). "Fifty-chondrite asteroid breakup tied to Ordovician meteorite shower by multiple isochron 40Ar-39Ar dating". Meteoritics & Planetary Science. 42 (1): 113–30. Bibcode:2007M&PS...42..113K. doi:x.1111/j.1945-5100.2007.tb00221.10. S2CID 54513002.
  36. ^ Stanley, S.; Hardie, L. (1998). "Secular oscillations in the carbonate mineralogy of reef-building and sediment-producing organisms driven by tectonically forced shifts in seawater chemistry". Palaeogeography, Palaeoclimatology, Palaeoecology. 144 (1–2): iii–xix. Bibcode:1998PPP...144....3S. doi:ten.1016/S0031-0182(98)00109-6.
  37. ^ a b c Stanley, South. Grand.; Hardie, 50. A. (1999). "Hypercalcification; paleontology links plate tectonics and geochemistry to sedimentology". GSA Today. 9: 1–7.
  38. ^ a b c d east f 1000 h Munnecke, A.; Calner, G.; Harper, D. A. T.; Servais, T. (2010). "Ordovician and Silurian body of water-water chemistry, sea level, and climate: A synopsis". Palaeogeography, Palaeoclimatology, Palaeoecology. 296 (3–4): 389–413. Bibcode:2010PPP...296..389M. doi:ten.1016/j.palaeo.2010.08.001.
  39. ^ Trotter, J. A.; Williams, I. S.; Barnes, C. R.; Lecuyer, C.; Nicoll, R. South. (2008-07-25). "Did Cooling Oceans Trigger Ordovician Biodiversification? Bear witness from Conodont Thermometry". Scientific discipline. 321 (5888): 550–554. Bibcode:2008Sci...321..550T. doi:10.1126/science.1155814. ISSN 0036-8075. PMID 18653889. S2CID 28224399.
  40. ^ Goldberg, Samuel L.; Nowadays, Theodore M.; Finnegan, Seth; Bergmann, Kristin D. (2021-02-09). "A high-resolution record of early on Paleozoic climate". Proceedings of the National Academy of Sciences. 118 (6): e2013083118. Bibcode:2021PNAS..11820130G. doi:10.1073/pnas.2013083118. ISSN 0027-8424. PMC8017688. PMID 33526667.
  41. ^ Rasmussen, Christian K. Ø.; Ullmann, Clemens V.; Jakobsen, Kristian G.; Lindskog, Anders; Hansen, Jesper; Hansen, Thomas; Eriksson, Mats E.; Dronov, Andrei; Frei, Robert; Korte, Christoph; Nielsen, Arne T.; Harper, David A.T. (May 2016). "Onset of main Phanerozoic marine radiation sparked by emerging Mid Ordovician icehouse". Scientific Reports. 6 (1): 18884. Bibcode:2016NatSR...618884R. doi:x.1038/srep18884. PMC4702064. PMID 26733399.
  42. ^ Fortey, Richard A.; Cocks, 50. Robin G. (2005). "Late Ordovician global warming—The Boda result". Geology. 33 (5): 405. Bibcode:2005Geo....33..405F. doi:10.1130/G21180.1.
  43. ^ "Humble moss helped to absurd Earth and spurred on life".
  44. ^ Dixon, Dougal; et al. (2001). Atlas of Life on Earth. New York: Barnes & Noble Books. p. 87. ISBN978-0-7607-1957-2.
  45. ^ Palaeos Paleozoic : Ordovician : The Ordovician Menstruation Archived 2007-12-21 at the Wayback Machine
  46. ^ a b Cooper, John D.; Miller, Richard H.; Patterson, Jacqueline (1986). A Trip Through Time: Principles of Historical Geology. Columbus: Merrill Publishing Company. pp. 247, 255–259. ISBN978-0-675-20140-7.
  47. ^ a b Torsvik & Cocks 2017, p. 112-113.
  48. ^ Kröger, Björn; Yun-Bai, Zhang (March 2009). "Pulsed cephalopod diversification during the Ordovician". Palaeogeography, Palaeoclimatology, Palaeoecology. 273 (ane–2): 174–183. Bibcode:2009PPP...273..174K. doi:10.1016/j.palaeo.2008.12.015.
  49. ^ Finney, Stanley C.; Bergström, Stig M. (1986). "Biostratigraphy of the Ordovician Nemagraptus gracilis Zone". Geological Gild, London, Special Publications. 20 (1): 47–59. Bibcode:1986GSLSP..xx...47F. doi:10.1144/GSL.SP.1986.020.01.06. S2CID 129733589.
  50. ^ a b Wilson, M. A.; Palmer, T. J. (2006). "Patterns and processes in the Ordovician Bioerosion Revolution" (PDF). Ichnos. 13 (3): 109–112. doi:10.1080/10420940600850505. S2CID 128831144. Archived from the original (PDF) on 2008-12-16.
  51. ^ Vinn, O.; Mõtus, M.-A. (2012). "Diverse early endobiotic coral symbiont assemblage from the Katian (Belatedly Ordovician) of Baltica". Palaeogeography, Palaeoclimatology, Palaeoecology. 321–322: 137–141. Bibcode:2012PPP...321..137V. doi:10.1016/j.palaeo.2012.01.028. Retrieved 2014-06-eleven .
