1200–1000 million years ago
The Stenian Period (from Greek stenos, "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.
This period includes the formation of the Keweenawan Rift at about 1100 Mya.
- "Organic geochemical study of mineralization in the Keweenawan Nonesuch Formation at White Pine, Michigan" (PDF). University of Michigan. Retrieved 28 September 2011.
- "Stenian Period". GeoWhen Database. Archived from the original on May 12, 2006. Retrieved January 5, 2006.
- James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia. 37 (2): 183–199. doi:10.1080/00241160410006492.