Stenian

Stenian
Stenian
	A map of Proto-Rodinia on 1040 mya showing a possible reconstruction of the time.
Chronology
←	First appearance of Bangiomorpha pubescens
←	Large-scale mountain-building from continent-continent collision of the Grenvillian orogeny
←	Development of the North American Midcontinent Rift
	Events of the Stenian Period; Vertical axis scale: Millions of years ago
Etymology
Name formality	Formal
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Period
Stratigraphic unit	System
Time span formality	Formal
Lower boundary definition	Defined chronometrically
Lower GSSA ratified	1990
Upper boundary definition	Defined chronometrically
Upper GSSA ratified	1990

The Stenian Period (/ˈstiːni.ən/ STEE-nee-ən, from Ancient Greek: στενός, romanized: stenós, meaning "narrow") is the final geologic period in the Mesoproterozoic Era and lasted from 1200 Mya to 1000 Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically due to the scarcity of Precambrian fossils and lack of reliable zonation. It is preceded by the Ectasian Period and followed by the Neoproterozoic era and the Tonian period.

The supercontinent Rodinia finished assembly during the Stenian, having started during the Ectasian. It would last into the Tonian period before breaking up in the Cryogenian. Rodinia was surrounded by the Mirovian ocean during this time. This closed many seas that formed from the breakup of Columbia.^[5]

History

Before the Stenian was defined as a period in 1991, the Riphean age was defined from 1600 to 600 Mya, primarily used in Russia and textbooks across the world.^[6] The Stenian period was created in 1991 by K.A. Plumb as part of the New Precambrian time scale, defined as 1200 to 1000 Mya.^[7] The name Stenian comes from Ancient Greek: στενός, romanized: stenós, meaning narrow and referring to the narrow polymetamorphic belts in this period.^[8]

Geography

Most reconstructions of Rodinia have Laurentia placed in the center of Rodinia, being surrounded by other cratons.^[9] Laurentia itself was surrounded in the majority of interpretations by the East European Craton in the southeast, Amazonia in the south, the Río de la Plata Craton and possible the Kalahari Craton and Congo Craton in the southeast, India and possibly East Antarctic Shield in the northeast, and the Australian cratons in the north. Siberia, North, and South China cratons vary significantly in position depending on the reconstruction.^[10]^[11]^[12] Rodinia itself was surrounded by the superocean Mirovia.^[5]

Geology

This period includes the formation of the Keweenawan Rift at about 1100 Mya which led to the Keweenawan Supergroup, being the largest failed rift in Earth's history.^[13]^[14] The Musgrave orogeny also happened around this period from 1.22 to 1.12 billion years ago forming the Musgrave Block, with the Warakurna Large igneous province forming at 1076 ± 6 million years ago.^[15]

From 1.7 Gya to 1.1 Gya, there is a lack of paleosols. This also happens from the end of the period onward to 0.7 Gya.^[16] The seafloor was primarily non-oxic, with 25% oxic and recurring euxinic episodes.^[17]

Orogenies

The Grenville orogeny mainly took place in this period spanning from 1250 to 980 Mya, with the Elzerian orogeny ending in this period, the Shawingian and Ottawan orogenies taking place entirely in the Stenian, and the Rigolet orogeny starting at 1010 Mya.^[8]

Outside of North America and Australia, the Kibaran orogeny, the Dalslandian orogeny, and the Sunsás orogeny also took effect around this time. All of these orogenies helped form and stabilize the supercontinent Rodinia.^[18]^[19]^[20]

The Torridonian supergroup was primarily formed along Scotland in this period onwards, being constrained to at most 1100 Mya.^[21]^[22] The Nonesuch Shale was also formed around 1.1 Gya and spans from Michigan to Iowa.^[23]

Biology

*Bangiomorpha pubescens*, the first known sexually reproducing organism.

