73:, summarized in Table 1. Due to erosion from the associated glaciation, the thickness of these sections are small, often not larger than several meters to tens to meters in thickness. Most preserved rocks are shallow water deposits, but some notable deeper water deposits exist in China. These formations mostly show a regular trend of initial deep sea rocks like shale and mudstones, then deposition of shallow limestone's during the Hirnantian. These then returned to deep shales and muds as water rose again at the end of the Hirnantian due to de-glaciation. Rocks which stayed in deep water environments during the HICE continued to deposit mudstones or shale. Most sections analyzed for carbon 13 isotope ratio’s (δ13C) show a positive shift of +3-6%, although some sections show values as high as +7% or as low as +2%.
293:(SPICE), a positive excursion of up to +5% δ13C which lasted for 2-4 million years and occurred around 295 Ma ago. Both excursions have similar proposed causes, including enhanced burial of carbon and weathering of carbonates. The two excursions are also of a similar time frame, lasting in the single digit millions of years.
277:
biozone. When some or entire sections of these fossils are missing, it can complicate reconstruction and correlation of sections. Some localities are interpreted to show the peak of the HICE at the start of the
Hirnantian, while others are interpreted to not reach their peak until later into the age.
268:
Aside from the cause and age, other parts of the HICE are also still debated. For example, some studies have shown that there may have been multiple cycles of sea level rise and fall within this time period. Disagreement also exists over the exact timing of the HICE. Biostratigraphy is often used to
796:
Brenchley, P.J; Carden, G.A; Hints, L; Kalijo, D; Marshall, J.D; Martma, T; Meidla, T; Nõlvak, J (2003). "High-resolution stable isotope stratigraphy of Upper
Ordovician sequences: Constraints on the timing of bioevents and environmental changes associated with mass extinction and glaciation".
255:
Age created more space and nutrients for marine eukaryotes, which grew larger and thus sank to the ocean floor more readily, burying more organic carbon in the sediments. The other hypothesis states that a cooling trend through the Katian created glacial conditions, and the retreating glaciers
45:
is 445.2 (±1.3) Ma to 443.8 (± 1.5). Another proposed date for the HICE is 443.14 (± 0.24) Ma to 442.67 Ma (± 0.34). Major uncertainty over the age is partly due to the short time frame of both the HICE and
Hirnantian age and comparatively large statistical error on these dates.
745:
259:
Many of the deeper water sections show lower increases in δ13C than the shallow water sections. It's been proposed that the deep water rocks represent the true signal of the HICE, while the shallow water rocks show a higher value due to alteration.
367:
Ling, Ming-Xing; Zhan, Ren-Bin; Wang, Guang-Xu; Wang, Yi; Amelin, Yuri; Tang, Peng; Liu, Jian-Bo; Jin, Jisuo; Huang, Bing; Wu, Rong-Chang; Xue, Shuo; Fu, Bin; Bennett, Vickie C.; Wei, Xin; Luan, Xiao-Cong (December 2019).
250:
The exact cause of the HICE is still debated, although there are 2 main hypotheses. One hypothesis states that it was primarily due to enhanced burial of carbon. High water levels and enhanced weathering in the earlier
40:
The HICE is widely recognized as short in terms of geologic time, but just how short is still debated. The current official timing of the
Hirnantian, and thus the HICE, in the geologic record according to the
940:
Xu, Chen; Sheets, David H; Melchin, Michael J.; Mitchell, Charles E (2005). "Patterns and
Processes of Latest Ordovician Graptolite Extinction and Recovery Based on Data from South China".
696:
Finney, Stanley C.; Berry, William B. N.; Cooper, John D.; Ripperdan, Robert L.; Sweet, Walter C.; Jacobson, Stephen R.; Soufiane, Azzedine; Achab, Aicha; Noble, Paula J. (1999-03-01).
1055:
Saltzman, Matthew R.; Ripperdan, Robert L.; Brasier, M. D.; Lohmann, Kyger C.; Robison, Richard A.; Chang, W. T.; Peng, Shanchi; Ergaliev, E. K.; Runnegar, Bruce (2000-10-01).
1163:
893:"Upper Ordovician (Hirnantian) to Lower Silurian (Telychian, Llandovery) graptolite biostratigraphy of the Tielugou section, Shennongjia anticline, Hubei Province, China"
256:
exposed large numbers of near-shore marine carbonates to weathering. The weathering of these carbonates pumped more carbon back into the ocean, raising the buried δ13C.
520:
32:, which wiped out 85% of marine life. The exact cause of the HICE is still debated, however it is a key event for defining the Ordovician-Silurian boundary.