  52. ^ Vinn, O., Wilson, 1000.A., Mõtus, Thousand.-A. and Toom, U. (2014). "The earliest bryozoan parasite: Middle Ordovician (Darriwilian) of Osmussaar Island, Republic of estonia". Palaeogeography, Palaeoclimatology, Palaeoecology. 414: 129–132. Bibcode:2014PPP...414..129V. doi:10.1016/j.palaeo.2014.08.021. Retrieved 2014-01-09 . {{cite journal}}: CS1 maint: multiple names: authors list (link)
  53. ^ "Palaeos Paleozoic : Ordovician : The Ordovician Flow". April eleven, 2002. Archived from the original on December 21, 2007.
  54. ^ "A Guide to the Orders of Trilobites".
  55. ^ Garwood, Russell J.; Sharma, Prashant P.; Dunlop, Jason A.; Giribet, Gonzalo (2014). "A Paleozoic Stalk Group to Mite Harvestmen Revealed through Integration of Phylogenetics and Evolution". Current Biology. 24 (9): 1017–1023. doi:10.1016/j.cub.2014.03.039. PMID 24726154.
  56. ^ Bergström, Stig G.; Bergström, Jan; Kumpulainen, Risto; Ormö, Jens; Sturkell, Erik (2007). "Maurits Lindström – A renaissance geoscientist". GFF. 129 (2): 65–lxx. doi:10.1080/11035890701292065. S2CID 140593975.
  57. ^ Wilson, M. A.; Palmer, T. J. (2001). "Domiciles, not predatory borings: a simpler caption of the holes in Ordovician shells analyzed past Kaplan and Baumiller, 2000". PALAIOS. 16 (v): 524–525. Bibcode:2001Palai..sixteen..524W. doi:10.1669/0883-1351(2001)016<0524:DNPBAS>ii.0.CO;2.
  58. ^ a b Porada, P.; Lenton, T. G.; Pohl, A.; Weber, B.; Mander, L.; Donnadieu, Y.; Beer, C.; Pöschl, U.; Kleidon, A. (November 2016). "High potential for weathering and climate furnishings of non-vascular vegetation in the Belatedly Ordovician". Nature Communications. 7 (i): 12113. Bibcode:2016NatCo...712113P. doi:10.1038/ncomms12113. PMC4941054. PMID 27385026.
  59. ^ Steemans, P.; Herisse, A. L.; Melvin, J.; Miller, M. A.; Paris, F.; Verniers, J.; Wellman, C. H. (2009-04-17). "Origin and Radiation of the Earliest Vascular State Plants". Scientific discipline. 324 (5925): 353. Bibcode:2009Sci...324..353S. doi:10.1126/science.1169659. hdl:1854/LU-697223. PMID 19372423. S2CID 206518080.
  60. ^ Redecker, D.; Kodner, R.; Graham, L. E. (2000). "Glomalean fungi from the Ordovician". Science. 289 (5486): 1920–1921. Bibcode:2000Sci...289.1920R. doi:10.1126/science.289.5486.1920. PMID 10988069. S2CID 43553633.
  61. ^ Stanley, Steven Yard. (1999). Earth Organization History. New York: W.H. Freeman and Company. pp. 358, 360. ISBN978-0-7167-2882-5.
  62. ^ Immature, Seth A.; Saltzman, Matthew R.; Ausich, William I.; Desrochers, André; Kaljo, Dimitri (2010). "Did changes in atmospheric CO2 coincide with latest Ordovician glacial–interglacial cycles?". Palaeogeography, Palaeoclimatology, Palaeoecology. 296 (3–4): 376–388. Bibcode:2010PPP...296..376Y. doi:10.1016/j.palaeo.2010.02.033.
  63. ^ a b Jeff Hecht, High-carbon water ice age mystery solved, New Scientist, 8 March 2010 (retrieved 30 June 2014)
  64. ^ Emiliani, Cesare. (1992). Planet Earth : Cosmology, Geology, & the Evolution of Life & the Environment (Cambridge University Printing) p. 491
  65. ^ Torsvik & Cocks 2017, pp. 122–123.
  66. ^ Melott, Adrian; et al. (2004). "Did a gamma-ray flare-up initiate the late Ordovician mass extinction?". International Journal of Astrobiology. 3 (i): 55–61. arXiv:astro-ph/0309415. Bibcode:2004IJAsB...3...55M. doi:ten.1017/S1473550404001910. hdl:1808/9204. S2CID 13124815.
  67. ^ Holland, Steven M; Patzkowsky, Mark E (2015). "The stratigraphy of mass extinction". Palaeontology. 58 (v): 903–924. doi:10.1111/pala.12188. S2CID 129522636.

External links [edit]

  • Ogg, Jim (June 2004). "Overview of Global Purlieus Stratotype Sections and Points (GSSP's)". Archived from the original on 2006-04-23. Retrieved 2006-04-30 .
  • Mehrtens, Charlotte. "Chazy Reef at Island La Motte". An Ordovician reef in Vermont.
  • Ordovician fossils of the famous Cincinnatian Group
  • Ordovician (chronostratigraphy scale)

What Was The Chemical Makeup Of The Atmosphere In The Ordovician Period,

Source: https://en.wikipedia.org/wiki/Ordovician

Posted by: fifedene1987.blogspot.com

0 Response to "What Was The Chemical Makeup Of The Atmosphere In The Ordovician Period"

Post a Comment

Subscribe to: Post Comments (Atom)

Iklan Atas Artikel

Iklan Tengah Artikel 1

Iklan Tengah Artikel 2

Iklan Bawah Artikel