Fossils of the oldest known sexually reproducing organism, Bangiomorpha pubescens, first appeared in the Stenian at the Hunting Formation in Somerset Island around 1.047 Bya.^[24]^[1]^[15]^[25] The first known preserved case of multicellularity in green algae also originates from this period, specifically Proterocladus antiquus known from roughly 1 billion years ago.^[26]

Acritarchs became more abundant and spiny around this time, suggesting an increased rate in eukaryvory which forced an evolutionary response.^[15]

Stromatolites peaked in diversity in this period and swiftly declined in numbers at the end of the period around 1 billion years ago.^[27]^[28] Eukaryotes seem to have dominated non-marine habitats by 1 Ga.^[29]

Climate

The Sun produced 5-18% less output during the Proterozoic, with the Stenian's output being in the middle of the range.^[30] The CO₂ levels were no more than 10x pre-industrial levels during this time, with a reasonable methogenic flux of 10-20x current levels.^[30] The oxygen level during the Stenian was still low compared to today, being around 0.5% to 5% present atmospheric levels.^[17]^[31] There were no major glaciation events and the length of day was approximately 18.94 ± 0.39 h.^[32]

Citations

^ ^a ^b Gibson, Timothy M.; Shih, Patrick M.; Cumming, Vivien M.; Fischer, Woodward W.; Crockford, Peter W.; Hodgskiss, Malcolm S.W.; Wörndle, Sarah; Creaser, Robert A.; Rainbird, Robert H.; Skulski, Thomas M.; Halverson, Galen P. (February 2018). "Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis". Geology. 46 (2): 135–138. doi:10.1130/G39829.1. eISSN 1943-2682. ISSN 0091-7613.
^ McLelland, James M.; Selleck, Bruce W.; Bickford, M. E. (2010). "Review of the Proterozoic evolution of the Grenville Province, its Adirondack outlier, and the Mesoproterozoic inliers of the Appalachians". In Tollo, Richard P.; Bartholomew, Mervin J.; Hibbard, James P.; Karabinos, Paul M. (eds.). From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region. doi:10.1130/2010.1206(02). ISBN 978-0-8137-1206-2. LCCN 2010003691.
^ Swanson-Hysell, Nicholas L.; Ramezani, Jahandar; Fairchild, Luke M.; Rose, Ian R. (May 2019). "Failed rifting and fast drifting: Midcontinent Rift development, Laurentia's rapid motion and the driver of Grenvillian orogenesis". GSA Bulletin. 131 (5–6): 913–940. doi:10.1130/B31944.1. eISSN 1943-2674. ISSN 0016-7606.
^ ^a ^b Plumb, Kenneth A. (June 1991). "New Precambrian time scale". Episodes. 14 (2): 139–140. doi:10.18814/epiiugs/1991/v14i2/005. eISSN 2586-1298. ISSN 0705-3797. LCCN 78646808. OCLC 4130038. S2CID 126954461.
^ ^a ^b Martin, E. L.; Spencer, C. J.; Collins, W. J.; Thomas, R. J.; Macey, P. H.; Roberts, N. M. W. (2020-12-01). "The core of Rodinia formed by the juxtaposition of opposed retreating and advancing accretionary orogens". Earth-Science Reviews. 211 103413. doi:10.1016/j.earscirev.2020.103413. ISSN 0012-8252.
^ Paulamäki, Seppo; Kuivamäki, Aimo (May 2006). "Depositional History and Tectonic Regimeswithin and in the Margins of the Fennoscandian Shield During the last 1300 Million years" (PDF). Archived from the original (PDF) on 2018-02-27. Retrieved 2026-03-24.
^ Plumb, K. A. (1991-06-01). "New Precambrian time scale". Episodes Journal of International Geoscience. 14 (2): 139–140. doi:10.18814/epiiugs/1991/v14i2/005.
^ ^a ^b Tollo, Richard P. (2004-01-01). Proterozoic Tectonic Evolution of the Grenville Orogen in North America. Geological Society of America. ISBN 978-0-8137-1197-3.
^ Li, Z.X.; Bogdanova, Svetlana V. (January 2008). "Assembly, configuration, and break-up history of Rodinia: A synthesis". ResearchGate. Retrieved March 26, 2026.
^ For a comparison of the SWEAT, AUSWUS, AUSMEX, and Missing-link reconstructions see Li et al. 2008, Fig. 2, p. 182. For a comparison between the "consensus" Rodinia of Li et al. 2008 and the original proposal of McMenamin & McMenamin 1990 see Nance, Murphy & Santosh 2014, Fig. 11, p. 9.
^ Examples of reconstructions can be found in Stanley 1999, pp. 336–337; Weil et al. 1998, Fig. 6, p. 21; Torsvik 2003, Fig. 'Rodinia old and new', p. 1380; Dalziel 1997, Fig. 11, p. 31; Scotese 2009, Fig. 1, p. 69
^ Wang, Chong; Peng, Peng; Wang, Xinping; Yang, Shuyan (October 2016). "Nature of three Proterozoic (1680 Ma, 1230 Ma and 775 Ma) mafic dyke swarms in North China: Implications for tectonic evolution and paleogeographic reconstruction". Precambrian Research. 285: 109–126. Bibcode:2016PreR..285..109W. doi:10.1016/j.precamres.2016.09.015. Retrieved 17 December 2022.
