Earth:Stenian

From HandWiki
Short description: Third and last period of the Mesoproterozoic Era
Stenian
1200 – 1000 Ma
Paleoglobe NO 1040 mya.gif
Paleoglobe of Earth during the Stenian period
Chronology
Etymology
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitPeriod
Stratigraphic unitSystem
Time span formalityFormal
Lower boundary definitionDefined chronometrically
Lower boundary GSSPN/A
GSSP ratifiedN/A
Upper boundary definitionDefined chronometrically
Upper boundary GSSPN/A
GSSP ratifiedN/A

The Stenian Period (from Ancient Greek:, 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. The name derives from narrow polymetamorphic belts formed over this period.

Preceded by the Ectasian period and followed by the Neoproterozoic Era.

The supercontinent Rodinia assembled during the Stenian. It would last into the Tonian period.

This period includes the formation of the Keweenawan Rift at about 1100 Mya.[1]

Fossils of the oldest known sexually reproducing organism, Bangiomorpha pubescens, first appeared in the Stenian.[2]

See also

Notes

  1. "Organic geochemical study of mineralization in the Keweenawan Nonesuch Formation at White Pine, Michigan". University of Michigan. http://deepblue.lib.umich.edu/bitstream/2027.42/28843/1/0000678.pdf. 
  2. Gibson, Timothy M; Shih, Patrick M; Cumming, Vivien M; Fischer, Woodward W; Crockford, Peter W; Hodgskiss, Malcolm S.W; Wörndle, Sarah; Creaser, Robert A et al. (2017). "Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis". Geology 46 (2): 135–138. doi:10.1130/G39829.1. https://authors.library.caltech.edu/83811/3/2018030.pdf. 

References