290:
990:
Saltzman, M.R; Thomas, E (2012). "Chapter 11 - Carbon
Isotope Stratigraphy". In Gradstein, Felix.M; Ogg, James G.; Schmitz, Mark D.; Ogg, Gabi M. (eds.).
646:"Carbon isotope chemostratigraphy in Arctic Canada: Sea-level forcing of carbonate platform weathering and implications for Hirnantian global correlation"
315:
Shen, Jiaheng; Pearson, Ann; Henkes, Gregory A.; Zhang, Yi Ge; Chen, Kefan; Li, Dandan; Wankel, Scott D.; Finney, Stanley C.; Shen, Yanan (July 2018).
42:
1168:
838:
1057:"A global carbon isotope excursion (SPICE) during the Late Cambrian: relation to trilobite extinctions, organic-matter burial and sea level"
967:
Cooper, R.A; Sadler, P.M (2012). "Chapter 20: The
Ordovician Period". In Gradstein, Felix; Ogg, J.G; Schmitz, Mark D.; Ogg, Gabi M. (eds.).
744:
Calner, Mikael; Bockelie, Johan
Fredrik; Rasmussen, Christian M. Ø; Calner, Hanna; Lehnert, Oliver; Joachimski, Michael M. (November 2021).
746:"Carbon isotope chemostratigraphy and sea-level history of the Hirnantian Stage (uppermost Ordovician) in the Oslo–Asker district, Norway"
28:
Age from around 445.2 Ma to 443.8 Ma (million years ago). The HICE is connected to a large scale, but short glaciation, as well as the
1005:
Shields, Graham A.; Mills, Benjamin J. W.; Zhu, Maoyan; Raub, Timothy D.; Daines, Stuart J.; Lenton, Timothy M. (October 2019).
592:"High-Resolution carbon isotope stratigraphy of the basal Silurian Stratotype (Dob's Linn, Scotland) and its global correlation"
463:"The end-Ordovician glaciation and the Hirnantian Stage: A global review and questions about Late Ordovician event stratigraphy"
29:
521:"Terminal Ordovician carbon isotope stratigraphy and glacioeustatic sea-level change across Anticosti Island (Québec, Canada)"
414:
Zhou, Lian; Algeo, Thomas J.; Shen, Jun; Hu, ZhiFang; Gong, Hongmei; Xie, Shucheng; Huang, JunHua; Gao, Shan (2015-02-15).
278:
This, along with the small section thicknesses, can make it difficult to correlate sections worldwide with one another.
1173:
49:
Complete sections of
Hirnantian age rocks outcrop primarily across the Northern Hemisphere, with notable sections in
953:
818:
721:
1007:"Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial"
839:"Sea level, carbonate mineralogy, and early diagenesis controlled δ13C records in Upper Ordovician carbonates"
269:
aid in identifying the
Hirnantian, and thus the HICE, where the Hirnantian is defined as encompassing the
1158:
285:, but is of a comparable to lower magnitude compared to other positive carbon isotope excursions in the
1106:
1056:
645:
462:
416:"Changes in marine productivity and redox conditions during the Late Ordovician Hirnantian glaciation"
415:
1118:
1068:
1018:
972:
904:
865:
837:
Jones, David; Brothers, Roger; Ahm, Anne-Sofie; Slater, Nicholas; Higgins, John; Fike, David (2019).
806:
757:
709:
657:
603:
535:
474:
427:
381:
328:
519:
Jones, David; Fike, David; Finnegan, Seth; Fischer, Woodward; Schrag, Daniel; McCay, Dwight (2011).
698:"Late Ordovician mass extinction: A new perspective from stratigraphic sections in central Nevada"
369:
281:
The HICE is far shorter and smaller in magnitude than other isotopic excursions from the earlier
591:
1134:
1084:
1034:
922:
775:
673:
619:
490:
443:
344:
1107:"The upper Cambrian SPICE carbon isotope excursion from the Alborz Ranges, northeastern Iran"
1126:
1076:
1026:
949:
912:
873:
814:
765:
717:
665:
611:
543:
482:
435:
389:
336:
317:"Improved efficiency of the biological pump as a trigger for the Late Ordovician glaciation"
1122:
1072:
1022:
976:
908:
869:
810:
761:
713:
697:
661:
607:
539:
478:
431:
385:
370:"An extremely brief end Ordovician mass extinction linked to abrupt onset of glaciation"
332:
1080:
1152:
62:
1130:
1006:
486:
316:
669:
590:
Underwood, C. J.; Crowley, S. F.; Marshall, J. D.; Brenchley, P. J. (July 1997).