^ Reeves, T.K.; Carroll, Herbert B. (April 1999). "Geologic Analysis of Priority Basins for Exploration and Drilling". Retrieved March 25, 2026.
^ "Organic geochemical study of mineralization in the Keweenawan Nonesuch Formation at White Pine, Michigan" (PDF). University of Michigan. Retrieved 28 September 2011.
^ ^a ^b ^c R., Manjunath (July 3, 2021). Timelines of Nearly Everything. India: Manjunath.R. p. 167.
^ Planavsky, Noah J.; Tarhan, Lidya G.; Bellefroid, Eric J.; Evans, David A.D.; Reinhard, Christopher T.; Love, Gordon D.; Lyons, Timothy W. (1 May 2016). "LATE PROTEROZOIC TRANSITIONS IN CLIMATE, OXYGEN, AND TECTONICS, AND THE RISE OF COMPLEX LIFE" (PDF). Retrieved 24 March 2026.
^ ^a ^b Yan, Hao; Qin, Zheng; Xu, Lingang; Mao, Jingwen; Tang, Dongjie; Huang, Qin; Yang, Xiuqing; Li, Zhiquan; Li, Jie; Li, Long; Robbins, Leslie J.; Kendall, Brian; Canfield, Donald E.; Konhauser, Kurt O. (2025-11-26). "An expansive global oxygenation of Earth's surface environments 1.4 billion years ago". Nature Communications. 16 (1): 10535. doi:10.1038/s41467-025-65551-z. ISSN 2041-1723.
^ Tack, L.; Wingate, M. T. D.; De Waele, B.; Meert, J.; Belousova, E.; Griffin, B.; Tahon, A.; Fernandez-Alonso, M. (2010-06-01). "The 1375 Ma "Kibaran event" in Central Africa: Prominent emplacement of bimodal magmatism under extensional regime". Precambrian Research. 180 (1): 63–84. doi:10.1016/j.precamres.2010.02.022. ISSN 0301-9268.
^ Santos, J. O. S.; Rizzotto, G. J.; Potter, P. E.; McNaughton, N. J.; Matos, R. S.; Hartmann, L. A.; Chemale, F.; Quadros, M. E. S. (2008-09-20). "Age and autochthonous evolution of the Sunsás Orogen in West Amazon Craton based on mapping and U–Pb geochronology". Precambrian Research. 165 (3): 120–152. doi:10.1016/j.precamres.2008.06.009. ISSN 0301-9268.
^ Slagstad, Trond; Roberts, Nick M. W.; Marker, Mogens; Røhr, Torkil S.; Schiellerup, Henrik (2012-09-03). "A non‐collisional, accretionary Sveconorwegian orogen". Terra Nova. 25 (1): 30–37. doi:10.1111/ter.12001. ISSN 0954-4879. Archived from the original on 2023-08-02.
^ Trewin, N. H. (2003-02-24). The Geology of Scotland, 4th edition. Geological Society of London. ISBN 978-1-86239-126-0.
^ "Lyell Collection". Lyell Collection. Retrieved 2026-03-24.
^ Albert B Dickas, "Midcontinent rift system: Precambrian hydrocarbon target," Oil and Gas Journal, 15 October 1984, p.151-159.
^ Butterfield, Nicholas J. (2000). "Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes". Cambridge University Press. 26 (3): 386–404. doi:10.1666/0094-8373(2000)026<0386:BPNGNS>2.0.CO;2.
^ Gibson, Timothy (February 2018). "Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis". ResearchGate. Retrieved Mar 3, 2026.
^ Tang, Qing; Pang, Ke; Yuan, Xunlai; Xiao, Shuhai (2020-02-24). "A one-billion-year-old multicellular chlorophyte". Nature Ecology & Evolution. 4 (4): 543–549. doi:10.1038/s41559-020-1122-9. ISSN 2397-334X. PMC 8668152. PMID 32094536.
^ Winner, Cherie (November 15, 2013). "What Doomed the Stromatolites?". Woods Hole Oceanographic Institution. Retrieved 2026-03-24.
^ McGuinness, Marian (2021-01-18). "Stromatolites: The Earth's oldest living lifeforms". BBC. Retrieved 2026-03-24.
^ Strother, Paul K.; Battison, Leila; Brasier, Martin D.; Wellman, Charles H. (May 2011). "Earth's earliest non-marine eukaryotes". Nature. 473 (7348): 505–509. doi:10.1038/nature09943. ISSN 1476-4687.
^ ^a ^b Sheldon, Nathan D.; Mitchell, Ria L.; Dzombak, Rebecca M. (February 2021). "Reconstructing Precambrian pCO2 and pO2 Using Paleosols". Elements in Geochemical Tracers in Earth System Science. doi:10.1017/9781108870962. Retrieved March 25, 2026.
^ Planavsky, Noah J.; Tarhan, Lidya G.; Bellefroid, Eric J.; Evans, David A. D.; Reinhard, Christopher T.; Love, Gordon D.; Lyons, Timothy W. (October 2015). "Late Proterozoic Transitions in Climate, Oxygen, and Tectonics, and the Rise of Complex Life". The Paleontological Society Papers. 21: 47–82. doi:10.1017/S1089332600002965. ISSN 1089-3326.
^ Bao, Xiujuan; Zhao, Hanqing; Zhang, Shihong; Li, Xinlei; Tan, Wengang; Li, Chao; Wu, Huaichun; Li, Haiyan; Yang, Tianshui (2023-01-06). "Length of day at c. 1.1 Ga based on cyclostratigraphic analyses of the Nanfen Formation in the North China craton, and its geodynamic implications". Journal of the Geological Society. 180 (1): jgs2022–022. doi:10.1144/jgs2022-022.

