856:
2415:
2404:
1008:). More recent research indicates a worldwide reduction in sea level of approximately 80 meters. This drop dried up and exposed the extensive shallow-water continental shelves that existed throughout the world at that time, causing the extinction of large numbers of species who depended on this shallow water environment. Those species that survived were greatly reduced in numbers. The overall result was a major reduction in the
863:
836:(ICS) originally divided the Upper Ordovician into two stages. After considerable research, however, it was determined that no single faunal zone existed that could accommodate the upper stage of this division. Therefore, in 2003, the ICS voted to add an additional stage to its official international time scale. This was named the Hirnantian after Bancroft's stage. In 2006 the
989:. When the Hirnantian Stage began, the Earth's climate was hot and sea-levels were substantially higher than today. The seas were filled with a diverse fauna. However, there is considerable evidence to indicate that many of these species were already in trouble when the Hirnantian began, and that overall biological diversity was already in sharp decline.
829:, and A. Williams, writing in the Journal of the Geological Society of London, proposed a refinement to the Hirnantian Stage. This expanded the stage to include all of the Foel-y-Ddinas Mudstones, of which the Hirnant Limestone is a part. This expansion brought the Hirnantian Stage to its current scope.
1019:
Just as the species were adapting, however, the climate changed again. During the latter part of the
Hirnantian, temperatures rose, the glaciers melted, and sea level rose to the same or perhaps an even higher level than before the glaciation. The exposed shelves were flooded, resulting in additional
1230:
The
Hirnantian now represents an internationally accepted stage with a carefully specified global beginning and ending. However, it started out in the nineteenth century as a regional stage in the United Kingdom, where it remains as such today. Since various regions of the world have their own local
1151:
by scientists) lay to the north and west of
Gondwana, with relatively warmer climates. Rotated almost 45 degrees from their modern orientation, the eastern states of today's U.S. were located along the southeast coast of the continent, while the coastal areas of what are now the southeastern states
796:
was larger. Unlike many smaller extinction events, however, the long-term consequences of the End
Ordovician event were relatively small. Following the climatic oscillation, the climate returned to its previous state, and the species that survived soon (within two or three million years) evolved
1117:. What is now west Africa was then located at the pole, while South America was close by, joined to Africa along the latter's west coast. Along Africa's east coast were Antarctica and India, while Australia lay just to the north of them, straddling the equator. To the north of Australia was
1015:
During this ice-house period (as scientists sometimes call periods of global cold climate and glaciation), surviving species began to adapt. Cold environment species replaced the warm environment species that had thrived during the previous hot period (hot-house to scientists).
1321:
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 40 Ar- 39 Ar dating".
824:
and related sedimentary formations. These formations were located at the very top of
Ordovician deposits, and were dominated by a fauna which included brachiopods, trilobites, and other "shelly" or hard-coated animals. In 1966, D. A. Bassett,
1050:
The younger date is from the early
Silurian Birkhill shale formations. Radiometric dating placed zircon samples found in another ash deposit at 438.7 mya, with a margin of error of plus or minus 2.1 million years.
1251:
United
Kingdom β The Hirnantian is nearly equal to the regional Hirnantian stage, which starts slightly (maybe 100,000 years) earlier. The regional Hirnantian constitutes roughly the upper 20% of the Ashgill
1405:
It has been suggested that the Middle
Ordovician meteorite bombardment played a crucial role in the Great Ordovician Biodiversification Event, but this study shows that the two phenomena were unrelated
1066:
biozones in the
Hirnantian and these are of approximately equal length. The base (beginning) of the Hirnantian Stage is defined by the first appearance in the geologic record of the graptolite
1276:
992:
As the climate cooled and glaciers formed during the early part of the Hirnantian, sea level dropped. Estimates of the depth of this drop range from more than 50 meters (based on studies in
1070:, and thus, the Normalograptus extraordinarius biozone defines the early (or lower) part of the Hirnantian. The later (or upper) part is defined by the first appearance of the graptolite
1054:
With these dates as a base, scientists were able to use biostratigraphic correlation techniques to determine close approximations for the timing of various events during the Hirnantian.