439:
20:(HICE) is a positive carbon isotope excursion which took place at the end of the
393:
286:
282:
917:
1030:
770:
340:
25:
21:
1138:
1088:
1038:
926:
892:
877:
779:
677:
623:
615:
494:
447:
348:
854:"Changes in marine isotopic composition and the late Ordovician glaciation"
853:
1105:
Navidi-Izad, Navid; Hashemi, Hossein; Saltzman, Matthew R. (2024-02-01).
54:
891:
Maletz, Jörg; Wang, Chuanshang; Kai, Wei; Wang, Xiaofeng (2021-09-01).
547:
252:
70:
66:
58:
50:
561:
954:
10.1666/0022-3360(2005)079[0842:PAPOLO]2.0.CO;2
819:
10.1130/0016-7606(2003)115<0089:HRSISO>2.0.CO;2
722:
10.1130/0091-7613(1999)027<0215:LOMEAN>2.3.CO;2
175:
West to Northern Latvia (Kuldiga and Saldus Formations)
206:
Dob's Linn (Upper Hartfell, Lower Birkhill Formations)
289:. The closest comparable excursion to the HICE is the
134:Wangjiawan (Upper Wufeng, Kuanyinchiao Formations)
644:Melchin, Michael J.; Holmden, Chris (2006-05-18).
1061:Palaeogeography, Palaeoclimatology, Palaeoecology
650:Palaeogeography, Palaeoclimatology, Palaeoecology
420:Palaeogeography, Palaeoclimatology, Palaeoecology
147:Nanbazi (Upper Wufeng, Kuanyinchiao Formations)
191:Upper Husbergøya, and Lower Solvik Formations)
8:
120:Cornwallis Island (Cape Phillips Embayment)
291:Steptoean positive carbon isotope excursion
562:"International Commission on Stratigraphy"
1164:History of climate variability and change
916:
852:Marshall, James; Middleton, Paul (1990).
769:
461:Delabroye, A.; Vecoli, M. (2010-02-01).
75:
43:International Commission on Stratigraphy
302:
233:Monitor Range (Hanson Creek Formation)
107:Anticosti Island (Ellis Bay Formation)
791:
789:
528:Geological Society of America Bulletin
1100:
1098:
1050:
1048:
832:
830:
828:
739:
737:
735:
733:
731:
691:
689:
687:
7:
639:
637:
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633:
585:
583:
581:
514:
512:
510:
508:
506:
504:
409:
407:
405:
403:
362:
360:
358:
310:
308:
306:
18:Hirnantian Isotopic Carbon Excursion
841:. 48(2). Geology. p. 194-199.
161:Central Estonia (Ärina Formation)
14:
858:Journal of the Geological Society
596:Journal of the Geological Society
220:Vinini Creek (Vinini Formation)
1131:10.1016/j.marpetgeo.2023.106635
487:10.1016/j.earscirev.2009.10.010
189:Oslofjord (Langøyene, Langara,
1169:Events that forced the climate
971:. Elsevier. pp. 489–507.
30:End Ordovician mass extinction
1:
1081:10.1016/S0031-0182(00)00128-0
994:. Elsevier. pp. 207–232.
1111:Marine and Petroleum Geology
969:The Geologic Time Scale 2012
670:10.1016/j.palaeo.2005.10.009
440:10.1016/j.palaeo.2014.12.012
394:10.1016/j.sesci.2019.11.001
1190:
918:10.1007/s12542-020-00544-5
1031:10.1038/s41561-019-0434-3
956:– via ResearchGate.
771:10.1017/S0016756821000546
341:10.1038/s41561-018-0141-5
217:United States of America
878:10.1144/gsjgs.147.1.0001
616:10.1144/gsjgs.154.4.0709
992:The Geologic Time Scale
942:Journal of Paleontology
264:Debates and comparisons
36:Timing and stratigraphy
88:Location and Formation
467:Earth-Science Reviews
374:Solid Earth Sciences
98:δ13C Range (At Peak)
1123:2024MarPG.16006635N
1073:2000PPP...162..211S
1023:2019NatGe..12..823S
977:2012gts..book.....G
909:2021PalZ...95..453M
870:1990JGSoc.147....1M
811:2003GSAB..115...89B
762:2021GeoM..158.1977C
750:Geological Magazine
714:1999Geo....27..215F
662:2006PPP...234..186M
608:1997JGSoc.154..709U
540:2011GSAB..123.1645J
479:2010ESRv...98..269D
432:2015PPP...420..223Z
386:2019SolES...4..190L
333:2018NatGe..11..510S
78:
24:period, during the
1174:Isotope excursions
534:(7/8): 1645–1664.
