Statherian

{{short description|Fourth and last period of the Paleoproterozoic Era}}

{{Infobox geologic timespan

| name = Statherian

| color = Statherian

| top_bar = all time

| time_start = 1800

| time_end = 1600

| image_map = 1740 Ma paleoglobe.png

| caption_map = Map of Earth during the Statherian, c. 1740 Ma{{citation needed|reason=Description on Wikimedia Commons page is "own work" with no cited sources|date=June 2024}}

| image_outcrop =

| caption_outcrop =

| image_art =

| caption_art =

| timeline = Statherian

| name_formality = Formal

| name_accept_date =

| alternate_spellings =

| synonym1 =

| synonym1_coined =

| synonym2 =

| synonym2_coined =

| synonym3 =

| synonym3_coined =

| nicknames =

| former_names =

| proposed_names =

| celestial_body = earth

| usage = Global (ICS)

| timescales_used = ICS Time Scale

| chrono_unit = Period

| strat_unit = System

| proposed_by =

| timespan_formality = Formal

| lower_boundary_def = Defined chronometrically

| lower_gssa_accept_date = 1991{{cite journal |last=Plumb |first=K. A. |date=June 1, 1991 |title=New Precambrian time scale |journal=Episodes |doi=10.18814/epiiugs/1991/v14i2/005 |volume=14 |issue=2 |pages=139–140|doi-access=free }}

| upper_boundary_def = Defined chronometrically

| upper_gssa_accept_date = 1991

| o2 =

| co2 =

| temp =

| sea_level =

}}

The Statherian Period ({{IPAc-en|pron|s|t|ə|ˈ|θ|ɪər|i|ən}}; {{langx|grc|σταθερός|statherós}}, meaning "stable, firm") is the final geologic period in the Paleoproterozoic Era and lasted from {{Period start|Statherian}} Mya to {{Period start|Calymmian}} Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically.{{cite web | title=Statherian Period | work=GeoWhen Database | url=http://www.stratigraphy.org/geowhen/stages/Statherian.html | access-date=January 5, 2006 |archive-url = https://web.archive.org/web/20060512043023/http://www.stratigraphy.org/geowhen/stages/Statherian.html |archive-date = May 12, 2006}}{{cite journal | author=James G. Ogg | title=Status on Divisions of the International Geologic Time Scale | journal=Lethaia | year=2004 | volume=37 | issue= 2| pages=183–199 | doi=10.1080/00241160410006492 }}

The period was characterized on most continents by either new platforms or final cratonization of fold belts. Oxygen levels were 10% to 20% of current values.{{cite journal |author=Holland, Heinrich D. |url=http://rstb.royalsocietypublishing.org/content/361/1470/903.full.pdf |title=The oxygenation of the atmosphere and oceans |journal=Philosophical Transactions of the Royal Society: Biological Sciences |volume=361 |year=2006 |issue=1470 |pages=903–915 |doi=10.1098/rstb.2006.1838|pmid=16754606 |pmc=1578726 }}

Rafatazmia, controversially{{cite journal| author=Kumar, S.| title=Controversy concerning 'Cambrian' fossils from the Vindhyan sediments: a re-assessment| journal=Journal of the Palaeontological Society of India| volume=54| issue=1| year=2009|pages=115–117| url=http://palaeontologicalsociety.in/vol54_1/v10.pdf}} claimed to be present in Statherian beds in India, may be the oldest known confirmably eukaryotic fossil organism.{{cite journal|doi=10.1371/journal.pbio.2000735|pmid=28291791|title=Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae|journal=PLOS Biology|volume=15|issue=3|pages=e2000735|year=2017|last1=Bengtson|first1=Stefan|last2=Sallstedt|first2=Therese|last3=Belivanova|first3=Veneta|last4=Whitehouse|first4=Martin|pmc=5349422 |doi-access=free }}

By the beginning of the Statherian, the supercontinent Columbia had assembled.{{cite journal |last1=Zhao |first1=Guochun |last2=Cawood |first2=Peter A |last3=Wilde |first3=Simon A |last4=Sun |first4=Min |title=Review of global 2.1–1.8 Ga orogens: implications for a pre-Rodinia supercontinent |journal=Earth-Science Reviews |date=November 2002 |volume=59 |issue=1–4 |pages=125–162 |doi=10.1016/S0012-8252(02)00073-9|bibcode=2002ESRv...59..125Z }}

Approximately 1.7 billion years ago, natural nuclear fission reactors were generating power in what is now Oklo, Gabon.{{cite journal |last1=Davis |first1=E. D. |last2=Gould |first2=C. R. |last3=Sharapov |first3=E. I. |title=Oklo reactors and implications for nuclear science |journal=International Journal of Modern Physics E |date=1 April 2014 |volume=23 |issue=4 |pages=1430007–1430236 |doi=10.1142/S0218301314300070|arxiv=1404.4948 |bibcode=2014IJMPE..2330007D |s2cid=118394767 }}