962:
606:
1235:
below the Period level, the following list provides correlations between those regional stages (or epochs in some cases) and the internationally recognized Hirnantian Stage.
1435:
Chen, Xu; Rong, Jiayu; Fan, Junxuan; Zhan, Renbin; Mitchell, Charles; Harper, David; Melchin, Michael; Peng, Ping'an; Finney, Stan; Wang, Xiaofeng (September 2006).
680:
1784:
941:
937:
1751:
841:
1594:"The Global Boundary Stratotype Section and Point (GSSP) for the base of the Hirnantian Stage (the uppermost of the Ordovician System)"
1437:"The Global Boundary Stratotype Section and Point (GSSP) for the base of the Hirnantian Stage (the uppermost of the Ordovician System)"
1741:
1777:
837:
833:
552:
502:
1706:
Brenchley, P. J., 1984. "Late Ordovician extinction and their relationship to the Gondwana glaciation", in Brenchley, P. J., ed.,
876:
1735:
855:
1665:
1636:
1689:
Sheehan, Peter, "The Late Ordovician Mass Extinction" (Annual Review of Earth and Planetary Sciences, 2001, pp. 331β364).
785:
1074:, and the Normalograptus persulptus biozone lasts from then until the end of the Hirnantian. This also marks the end of the
1770:
985:
As mentioned above, there was a major climatic oscillation during the Hirnantian, which is believed to have caused a major
1646:
2448:
777:
melted, and sea level returned to the same or to a slightly higher level than it had been prior to the glaciation.
892:
632:
1032:
dates for the Hirnantian itself, there are two such dates which bracket the Hirnantian. Both dates are from the
789:
705:
1132:
Not yet joined with what would become North America were Florida, southern Georgia, and the coastal areas of
1793:
1641:. New York, NY: Britannica Educational Pub. in association with Rosen Educational Services. p. 339.
1552:
826:
793:
541:
1593:
820:
The stage was introduced in 1933 by B.B. Bancroft. As proposed by Bancroft, the Hirnantian included the
1081:
These biozones allow for additional refinement in dating events occurring within the Hirnantian Stage.
1207:
784:
that took place during this time. In fact, the Hirnantian (also known as the End Ordovician and the
769:(million years ago). The early part of the Hirnantian was characterized by cold temperatures, major
2443:
1239:
Australasia β The Hirnantian is equal to approximately the top 20% of the regional Bolindian epoch.
1746:
2066:
2061:
485:
1756:
953:
773:, and a severe drop in sea level. In the latter part of the Hirnantian, temperatures rose, the
1359:"Refined Ordovician timescale reveals no link between asteroid breakup and biodiversification"
1357:
Lindskog, A.; Costa, M. M.; Rasmussen, C.M.Γ.; Connelly, J. N.; Eriksson, M. E. (2017-01-24).
986:
1417:
1335:
1510:
1481:
1331:
586:
1613:
1453:
1144:
wedged into a gap between Africa and South America, and located very near the South pole.
8:
2438:
2397:
1530:
1232:
1188:
1122:
1485:
1391:
1358:
1343:
1298:
1271:
1029:
1245:
China β The Hirnantian is roughly equal to the upper 25% of the regional Wufeng stage.
1242:
Baltica β The Hirnantian is equivalent to the upper 50% of the regional Porkuni stage.
1097:, which occupied extreme southern latitudes and covered the south pole. This included
944:, the former containing the base of the Hirnantian. Both formations consist mainly of
2195:
2159:
1686:(The International Union of Geological Sciences and The American Geological Society).
1642:
1436:
1396:
1378:
1303:
821:
755:
352:
311:
1248:
North America β The Hirnantian is equivalent to all of the regional Gamachian stage.