271:N. extraordinarius
76:
1011:Nature Geoscience
756:(11): 1977–2008.
321:Nature Geoscience
243:
242:
1181:
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1142:
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566:stratigraphy.org
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548:10.1130/B30323.1
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273:biozone and the
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1149:
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1147:
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1017:(10): 823–827.
1004:
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989:
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966:
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961:
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5:
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1177:
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1171:
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1161:
1151:
1150:
1145:
1144:
1094:
1067:(3): 211–223.
1044:
997:
982:
959:
948:(5): 842–861.
932:
903:(3): 453–481.
883:
844:
824:
785:
727:
683:
656:(2): 186–200.
629:
602:(4): 709–718.
577:
553:
500:
473:(3): 269–282.
453:
399:
380:(4): 190–198.
354:
327:(7): 510–514.
301:
300:
298:
295:
275:N. presculptus
265:
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247:
244:
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101:
100:
95:
93:HICE Thickness
90:
85:
37:
34:
13:
10:
9:
6:
4:
3:
2:
1186:
1175:
1172:
1170:
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1157:
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1140:
1136:
1132:
1128:
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1120:
1116:
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1016:
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993:
986:
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947:
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933:
928:
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919:
914:
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898:
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871:
867:
863:
859:
855:
848:
845:
840:
833:
831:
829:
825:
820:
816:
812:
808:
805:(1): 89–105.
804:
800:
792:
790:
786:
781:
777:
772:
767:
763:
759:
755:
751:
747:
740:
738:
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728:
723:
719:
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63:United States
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56:
52:
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35:
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31:
27:
23:
19:
1159:Stratigraphy
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1110:
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991:
985:
968:
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802:
799:GSA Bulletin
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569:. Retrieved
565:
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97:
92:
87:
82:
48:
39:
17:
15:
426:: 223–234.
287:Phanerozoic
283:Precambrian
1153:Categories
1117:: 106635.
864:(1): 1–4.
708:(3): 215.
571:2024-02-26
297:References
26:Hirnantian
22:Ordovician
1139:0264-8172
1089:0031-0182
1039:1752-0908
927:1867-6812
780:0016-7568
678:0031-0182
624:0016-7649
495:0012-8252
448:0031-0182
349:1752-0908
203:Scotland
77:Table 1:
158:Estonia
55:Scotland
1119:Bibcode
1069:Bibcode
1019:Bibcode
973:Bibcode
905:Bibcode
866:Bibcode
807:Bibcode
758:Bibcode
710:Bibcode
702:Geology
658:Bibcode
604:Bibcode
536:Bibcode
475:Bibcode
428:Bibcode
382:Bibcode
329:Bibcode
195:13-51m
186:Norway
178:14-21m
172:Latvia
123:10-15m
104:Canada
83:Country
1137:
1087:
1037:
925:
778:
676:
622:
493:
446:
347:
253:Katian
246:Causes
209:~3.5m
131:China
110:~7.5m
71:Latvia
69:, and
67:Norway
61:, the
59:Canada
524:(PDF)
239:4-6%
236:~40m
226:2-3%
198:3-6%
181:3-6%
167:2-6%
164:3-6m
153:3-4%
140:2-3%
137:1.2m
126:3-6%
113:3-4%
51:China
1135:ISSN
1085:ISSN
1035:ISSN
923:ISSN
897:PalZ
776:ISSN
674:ISSN
620:ISSN
491:ISSN
444:ISSN
345:ISSN
223:10m
150:~7m
16:The
1127:doi
1115:160
1077:doi
1065:162
1027:doi
950:doi
913:doi
874:doi
862:147
815:doi
803:115
766:doi
754:158
718:doi
666:doi
654:234
612:doi
600:154
544:doi
532:123
483:doi
436:doi
424:420
390:doi
337:doi
212:3%
1155::
1133:.
1125:.
1113:.
1109:.
1097:^
1083:.
1075:.
1063:.
1059:.
1047:^
1033:.
1025:.
1015:12
1013:.
1009:.
946:79
944:.
921:.
911:.
901:95
899:.
895:.
872:.
860:.
856:.
827:^
813:.
801:.
788:^
774:.
764:.
752:.
748:.
730:^
716:.
706:27
704:.
700:.
686:^
672:.
664:.
652:.
648:.
632:^
618:.
610:.
598:.
594:.
580:^
564:.
542:.
530:.
526:.
503:^
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