Other references

Dalziel, I. W. (1997). "Neoproterozoic-Paleozoic geography and tectonics: Review, hypothesis, environmental speculation". Geological Society of America Bulletin. 109 (1): 16–42. Bibcode:1997GSAB..109...16D. doi:10.1130/0016-7606(1997)109<0016:ONPGAT>2.3.CO;2. S2CID 129800903.
Li, Z. X.; Bogdanova, S. V.; Collins, A. S.; Davidson, A.; De Waele, B.; Ernst, R. E.; Fitzsimons, I. C. W.; Fuck, R. A.; Gladkochub, D. P.; Jacobs, J.; Karlstrom, K. E.; Lul, S.; Natapov, L. M.; Pease, V.; Pisarevsky, S. A.; Thrane, K.; Vernikovsky, V. (2008). "Assembly, configuration, and break-up history of Rodinia: A synthesis" (PDF). Precambrian Research. 160 (1–2): 179–210. Bibcode:2008PreR..160..179L. doi:10.1016/j.precamres.2007.04.021. Retrieved 6 February 2016.
McMenamin, M. A.; McMenamin, D. L. (1990). The emergence of animals: the Cambrian breakthrough. Columbia University Press. ISBN 978-0-231-06647-1.
Nance, R. D.; Murphy, J. B.; Santosh, M. (2014). "The supercontinent cycle: a retrospective essay". Gondwana Research. 25 (1): 4–29. Bibcode:2014GondR..25....4N. doi:10.1016/j.gr.2012.12.026. Retrieved 6 February 2016.
Scotese, C. R. (2009). "Late Proterozoic plate tectonics and palaeogeography: a tale of two supercontinents, Rodinia and Pannotia". Geological Society of London, Special Publications. 326 (1): 67–83. Bibcode:2009GSLSP.326...67S. doi:10.1144/SP326.4. S2CID 128845353. Retrieved 29 November 2015.
Stanley, S. M. (1999). Earth System History. W. H. Freeman & Co. ISBN 978-0-7167-2882-5.
Torsvik, T. H. (2003). "The Rodinia Jigsaw Puzzle" (PDF). Science. 300 (5624): 1379–1381. doi:10.1126/science.1083469. PMID 12775828. S2CID 129275224. Retrieved 24 January 2016.
Weil, A. B.; Van der Voo, R.; Mac Niocaill, C.; Meert, J. G. (1998). "The Proterozoic supercontinent Rodinia: paleomagnetically derived reconstructions for 1100 to 800 Ma". Earth and Planetary Science Letters. 154 (1): 13–24. Bibcode:1998E&PSL.154...13W. doi:10.1016/S0012-821X(97)00127-1. Retrieved 6 February 2016.
http://www.scotese.com/Rodinia3.htm