1121:. It may have been the northernmost point of land in the world, located just above
2289:
2164:
2133:
1930:
1608:
1525:
1489:
1448:
1386:
1370:
1339:
1293:
1285:
781:
344:
294:
2389:
2385:
2381:
2258:
2154:
2092:
1987:
1956:
1925:
1713:
765:. It was of short duration, lasting about 1.4 million years, from 445.2 to 443.8
330:
30:
2414:
2408:
2227:
2097:
1992:
1961:
1184:
1141:
1125:
latitude. To the north of it lay a vast, uninterrupted sea, known today as the
1090:
1005:
814:
699:
1762:
2432:
2128:
2118:
2087:
2050:
1982:
1951:
1494:
1469:
1382:
1215:
1199:
1098:
1033:
907:
894:
806:
762:
720:
707:
691:
647:
634:
576:
61:
2419:
2350:
2200:
2123:
1400:
1307:
1289:
1009:
751:
1198:
by modern scientists. This consisted of what is now the southern parts of
1020:
extinctions among the fauna that had survived the first extinction event.
2345:
2214:
2190:
2035:
1830:
1219:
1211:
1133:
1126:
1089:
During the Hirnantian, much of the world's land mass was gathered into a
388:
361:
36:
1374:
780:
Most scientists believe that this climatic oscillation caused the major
2340:
2300:
2243:
2143:
2040:
1914:
1814:
1118:
1114:
1075:
1063:
1044:
957:
921:
770:
676:
618:
460:
424:
250:
81:
46:
2403:
1730:
1576:
Correlation tables of the stages Costonian-Onnian in England and Wales
1194:
Stretching westward from its southwest tip was an island arc known as
2355:
2305:
2279:
2238:
2185:
2030:
2006:
1887:
1877:
1866:
1148:
1106:
759:
379:
286:
214:
86:
792:. Approximately 85% of marine (sea-dwelling) species died. Only the
788:) mass extinction event represents the second largest such event in
2315:
2310:
2274:
2174:
2107:
2076:
1971:
1940:
1901:
1851:
1825:
1801:
1195:
1094:
397:
278:
240:
76:
71:
56:
51:
41:
2329:
2269:
2019:
1856:
1840:
1638:
The Paleozoic era : diversification of plant and animal life
1320:
1203:
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925:
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622:
91:
66:
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1180:
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1102:
1040:
1001:
993:
695:
463:
406:
370:
1356:
1187:, this area ranged from the equator in the north to more than
1039:
The older one comes from the local Hartfell shale formations.
1578:. Blakeney, Gloucestershire: Privately printed. pp. 1β4.
1110:
1047:, with a margin of error of plus or minus 2.4 million years.
949:
945:
933:
929:
810:
766:
626:
1660:
1658:
997:
886:
797:
into species very similar to the ones that existed before.
1470:"The GSSP Method of Chronostratigraphy: A Critical Review"
1655:
1545:
1155:
To the east of Laurentia, across a long, narrow sea, was
1043:
found in an ash deposit at the site was dated to 445.7
813:. Cwm Hirnant means the "valley of the long stream" in
1269:
805:
The Hirnantian was named after Cwm Hirnant south of
114:
1225:
2430:
1692:Webby, Barry D. and Mary L. Droser, eds., 2004.
840:ratified the Wangjiawan section as the official
1792:
1736:The World during the Middle and Late Ordovician
1591:
1434:
889:) of the Hirnantian is the Wangjiawan section (
501:Subdivision of the Ordovician according to the
16:Third and last age of the Late Ordovician epoch
1778:
1694:The Great Ordovician Biodiversification Event
1628:
1272:"The microfossil record of early land plants"
1710:. pp. 291β316, (John Wiley & Sons).
1587:
1585:
1567:
842:Global Boundary Stratotype Section and Point
1424:. International Commission on Stratigraphy.
1000:) to more than 100 meters (from studies in
508:Vertical axis scale: millions of years ago.
1785:
1771:
1511:"Series and Stages of the Silurian System"
862:
1612:
1582:
1529:
1493:
1452:
1390:
1297:
1634:
1573:
834:International Commission on Stratigraphy
750:is the final internationally recognized
1757:BBC Evolution Weekend: Extinction Files
1508:
880:Map of China showing the GSSP location.
2431:
973:4 cm below the boundary, and the
498:
1766:
1467:
977:Fauna 39 cm above the boundary.
800:
1731:Middle & Late Ordovician Climate
1718:Mass extinctions and their aftermath
473:
447:
2384:= kiloannum (thousands years ago);
1324:Meteoritics & Planetary Science
885:The reference lower rock boundary (
13:
2388:= megaannum (millions years ago);
1747:GeoWhen Database - Late Ordovician
1700:
1468:Lucas, Sepncer (6 November 2018).
1344:10.1111/j.1945-5100.2007.tb00221.x
1147:The rest of North America (called
14:
2460:
2392:= gigaannum (billions years ago).
1724:
1684:International Stratigraphic Guide
1206:, and eastern coastal regions of
1084:
844:(GSSP) for the Hirnantian Stage.
2413:
2402:
1668:. Geologic Timescale Foundation.
1270:Wellman, C.H.; Gray, J. (2000).
861:
854:
34:
1635:Rafferty, John P., ed. (2010).
1614:10.18814/epiiugs/2006/v29i3/004
1555:. Geologic Timescale Foundation
1454:10.18814/epiiugs/2006/v29i3/004
1226:Correlations to regional stages
1057:
980:
1752:The Ordovician Mass Extinction
1592:Chen, Xu; et al. (2006).
1531:10.18814/epiiugs/1985/v8i2/005
1502:
1461:
1428:
1410:
1350:
1314:
1263:
1068:Normalograptus extraordinarius
963:Normalograptus extraordinarius
607:Normalograptus extraordinarius
446:
1:
1831:Pleistocene (11.7 kaβ2.58 Ma)
1256:
952:. The base is defined as the
1696:(Columbia University Press).
1553:"GSSP Table - Paleozoic Era"
1036:area in the United Kingdom.
7:
1794:Geological history of Earth
1716:and Paul B. Wignall, 1997.
1682:Salvador, Amos, ed., 1994.
1666:"GSSP for Hirnantian Stage"
936:). It is an outcrop of the
827:Harry Blackmore Whittington
794:End-Permian mass extinction
499:
209:
10:
2465:
2067:Mississippian (323β359 Ma)
2062:Pennsylvanian (299β323 Ma)
1826:Holocene (presentβ11.7 ka)
1720:(Oxford University Press).
1676:
1474:Frontiers in Earth Science
29:445.2 Β± 1.4 β 443.8 Β± 1.5
2379:
2364:
2351:Paleoarchean (3.2β3.6 Ga)
2328:
2288:
2257:
2226:
2213:
2201:Terreneuvian (521β539 Ma)
2173:
2142:
2106:
2075:
2049:
2018:
2005:
1970:
1939:
1913:
1900:
1865:
1839:
1813:
1800:
1509:Holland, C. (June 1985).
1072:Normalograptus persulptus
1028:While there are no major
1023:
736:
687:
672:Upper boundary definition
671:
663:
613:
601:Lower boundary definition
600:
592:
582:
572:
567:
559:
547:
537:
532:
524:
519:
112:
107:
26:
21:
2449:Ordovician geochronology
2346:Mesoarchean (2.8β3.2 Ga)
2191:Miaolingian (497β509 Ma)
2036:Guadalupian (260β272 Ma)
1888:Paleocene (56.0β66.0 Ma)
1878:Oligocene (23.0β33.9 Ma)
1574:Bancroft, B. B. (1933).
1495:10.3389/feart.2018.00191
675:First appearance of the
117:
2341:Neoarchean (2.5β2.8 Ga)
2306:Orosirian (1.8β2.05 Ga)
2301:Statherian (1.6β1.8 Ga)
2244:Cryogenian (635β720 Ma)
2134:Llandovery (433β444 Ma)
2041:Cisuralian (272β299 Ma)
1852:Pliocene (2.59β5.33 Ma)
1336:2007M&PS...42..113K
1012:of the world's oceans.
971:Normalograptus ojsuensi
847:
486:Ordovician meteor event
200:−445 —
190:−450 —
180:−455 —
170:−460 —
160:−465 —
150:−470 —
140:−475 —
130:−480 —
120:−485 —
2311:Rhyacian (2.05β2.3 Ga)
2280:Calymmian (1.4β1.6 Ga)
2239:Ediacaran (539β635 Ma)
2186:Furongian (485β497 Ma)
2031:Lopingian (252β260 Ma)
1857:Miocene (5.33β23.0 Ma)
1290:10.1098/rstb.2000.0612
1277:Phil. Trans. R. Soc. B
969:Secondary markers are
954:first appearance datum
924:, 42 km north of
2316:Siderian (2.3β2.5 Ga)
2275:Ectasian (1.2β1.4 Ga)
2196:Series 2 (509β521 Ma)
1883:Eocene (33.9β56.0 Ma)
1363:Nature Communications
1159:. Composed of modern
987:mass extinction event
681:Akidograptus ascensus
604:FAD of the graptolite
2356:Eoarchean (3.6β4 Ga)
2249:Tonian (720 Maβ1 Ga)
2129:Wenlock (427β433 Ma)
2119:Pridoli (419β423 Ma)
1422:www.stratigraphy.org
908:30.9841Β°N 111.4197Β°E
877:class=notpageimage|
648:30.9841Β°N 111.4197Β°E
617:Wangjiawan section,
2411: •
2400: •
2398:Geologic time scale
2160:Middle (458β470 Ma)
2124:Ludlow (423β427 Ma)
2093:Middle (383β393 Ma)
1988:Middle (237β247 Ma)
1957:Middle (164β174 Ma)
1742:The Late Ordovician
1708:Fossils and Climate
1486:2018FrEaS...6..191L
1375:10.1038/ncomms14066
942:Lungmachi Formation
920:) near the village
904: /
786:Ordovician-Silurian
737:Upper GSSP ratified
717: /
688:Upper boundary GSSP
664:Lower GSSP ratified
644: /
614:Lower boundary GSSP
593:Time span formality
2409:Geology portal
2270:Stenian (1β1.2 Ga)
2165:Early (470β485 Ma)
2098:Early (393β419 Ma)
1993:Early (247β252 Ma)
1962:Early (174β201 Ma)
1931:Early (100β145 Ma)
1926:Late (66.0β100 Ma)
1759:(very brief entry)
1418:"Chart/Time Scale"
1127:Panthalassic ocean
869:Wangjiawan section
801:Naming and history
721:55.4400Β°N 3.2700Β°W
583:Stratigraphic unit
573:Chronological unit
560:Time scale(s) used
2426:
2425:
2324:
2323:
2290:Paleoproterozoic
2209:
2208:
2155:Late (444β458 Ma)
2088:Late (359β383 Ma)
2001:
2000:
1983:Late (201β237 Ma)
1952:Late (145β164 Ma)
1896:
1895:
1817:(presentβ2.58 Ma)
1805:(presentβ66.0 Ma)
1284:(1398): 717β732.
966:in that section.
913:30.9841; 111.4197
822:Hirnant Limestone
756:Ordovician Period
744:
743:
653:30.9841; 111.4197
533:Usage information
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471:
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2420:World portal
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2259:Mesoproterozoic
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1123:30 degrees north
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782:extinction event
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2444:Late Ordovician
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2228:Neoproterozoic
2218:(539 Maβ2.5 Ga)
2217:
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2215:Proterozoic Eon
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1714:Hallam, Anthony
1703:
1701:Further reading
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2246:
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2204:
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2198:
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2171:
2170:
2168:
2167:
2162:
2157:
2151:
2149:
2140:
2139:
2137:
2136:
2131:
2126:
2121:
2115:
2113:
2104:
2103:
2101:
2100:
2095:
2090:
2084:
2082:
2073:
2072:
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2058:
2056:
2051:Carboniferous
2047:
2046:
2044:
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2033:
2027:
2025:
2013:
2003:
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1908:
1898:
1897:
1894:
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1885:
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1874:
1872:
1869:(23.0β66.0 Ma)
1863:
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1860:
1859:
1854:
1848:
1846:
1843:(2.58β23.0 Ma)
1837:
1836:
1834:
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1828:
1822:
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1808:
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1738:paleogeography
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1726:
1725:External links
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1524:(2): 101β103.
1501:
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1447:(3): 183β195.
1427:
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1313:
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1260:
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1243:
1240:
1227:
1224:
1185:Ural Mountains
1142:South Carolina
1109:, the bulk of
1091:supercontinent
1086:
1085:Paleogeography
1083:
1062:There are two
1059:
1056:
1025:
1022:
1006:United Kingdom
982:
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940:and overlying
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2250:
2247:
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2232:
2230:(539 Maβ1 Ga)
2225:
2222:
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2199:
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2184:
2183:
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2179:
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2166:
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2148:
2141:
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2112:
2105:
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2074:
2068:
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2007:Paleozoic Era
2004:
1994:
1991:
1989:
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1981:
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1960:
1958:
1955:
1953:
1950:
1949:
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1945:
1938:
1932:
1929:
1927:
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1921:
1919:
1917:(66.0β145 Ma)
1912:
1909:
1907:
1905:(66.0β252 Ma)
1899:
1889:
1886:
1884:
1881:
1879:
1876:
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1610:
1607:(3): 183β96.
1606:
1602:
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1527:
1523:
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1234:
1233:geologic time
1231:divisions of
1223:
1221:
1217:
1216:New Brunswick
1213:
1209:
1205:
1201:
1197:
1192:
1190:
1186:
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1158:
1153:
1152:faced south.
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1099:South America
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843:
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798:
795:
791:
787:
783:
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749:
739:
735:
730:
701:
697:
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670:
666:
662:
657:
628:
624:
620:
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581:
578:
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571:
566:
562:
558:
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550:
546:
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540:
536:
531:
527:
523:
518:
506:
505:, as of 2021.
504:
497:
487:
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476:
475:
465:
462:
455:
450:
449:
426:
417:
408:
399:
390:
381:
372:
363:
355:
354:
346:
338:
323:
304:
288:
281:
280:
271:
270:
243:
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232:
116:
111:
106:
93:
88:
83:
78:
73:
68:
63:
58:
53:
48:
43:
38:
32:
25:
20:
2394:
2330:Archean Eon
2292:(1.6β2.5 Ga)
2177:(485β539 Ma)
2146:(444β485 Ma)
2110:(419β444 Ma)
2079:(359β419 Ma)
2053:(299β359 Ma)
2022:(252β299 Ma)
2010:(252β539 Ma)
1974:(201β252 Ma)
1943:(145β201 Ma)
1902:Mesozoic Era
1802:Cenozoic Era
1717:
1707:
1693:
1683:
1637:
1630:
1618:. Retrieved
1604:
1600:
1575:
1569:
1557:. Retrieved
1547:
1535:. Retrieved
1521:
1517:
1504:
1477:
1473:
1463:
1444:
1440:
1430:
1421:
1412:
1404:
1366:
1362:
1352:
1327:
1323:
1316:
1281:
1275:
1265:
1229:
1208:Newfoundland
1193:
1183:west of the
1154:
1146:
1131:
1088:
1080:
1071:
1067:
1061:
1058:Subdivisions
1053:
1049:
1038:
1027:
1018:
1014:
1010:biodiversity
991:
984:
981:Major events
974:
970:
968:
961:
884:
831:
819:
804:
779:
747:
745:
679:
605:
500:
415:
351:
277:
249:
239:
213:
2366:Hadean Eon
2144:Ordovician
1915:Cretaceous
1815:Quaternary
1559:30 November
1537:11 December
1220:New England
1212:Nova Scotia
1134:Mississippi
1030:radiometric
911: /
899:111Β°25β²11β³E
724: /
651: /
639:111Β°25β²11β³E
389:Darriwilian
362:Tremadocian
2439:Hirnantian
2433:Categories
2368:(4β4.6 Ga)
2332:(2.5β4 Ga)
2261:(1β1.6 Ga)
1867:Paleogene
1620:9 December
1257:References
1191:latitude.
1119:New Guinea
1115:Antarctica
1105:, most of
1076:Ordovician
1064:Graptolite
1034:Dob's Linn
958:graptolite
922:Wangjiawan
896:30Β°59β²03β³N
771:glaciation
748:Hirnantian
709:55Β°26β²24β³N
692:Dob's Linn
677:graptolite
636:30Β°59β²03β³N
619:Wangjiawan
568:Definition
461:land plant
425:Rhuddanian
416:Hirnantian
108:Chronology
22:Hirnantian
2395:See also:
2175:Cambrian
2108:Silurian
2077:Devonian
1972:Triassic
1941:Jurassic
1383:2041-1723
1369:: 14066.
1149:Laurentia
1107:Australia
975:Hirnantia
760:Paleozoic
712:3Β°16β²12β³W
520:Etymology
380:Dapingian
2020:Permian
1841:Neogene
1601:Episodes
1518:Episodes
1441:Episodes
1401:28117834
1308:10905606
1196:Avalonia
1095:Gondwana
1078:Period.
1004:and the
960:species
775:glaciers
551:Global (
398:Sandbian
353:Stage 10
1677:Sources
1482:Bibcode
1480:: 191.
1392:5286199
1332:Bibcode
1299:1692785
1204:Ireland
1200:Britain
1177:Germany
1173:Denmark
1169:Finland
1157:Baltica
1138:Alabama
1093:called
956:of the
926:Yichang
758:of the
754:of the
623:Yichang
478:←
452:←
205:–
195:–
185:–
175:–
165:–
155:–
145:–
135:–
125:–
98:↓
2374:
1645:
1399:
1389:
1381:
1306:
1296:
1252:epoch.
1218:, and
1181:Russia
1165:Sweden
1161:Norway
1140:, and
1113:, and
1103:Africa
1041:Zircon
1024:Dating
1002:Norway
994:Nevada
938:Wufeng
696:Moffat
596:Formal
528:Formal
464:spores
459:First
442:
437:
432:
407:Katian
371:Floian
1597:(PDF)
1514:(PDF)
1111:India
950:chert
946:shale
934:China
930:Hubei
815:Welsh
811:Wales
752:stage
627:China
587:Stage
542:Earth
1643:ISBN
1622:2013
1561:2012
1539:2020
1397:PMID
1379:ISSN
1304:PMID
1202:and
1179:and
998:Utah
996:and
948:and
887:GSSP
848:GSSP
832:The
807:Bala
746:The
740:1984
700:U.K.
667:2006
37:Preκ
1609:doi
1526:doi
1490:doi
1449:doi
1387:PMC
1371:doi
1340:doi
1294:PMC
1286:doi
1282:355
1045:mya
838:ICS
763:Era
577:Age
553:ICS
503:ICS
2435::
2390:Ga
2386:Ma
2382:ka
1657:^
1605:29
1603:.
1599:.
1584:^
1520:.
1516:.
1488:.
1476:.
1472:.
1445:29
1443:.
1439:.
1420:.
1403:.
1395:.
1385:.
1377:.
1365:.
1361:.
1338:.
1328:42
1326:.
1302:.
1292:.
1280:.
1274:.
1222:.
1214:,
1210:,
1171:,
1167:,
1163:,
1136:,
1129:.
1101:,
932:,
817:.
767:Ma
698:,
694:,
625:,
621:,
231:c
229:i
227:o
225:z
223:o
221:e
219:l
217:a
215:P
87:Pg
31:Ma
1786:e
1779:t
1772:v
1651:.
1624:.
1611::
1563:.
1541:.
1528::
1522:8
1498:.
1492::
1484::
1478:6
1457:.
1451::
1373::
1367:8
1346:.
1342::
1334::
1310:.
1288::
928:(
555:)
345:L
337:e
335:t
333:a
331:L
322:e
320:l
318:d
316:d
314:i
312:M
303:y
301:l
299:r
297:a
295:E
287:F
279:S
269:n
267:a
265:i
263:c
261:i
259:v
257:o
255:d
253:r
251:O
241:κ
92:N
82:K
77:J
72:T
67:P
62:C
57:D
52:S
47:O
42:κ
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.